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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> jetting help /cgi-bin/YaBB.pl?num=1239717771 Message started by Mortation on 04/14/09 at 07:02:51 |
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Title: jetting help Post by Mortation on 04/14/09 at 07:02:51 My bike was over jetted with a 155 main, a 55 pilot, stock air box, and three washers in place of the white spacer. I changed to 152.5 main and a 52.5 pilot. Sounds great, runs great at idle, and smooth throttle control. However when riding the bike if I roll hard on the throttle I get sputtering and hesitation or if I let the RPMS get to high same deal. I did not change the washer spacing, its still 3 washers. Thoughts? |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 07:08:00 Maybe I should have stayed with the 155 main? |
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Title: Re: jetting help Post by verslagen1 on 04/14/09 at 07:20:38 try 2 washers |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 07:23:04 352631302F2224262D72430 wrote:
I can do that. Think I can get to it without pulling the carb again? Such a PITA! |
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Title: Re: jetting help Post by prechermike on 04/14/09 at 07:38:22 You can defientely do that without pullig the carb, but you do have to pull the tank. That is what I did when I did the spacer thing. |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 07:47:17 3E3C2B2D262B3C2327252B4E0 wrote:
Tank I can cope with the carb is a real PITA. Thanks. Its rediculas to get the carb off I have to remove the Seat, Tank, Side Covers, Battery, Battery box. These things might not be "complicated" but everything sure is CRAMPED. |
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Title: Re: jetting help Post by bill67 on 04/14/09 at 08:55:44 When you go full throttle your on the high speed jet I would try going back up on it first leave the low like you have it now |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 08:57:33 606B6E6E3435020 wrote:
Yea thats what I was thinking, back to the 155 main. I am going to try and go 2 washers as recommended since I dont have to pull the carb for that. If that doesnt work I will go back to the 155. |
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Title: Re: jetting help Post by matt_savage on 04/14/09 at 10:48:18 Report back to what you find, cuz I'm sorta in the same boat. I just re-jetted mine to 52.5 pilot w/ bleed holes, 152.5 main and 2 of lancer's washer's on the needle jet. I haven't been able to run/fine tune mine yet due to other mods, but would love to hear what you find out. By the way what muffler are you running mort? I have a 1200 sportster muff I'm running that has a 1/2" hole drilled in the baffle to make it louder and more free flowing. I'm thinking I may need the 155 main jet too since I have the pod filter and the free(er) flowing exhaust. -matt |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 10:53:13 6B67727259756770676163060 wrote:
I have a stock air box and Harley muffler with no baffle. Mixture screw is out 1.5. Yours do the same thing? |
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Title: Re: jetting help Post by LANCER on 04/14/09 at 10:59:21 6A68757366736E6869070 wrote:
If by that you mean you are going wide open throttle then it sounds too rich in the high range, which would mean going down to a #150 main jet. |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 11:02:00 636E616C6A7D3D380F0 wrote:
If by that you mean you are going wide open throttle then it sounds too rich in the high range, which would mean going down to a #150 main jet. [/quote] Yea, if I roll on the throttle hard like to accelerate quickly the bike jerks, sputters, hesitates. Hmm, didnt do it with the 155/55 setup. Isnt 150 stock? |
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Title: Re: jetting help Post by matt_savage on 04/14/09 at 11:04:42 I havent had a chance to tweak/fine tune my setup with the mix screw since my bike is still under the knife, but before when it was running it was about 2 turns out and still had a small backfire on shutdown. |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 11:06:12 74786D6D466A786F787E7C190 wrote:
Yea I don't think thats gonna go away ever. My biggest gripe was all the bike firing on decel. Its embarrassing :P But that pretty much went away with the jets. |
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Title: Re: jetting help Post by matt_savage on 04/14/09 at 11:09:26 back firing on decel most times has to do with exhaust leaks. I had a little popping on decel and when I checked my exhaust connections the header bolts were a little loos as was the connection with the header and muffler. I tightenend both of these up and popping on decel went away. |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 11:10:52 606C7979527E6C7B6C6A680D0 wrote:
