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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> More carb BS /cgi-bin/YaBB.pl?num=1238061540 Message started by BurnPgh on 03/26/09 at 02:59:00 |
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Title: More carb BS Post by BurnPgh on 03/26/09 at 02:59:00 Tuning for a screaming eagle. We'll deal first with the pilot jet. The 55 was too rich. It idled like crap at start up, i couldn't use the choke at all or it would die, and the stink of unburnt fuel was nauseating. So back to the 52.5. Heres the thing so far as this goes...I never have been able to "master" lancers carb tuning guide. With the 52.5 I can hear a distinct pickup in rpms past 1 turn out but they never go back down no matter how far I turn the mix screw out ( I can't physically tunr my screw out more than 4 turns. It just stops moving)so I can't really find that happy medium. Ive just settled with 2 turns out which did not cure the shutdown backfire with the stock pipe or with the SE and with the SE Im now getting a pretty burst of blue flame out the backend aswell as the backfire on shutdown. Im geussing rich but im new with carbs. Rich right? I feel like an idiot asking. So far as the jet needle, Ive got it at 1/2 spacer right now. Im gunna just ride a bit and check the plug. Feels nice as is though. Maybe go to 1/4 spacer. I get the distinct feeling no spacer would be too much and im just going to do a plug chop to check the main. There's a dandy stretch exactly 1 mi long right by my house for that little adventure. |
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Title: Re: More carb BS Post by dasch on 03/26/09 at 11:38:05 With 52.5 and 2 turns out, can you use the choke now? Do you need it at all, better question? |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 12:03:14 I can use the choke with the 52.5. With the 52.5 nothing seems any different between the stock and SE except for the flames at shutdown. |
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Title: Re: More carb BS Post by SimonTuffGuy on 03/26/09 at 12:17:17 Oh yay... This gets my REALLY excited to start messing with my carb. :-P |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 12:42:32 yea...its tedious. Between trying to find out why i was running rich BEFORE i got the SE and now rejetting im sick of taking off teh seat and tank. On the upside Ive had the carb out so many time I can now have it out in about 10-15 minutes. Probably could do it in my sleep now. |
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Title: Re: More carb BS Post by dasch on 03/26/09 at 12:54:41 If you need the choke (need or "can use"??) you are not rich on idle. On idle only, that is. Flames were there with the stock too, you just didn't see them :-) Too many baffles in the stock muffler. Before going further, here's the mistake I did - I put the K&N cone, HD wide ID muffler, larger idle jet, larger main jet and reduced the washer by 1/2. All in a single sweep. Quickly I realized - it's not gonna work. I kept the K&N and muffler, but soon rebuilt the carb OEM, as it was. And then took it one step at a time. Idle jet first. Then the needle. And then main. I am still on main jet phase ;-) Change, adjust, test, test, test, then move to the next step. My 5 cents. |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 13:02:06 I don't NEED the choke but my bike takes a few minutes to warm up. Always has. And the initially low idle on start up makes me uncomfortable so i have always used the choke for the first 30 seconds or so as directed by the owners manual. With the 55 the idle wasnt just slow it was borderline stalling and choke killed it instantly. I did rev it a bit to warm it up since the choke wasnt an option but the smell and small puffs of black smoke....ugh. As new to carb work as i am even i can tell the 55 is a no go. |
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Title: Re: More carb BS Post by diamond jim on 03/26/09 at 14:54:18 I've been running rich. Today I switched from the #55 pilot jet with bleed holes back to the #52.5 pilot jet. Much better idling and coming back to idle on decel. No change in acceleration. Idle is a little smoother. I had to turn the mixture screw from 1/2 turn out to 1 1/2 turns out. There is now an occasional little pop on decel. I think that #55 was partly responsible for my mileage dropping to 36mpg. |
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Title: Re: More carb BS Post by markbacon on 03/26/09 at 15:05:08 Trad. method of idle circuit tuning is make sure engine's good and hot then:
BUT this won't work if the overrun bypass circuit is clagged up. There's a round cover on the side of the carb, under this is a vacuum diaphragm operating a bypass circuit. If