True, but I have no baffle so I always have a leak lol. No back pressure. So I needed to rejet to fatten it up to try and compensate. |
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Title: Re: jetting help Post by Reelthing on 04/14/09 at 16:30:15 696B767065706D6B6A040 wrote:
If by that you mean you are going wide open throttle then it sounds too rich in the high range, which would mean going down to a #150 main jet. [/quote] Yea, if I roll on the throttle hard like to accelerate quickly the bike jerks, sputters, hesitates. Hmm, didnt do it with the 155/55 setup. Isnt 150 stock? [/quote] 145 is stock unless your a 86-88 bike - 155/55 is getting pretty dang big |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 17:29:10 16212128302C2D2A23440 wrote:
Bike is an 88. I went to 150 per Lancers recommendation. Better but still has the same problem but I do have more throttle range. I couldn't really hit it hard cause its late and the bike is loud. I will give it a real go in the AM and see how it rides. So as of right now I have a 150 main, 52.5 pilot, 3 washers in place of white spacer, stock air box, baffle free harley muffler. Mixture screw 2 turns out. Also, have a NGKDPR7EA-9 plug Not sure where to go from here. I am thinking of going back to the 155/55 setup and toss on a cone filter in place of the snorkel (it will fit right?). At the 155/55 setup it was very rich, trashed a plug and black soot at the end of the muffler. BUT it had full throttle range and little to no back firing (w/ a clean plug anyway). |
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Title: Re: jetting help Post by botwrong on 04/14/09 at 18:06:46 I think i'm having the same problem, already did the washer trick, don't remember how many, was running great with stock muff (no backfiring) put on one of those "mufflers" that have different size openings on each end. Bike is now just loud enough to be obnoxious, which is perfect for me. Throttle response seems much better, but under hard acceleration, seems to just hesitate. I've been lurking here for a while, but my brother just gave me the bike I've been riding, so now I can do what I want to it. 86 ls650 spacer trick, cover removed from air box, new muff. other than that mostly stock. |
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Title: Re: jetting help Post by Mortation on 04/14/09 at 18:32:38 I would also like to point out some inconsistency between my carb and the fiche image. http://suzukisavage.com/images/uploaded/Mikuni_101web.jpg According to the fiche the main jet should have 1 washer. My carb has 2 washers. I also had two washers for part 7 but I took one out. |
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Title: Re: jetting help Post by T Mack 1 on 04/14/09 at 19:09:28 two washers on the main jet will lower it away from the needle and make the bike run rich. |
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Title: Re: jetting help Post by Reelthing on 04/14/09 at 21:40:52 4A48555346534E4849270 wrote:
Bike is an 88. I went to 150 per Lancers recommendation. Better but still has the same problem but I do have more throttle range. I couldn't really hit it hard cause its late and the bike is loud. I will give it a real go in the AM and see how it rides. So as of right now I have a 150 main, 52.5 pilot, 3 washers in place of white spacer, stock air box, baffle free harley muffler. Mixture screw 2 turns out. Also, have a NGKDPR7EA-9 plug Not sure where to go from here. I am thinking of going back to the 155/55 setup and toss on a cone filter in place of the snorkel (it will fit right?). At the 155/55 setup it was very rich, trashed a plug and black soot at the end of the muffler. BUT it had full throttle range and little to no back firing (w/ a clean plug anyway). [/quote] No idea what Lancer told you to do - did he know it was a '88 carb? - very different carb jets wise than '95+ - stock on yours was a 155/47.5 and your needle did not need any washers it was a different needle than '95+ carbs.... I haven't been watching the post lately sorry.... |
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Title: Re: jetting help Post by Reelthing on 04/14/09 at 21:45:22 2F2D303623362B2D2C420 wrote:
two washers on the main jet is a mistake - get rid of one - as lng as we talking about the factory washers - fairly thick brass? or something else? you had two #7's? - someones been funk'n with you crab - need to get it back to where it started and tune from there |
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Title: Re: jetting help Post by PTRider on 04/14/09 at 21:50:23 Quote:
Wrong part. Look at part #4, the spacer. If a substitute spacer is used that is thinner, the needle is lifted for a richer mid-range mixture. My spacer measured about 2.7mm. Three 3mm washers measures about 1.5mm and works well for me on my 2001. The #7 washer has a different function and remains as shown. |
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Title: Re: jetting help Post by Reelthing on 04/14/09 at 22:06:41 1F1807540 wrote:
Now dang it - there's a spring that goes in the hole and washer that goes over it in goes the needle with a clip next is the white spacer and the plate - dimple down if I remember correct and 2 number 1 phillips screws on a 1988 he does not need to do the routine white spacer/ washer lift in fact on a few through 86-87 the needle had 3 different slots for the clip My fear is he is being given advice for a 95+ carb and that is not what he has |
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Title: Re: jetting help Post by Mortation on 04/15/09 at 05:05:13 192E2E273F2322252C4B0 wrote:
Not sure what you mean by it doesnt need any washers... 192E2E273F2322252C4B0 wrote:
Thats what I was thinking. The washers are brass, look like I would expect from what I have seen in other carbs except I expected one and got two. The two washers together bring the bottom of the head of the main jet plum with the lip of the carb tube that the main jet screws into. If I removed one of the washers the main jet would be slightly recessed into the tube. Do you know how thick the stock washer is? If so I can measure one of the washers with my digital calipers. 192E2E273F2322252C4B0 wrote:
Thats what I thought. I expected spring, washer, clip, spacer. What I had was spring 2 washers, clip spacer. I removed one of the washers. I didnt measure the white spacer when I pulled it. But I have it, I can measure it. I still have a whole baggy of them too from other bikes I have done. 192E2E273F2322252C4B0 wrote:
I did not check the needle to see if it was adjustable. I was under the impression for the most part OEM adjustable needles disappeared in the late 70's when the EPA started making stricter rules. I have had to replace the white spacer with washers on many carbs. Are you saying for my 88' using the three washers in place of the white spacer raised the needle to much making it to rich? Should I put the white spacer back in? |
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Title: Re: jetting help Post by Reelthing on 04/15/09 at 06:38:19 I am saying the common fix to raise the needle on '86-88 wasn't needed by default because it wasn't a lean running carb from the factory like the '95 and later carbs - they are different. The needle on some of 86-88's have three groves on the needle so instead of changing the thickness of the white spacer you could just move the c-clip to a different grove to richen or lean the mid-range. Read this spec on the carbs... http://suzukisavage.com/cgi-bin/YaBB.pl?num=1098869040 |
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Title: Re: jetting help Post by Mortation on 04/15/09 at 06:40:52 Well the results are in. I rode the bike to work and its better. I would say I can now hammer to 1/2 throttle without issues. "normal" riding is fine, like around town. If I go WOT or hammer hard beyond 1/2 throttle I go back to the popping, jerking, and hesitation. So I am thinking remove my extra washer on the pilot and give it a shot. If still not better add another washer to the needle. Thoughts? |
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Title: Re: jetting help Post by Mortation on 04/15/09 at 06:48:37 6A5D5D544C5051565F380 wrote:
Hmmm ok. I have checked out that thread before. I will try my above thoughts and if that doesnt solve the problem I will put the white spacer back in. Do you know which groove was the stock setting? I will check my needle tonight and see if it has grooves. |
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Title: Re: jetting help Post by Reelthing on 04/15/09 at 07:16:14 Was in the center - but I believe an '88 only had one you'd have to look - the EPA had not had it's way with the carbs yet like was done with 95 and up - if it is an '88 carb and hasn't been replaced - I'd go back to the stock jets and work up from there - you should have had a 155/47.5 to start with |
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Title: Re: jetting help Post by Mortation on 04/15/09 at 19:42:40 Well I am at a lose. Spent yet another whole night messing with this thing. Found a combo that works well but can't possibly be right. Needle: Spring, Washer, Clip, 2.4mm White Spacer Main Jet: #155, one (OEM?) brass washer Pilot: #52.5 Mixture Screw: 1.5 Turns out Seems the main is the issue. If I put anything but the 155 in at mid - full throttle the bike seizes up, sputters, and jerks. To tired to give this anymore thought tonight. Will see how it rides in to work tomorrow. Before this setup I couldnt even hit 50. I took it out an hour ago with the above mentioned setup and hit 50+ no problems. |
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Title: Re: jetting help Post by Mortation on 04/16/09 at 11:30:56 Well this carb is truely messed up. Still runs like poo, guess I didnt push it hard enough last night. Looking at this picture: http://suzukisavage.com/images/uploaded/CarbTopweb.jpg I am missing the part "I don't know" and its not mentioned in the suzuki fiche so I cant order it :( The main I pulled out of this carb was a 132.5 according to Suzuki the OEM main was a 155 (no wonder the bike likes that better). ARGH!! Anyone know what "I don't Know" is and where I can get one? |
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Title: Re: jetting help Post by NewThumperGuy on 04/17/09 at 16:29:30 Man, that carb shines. Mine doesn't look like that! :-? |
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Title: Re: jetting help Post by Mortation on 04/28/09 at 05:03:45 Well that was a waste of time on money :P I dont have two jet on the top of an 88 carb :( I have a pilot air jet where the pic shows "I don't know" and just a hole where it is marked "Pilot air jet" which goes down to the second diaphragm thing. Behind the second little diaphragm was another jet which I pulled out and cleaned and then put back in. Sooo I re-cleaned everything. Put it back together. STOCK (From: http://suzukisavage.com/cgi-bin/YaBB.pl?num=1098869040): =============== Main Jet: #155 Main Air Jet: 0.6mm Jet Needle: 5c17 Needle Jet: X-6 Throttle Valve: #125 Pilot Jet: #47.5 Stater Jet: #22.5 Pilot Screw: 3 Turns Out Pilot Airjet 1: #67.5 Pilot Air Jet 2: 2.0mm =============== My Settings: =============== Main Jet: #155 Main Air Jet: 0.6mm (I assume, could not find this jet) Jet Needle: 5c17 (Spring, Washer, Clip, 2.4mm White Spacer) Needle Jet: X-6 (assume, did not change) Throttle Valve: #125 (assume, could not find) Pilot Jet: #52.5 (From Lancer Kit) Stater Jet: #22.5 (Assume could not find) Pilot Screw: 1 Turn Out (To start testing) Pilot Airjet 1: #67.5 (New from Ron Ayers) Pilot Air Jet 2: 2.0mm (Assume, could not find) =============== I think I may go grab a cone air filter instead of putting the air box back in. I am up in the air on it. Not sure if I want to loose my side covers or mess with moving the battery box back but I REALLY hate how cramped the spacing is in there for everything. |
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Title: Re: jetting help Post by Reelthing on 04/28/09 at 06:54:07 That pilot jet may workout for you - but that's 2 sizes up for a 86-88 with a stock mainjet - the old rule-of-thumb for the relationship between the two for a starting point was for each 2-3 sizes up on the mainjet you go up 1 on the pilotjet - if such an old outdated rule holds true in this case you would need a 165 to a 170 mainjet to match that pilotjet - which of course is too much fuel unless some pretty radical mods had been done to the air flow. |
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Title: Re: jetting help Post by Mortation on 04/28/09 at 07:35:35 0334343D2539383F36510 wrote:
Hmmmm I dont think I have anything smaller for the pilot than the 52.5 :( |
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Title: Re: jetting help Post by Mortation on 05/02/09 at 16:56:40 OK here is where I am at. I completely disassembled and re-cleaned the carb. I re-assembled with the following specs: My Settings: =============== Main Jet: #155 Main Air Jet: 0.6mm (I assume, could not find this jet) Jet Needle: 5c17 (Spring, Washer, Clip, 2.4mm White Spacer) Needle Jet: X-6 (assume, did not change) Throttle Valve: #125 (assume, could not find) Pilot Jet: #52.5 (From Lancer Kit) Stater Jet: #22.5 (Assume could not find) Pilot Screw: 1.5 Turns Out (To start testing) Pilot Airjet 1: #67.5 (New from Ron Ayers) Pilot Air Jet 2: 2.0mm (Assume, could not find) =============== I also went with a Raptor Petcock and an Emgo 12-55754 air filter (Which I WAY overpaid for!). I also still have the harley muffler with no baffle. No more hesitation or power issues. I took her out tonight and really ripped on her and she ran very powerful. There is still some popping now but not nearly as bad as originally. I am going to run it for a few days and see whats up. I am sure the mixture screw will need some tweaking. I am still thinking about going with a 160 main and 4 washers in place of the 2.4mm white spacer to try and squash the last of the popping. Whats everyone's thoughts on that? |
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Title: Re: jetting help Post by verslagen1 on 05/02/09 at 17:04:41 go up an 1/8 to 1/4 turn on the idle and recheck for popping. Some is ok [smiley=evil.gif] You want to minimise the shut off pop. When I get others, I look for leaks. |
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Title: Re: jetting help Post by diamond jim on 05/02/09 at 17:07:34 Are you certain the little bit of popping left is not due to some exhaust leaks. Even the smallest leaks will cause some minor backfiring. And I don't know if you can get it to where you never have a mild backfire every once in a while. If I were you, I'd loosen the header bolts, header heat shield and the muffler mounting bolt til you've got just a little bit of play in the whole exhaust. Then snug up the header bolts. Gently move the exhaust a little more and check the header bolts again. The goal here is to have the best exhaust gasket seal you can get. Then tighten up the heat shield then the muffler mount. Also check to see if you can improve the muffler to header seal. Sometimes it is difficult to get a perfect HD muffler seal outside of a quality weld job. At this point I think it would be better for you to do those things to eliminate potential exhaust leaks than to increase the main jet to a 160 and change the spacer thickness. Do the idle mixture screw changes as well like Verslagen said. If you adjust it just right it makes a big difference. |
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Title: Re: jetting help Post by Mortation on 05/02/09 at 18:25:02 3C2F3839262B2D2F247B4A0 wrote:
I get a burble on shot off not a pop. Like a poof lol. |
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Title: Re: jetting help Post by Mortation on 05/02/09 at 18:27:24 68656D616362686665610C0 wrote:
I already re-did the exhaust. I replaced the header with a shinyer new to me header. The header is sealed up good. The harley muffler was a PITA the PO did not even close to have a seal. So I drove the reducer deeper into the muffler to seal that end then clamped it. On the other end where the reducer connected to the header there was some play no doubt due to the metric/standard size difference. So I wrapped the base of the header with muffler tape then slid it on and clamped it to seal that up. Maybe I will pope it off and see if there is a gap now that it has hardened. Thanks guys. |
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Title: Re: jetting help Post by diamond jim on 05/02/09 at 18:33:18 Then the pilot jet and air mixture screw setting are indeed your likely suspects for the popping. |
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Title: Re: jetting help Post by odvelasc on 05/02/09 at 18:41:34 2A28353326332E2829470 wrote:
I get a burble on shot off not a pop. Like a poof lol.[/quote] I get decent poof on mine as well. Almost a pop-poof lol. I have a small leak where my exhaust connects to my header. When I shift between 2nd and 3rd I get a pop, pop and I love it lol, but I have to fix the leak. I know I have it because I used aluminum tape to cover up the mess I made sealing up the exhaust and it now has some black soot around where it leaks. |
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Title: Re: jetting help Post by diamond jim on 06/04/09 at 10:39:39 Hypothesis- I think the common spacer mod- thinning the spacer or replacing the spacer with a couple of washers- still leaves a too lean midrange that we often compensate for by over-jetting the main and sometimes the pilot. Background- I've been running a 55 pilot w/ bleed holes, 1 turn out, 2 washers and 155 main. It's has a nice,smooth acceleration. However, gas mileage stinks so I've been wondering if I'm running too rich across all jettings. Today, I put in the 145 main and went for a ride. I had a very significant flat spot in the midrange with power returning on the high end but not quite as much as with the 155 main. Then I removed one washer and went for a ride again. Still a midrange flat spot but not quite as bad. Put in the 152.5 main and the flat spot was reduced to a barely noticeable spot and high end performance improved. Installed the 155 again and midrange was restored with a nice linear acceleration but high end no better than with the 152.5 main. So I discovered that 2 washers, and to a lesser extent 1 washer, is too lean for good midrange and that the overly rich pilot and main jet was hiding this fact. Here's my thoughts: This is what I feel is an illustration of ideal jetting. The jets are even and overlap evenly with no significant overly rich or lean spots. http://i255.photobucket.com/albums/hh128/russ_diamond_jim/jettingcomparison-1-1.jpg In comparison, this is stock. The pilot jet (with the factory idle mixture screw setting) and needle spacer make for a too lean condition but the main jet really is not all that bad especially with the stock airbox and stock muffler or unmodded HD muffler. http://i255.photobucket.com/albums/hh128/russ_diamond_jim/jettingcomparison-1-2.jpg Doing the idle mixture screw mod and thinning the spacer to 2-3 washers fattens up the idle and midrrange areas and improves performance. http://i255.photobucket.com/albums/hh128/russ_diamond_jim/jettingcomparison-1-3.jpg Going to a 55 pilot jet fattens up the idle circuit even more. So does going to a larger main jet. The result is increased overlap on both ends and starts to compensate for midrange leanness of 2 washers. http://i255.photobucket.com/albums/hh128/russ_diamond_jim/jettingcomparison-1-4.jpg Going up another on the main increases the overlap and reduces the gap between pilot and main providing even more compensation for lean midrange. Performance improves but at the expense of running overly rich in the pilot and main. http://i255.photobucket.com/albums/hh128/russ_diamond_jim/jettingcomparison-1-5.jpg So I'm thinking the most ideal baseline carb setup is: Pilot: 52.5 (2-3 turns out) with airbox 55 without bleed holes (1 turn out) with pod filter Spacer: no spacer (regardless of intake) Main: 145-152.5 (depending on intake and exhaust) Just my thoughts on the issue. |
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Title: Re: jetting help Post by BouleTard on 06/04/09 at 12:40:54 Quote:
So what you're saying is, the carb chart that shows what component affects what range.. is only a rough guide. It says the main only comes into play at the top 1/4 throttle, which you've shown is bunk when you're dealing with the larger jets. They not only richen their respective range, but bleed into the adjacent range more, and even main-to-idle circuit if the main is large enough. :o Cool, I'm going to try to get into my carb today and remove the spacer, clean the (stock) main jet and tune the idle screw, with dyna muffler installed if I get that far.. never had any luck fine-tuning the idle mixture by the idle speed method, will listen for pops instead. Thanks! |
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Title: Re: jetting help Post by diamond jim on 06/04/09 at 12:55:27 That was what I saw when experimenting today. I think with the larger main jets the fuel starts to seep out around the needle taper in the midrange section whereas the smaller main jets either don't or do so to a lesser degree. |
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Title: Re: jetting help Post by DrunkenDwarf on 06/04/09 at 19:37:00 Just when I think I understand... I'm running 55 pilot and 155 main with stock airbox and dyna exhaust (all from previous owner) and I'm definitely too lean mid throttle. I was going to try some washers, but I guess I'll start with no spacer and see what happens. I suspect I'll find myself in D. Jim's position of running fine, but low gas mileage. -D. Dwarf |
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Title: Re: jetting help Post by diamond jim on 06/04/09 at 20:09:15 31383D342E393D5C0 wrote:
So your rich pilot and rich main really reveal the leanness of the midrange. Were it mine, I'd try removing the spacer, dropping the main to a 152.5 and set idle mixture screw between 1/4 to 1 full turn. You may be a little rich but you would be more evenly rich. Then fine tune from there. |
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Title: Re: jetting help Post by BurnPgh on 06/05/09 at 00:58:00 DJ - Very well described. Id use it as a Jetting 101 guide. Possibly to be thrown into the Tech section. Altitude will probably throw that off to an extent as will individual bikes themselves but as a basic guide its very handy. Humidity also plays a considerable role, at least in my area. When it's very humid i can definately tell the bike is running a bit richer, though not to the extent that rejetting is needed for rainy weather. In my experience, as far as the spacer goes, it really depends. Some people have removed their spacer altogether to have their bikes bleed gas out of the airbox at idle without touching the pilot jet(i think the airbox. I know people have reported gas bleeding out of somewhere due to this. No spacer works for my bike but it does better with 1 washer (and i suspect it will do better with 2 washers ie half spacer ) owing to the fact that Im too rich with a 55 bh pilot no matter what else is going on - back to 52.5 w/bh - with that im far out on the adjust screw but i have managed to eliminate the shutoff backfire. 52.5bh and no spacer creates sluggish acceleration. Add to this a 155 main and it makes for an all around crappy ride. So I added a washer ( 52.5bh, 1 washer, 155 main) Mid range was much better but it was very apparent when the main circuit kicked in. Still no shutdown backfire. Changed the 155 to 152.5. Idle good, midrange good, main circuit kick in less evident but still noticeable. Switched the main to 150. This is where I stand now - 52.5bh,1 washer,150 main. I still have just the slightest hesitation on the main circuit. I did 4 plug reads between all this. Once for each circuit and the one im running now which still shows a bit rich. I ride mostly mid range so that tells me one more washer may do me good. I could go to a 147.5 main probably instead but while that may eliminate the rich midrange im pretty sure it would make the main circuit too lean. Only by a bit but Im in no hurry to burn up a valve like some have done. I feel another washer would lean the midrange to where it should be and lean the main circuit just enough. A 147.5 may be in my future though. Basically it all overlaps to a fair extent and its a PITA to rejet no matter what. Your observation relayed the basic information found in a dozen or more posts from years ago in one quick easy to read guide. Anyone thats rejetting though will still have to have a starting point (stock jetting with a stock bike or as rich as lancers kit allowed with my SE, which has a baffle but might aswell not have. I can see right through the thing). From there it's best still to pay attention to the bikes feel aswell as do a plug read for each circuit starting with the pilot and working up. Still going to have to open the carb up a bunch of times and take the tank off a bunch of times. It all comes down to trial and error within a certain range of possbilities and Im not the only one thats remarked that this carb never seems to be JUST right. I believe someone here wished they made a 53.5 pilot and I would agree. Or a 148.75 main. If you're rejetting you're rejetting for economy or power. Suzuki's pretty much played out the economy side so...if your doing it for power you might aswell do it right and get the most seamless transition between circuits as possible, and thats no fun...although for me it became fun. With my raptor petcock i can go from seat on to rejetted and seat BACK on in about an hour with all circuits changed. I switched from no spacer to 1 washer in a friends driveway at a party in the dark in 45 minutes (I lost the remaining bits of lancers jet set. Too much wine). Im pretty proud of myself though. Dwarf - I'm guessing you'll want to drop to a 52.5 with bleed holes and adjust the mix screw, a 152.5 main, and 1-2 washers. No telling really without doing it step by step. 55, no spacer, 155 is pretty rich all around. I don't think you'll like it but it will probably run. 52.5 ad adjust will probably be good, with no spacer will probably be okay, with 155 main will probably be rich. Add 1 washer and you're pilot will probably still be okay with a mix screw adjust. You're midrange will probably be better. Your main circuit will probably still be rich. Add 1 more washer your pilot may still be good with mix adjust. If so your midrange will be even better. Your main circuit will be way to rich. You'll feel it bog down at high revs. Switch to 152.5 main. Hows that suit you? Do a plug chop on the main circuit. Still rich? Go to 150 main. Check the plug again on the midrange. If it's lean remove one spacer. I've been typing and aditing for two hours to try and get this across simply and to be honest its just trial and error. Dwarf. Pm me as you go along and I'll help you out. |
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Title: Re: jetting help Post by BouleTard on 06/05/09 at 08:36:12 diamond jim, Well I got the white spacer removed and cleaned the jets on my carb yesterday. Stock jets (I think) are 52.5 pilot and 145 main. The pilot jet was almost completely clogged.. no wonder afterfiring was excessive. I cleaned both jets, buttoned it back up, and swapped the stock muffler for the dyna. At that point is was too late to do anything but idle, but it fired up 1st crank and idled great, pilot screw 1.5 turns from seated. I'll seal up the muffler joint today and take it for a spin.. maybe tune the fuel screw better. That should hold me until Lancer sends me one of his slide carbs with the tuning manual and assortment of jets. Ride report later... 8-) Edit-- ride report along with setup summary in "carb jetting- a progressive guide." Fattening up the midrange worked wonders for me. |
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Title: Re: jetting help Post by diamond jim on 06/05/09 at 09:04:39 I got some pilot jets in the mail today. I should be getting the stock 52.5 today or tomorrow that Lancer hooked me up with since I couldn't find mine. Here's all the pilot jets I have now: 50 w/ bleed holes Stock 52.5 52.5 w/ bleed holes 55 with no bleed holes 55 w/ bleed holes For main jets I've got: 145 147.5 150 152.5 155 |
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Title: Re: jetting help Post by DrunkenDwarf on 06/05/09 at 09:35:31 2E232B2725242E2023274A0 wrote:
1F282F330D3A355D0 wrote:
Thanks for the advice, both of you. Cutting the engine in 4th at WOT terrifies the bejeezes out of me. I've only been riding for a few months. I tried the WOT roll-off to 7/8 test today on my way to work in 4th. I was doing 60-70 mph at the time. I didn't notice the engine hesitate or gain power. So either I screwed up the test, or I'm not excessively rich. I'll retest on my ride home. The only jets I have are the stock and the 55/155. Sounds like I need to go jet shopping. I did finally find some 3mm stainless washers. So I've got that option. Would removing the airbox door increase airflow? That was something else the previous owner did. It doesn't seem like it would make much difference with the side panel installed. Finally, the previous owner suggested the keeping the circuits a little on the rich side would make the engine run cooler and reduce the bluing of the header pipe. Based on what I've read, that sounds accurate. -D. Dwarf |
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Title: Re: jetting help Post by diamond jim on 06/05/09 at 10:58:03 On Dan's motorcycle and repair site, he said he's seen some bikes that don't run worth a flip if there is even a crack in the airbox while others run fine when opened up. The LS650 is one of those that runs fine when opened up. I don't know if it translates into more air into the carb though or needs different jetting than one with the door in place. |
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Title: Re: jetting help Post by diamond jim on 06/05/09 at 14:32:15 5B52575E445357360 wrote:
I'm at about 45-47mpg now. I was at about 38-40m when all was set up really rich across the board. But I think most of my mpg loss came from the overly rich pilot jet and twisting the throttle and a only a little from reduced spacer thickness. From where you are now, I say lean the pilot, richen the middle and lean the main. |
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Title: Re: jetting help Post by DrunkenDwarf on 06/05/09 at 20:25:11 7A777F7371707A7477731E0 wrote:
I turned out the mixture screw to reduce afterfires, so I'm probably excessively rich at idle. I'll pull the plug tomorrow (first time taking the tank off). My only main jet options right now are 145/155. I'll probably try no spacer and adjusting the idle mixture before I buy more jets. I don't want to make a hobby out of rejetting. No offense. ;D Other than a "plug chop", is there a way for an inexperienced rider to judge the main jet? Story: I was talking to a coworker about my carburetor questions. He's a real car nut. Has a BMW he races. Does all the work himself. Anyway, I was asking his advice and he replied, "It's got a carburetor, be happy it runs." ::) -D. Dwarf |
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Title: Re: jetting help Post by BurnPgh on 06/05/09 at 22:55:24 Got a hill in the area? Mark off on you handle bar 0, 1/3, 2/3 and full throtte. Go up the hill in whatever gear you like and try to pay attention to when you hit the 2/3 mark see if you feel the bike bog down a bit before it picks up again. If so your main jet is rich. You can doit on flat land too but the bog down isnt quite as apparent. |
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Title: Re: jetting help Post by DrunkenDwarf on 06/06/09 at 07:04:20 1E292E320C3B345C0 wrote:
I do have hills. Today I intend on pulling the head cover and tightening the cylinder nuts, but if it doesn't rain tomorrow I'll give that a try. -D. Dwarf |
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Title: Re: jetting help Post by DrunkenDwarf on 06/14/09 at 12:48:47 Sorry about the delay, had the head cover off. Still have an oil leak (shouldn't have put the chrome back on so fast). I rejetted to: 55 (1 turn out) / no spacer / 152.5 The 1/4 - 1/2 throttle surging is gone and the afterfire is reduced. I haven't decided about the main. I want to get the oil leak cleaned up (and do an oil change) before I start playing with WOT. -D. Dwarf |
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Title: Re: jetting help Post by Targett3997 on 06/15/09 at 12:54:59 I have got my carb tuned about right I think...I am still getting the backfire only on the decel, but I have a straight pipe. You guys think that adding some back preassure like a stock pipe would fix this? No accel, decel problems, or shut down problems. Just the backfire on decel, but response is good. As far as I know (bike had a previous owner) the carb is running a 150 main with a 55 pilot jet no bleed holes.(This is what I was told) And the screw is 2.25 out.(I confirmed the screw.) Just trying to get the right tuning on the decel now. Thanks, John |
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Title: Re: jetting help Post by matt_savage on 06/15/09 at 14:25:47 Impossible to get rid of popping or afterfiring with a straight-through pipe on decel. The baffling in most pipes is what controls this popping and afterfiring. -Matt |
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Title: Re: jetting help Post by odvelasc on 06/15/09 at 17:50:33 I was running rich at idle and boy did it kill my gas. I jetted up to a 170 main on my VM carb and did not adjust the air mixture screw at all (oopsies lol). Wow was my bike running awesome, then on a small jaunt downtown it started to bog down as I opened throttle just a tad. I was blowing black smoke. Pulled over and did a total of about 1/4 turn to lean on the air mixture and dialed my dial a jet down to leanest setting. Saved my plug from fouling. I was still getting a crackle on hard decel when in 5th at highways speeds. I get it a tad louder now. So, I am gonna rejet my dial a jet (which serves as the main) up two spots to the middle. I think it should fix things and give me back my top end. I have my needle set to the middle position and with the 170 main I am not getting pops when up shifting at about 1/2 throttle like a used to and I have great mid range response now. Hot diggity dog its frustrating jetting carbs. But it is sooooooooooooo rewarding when you get that bike running happy and you get a smile on your face as your bike improves in performance. 8-) |
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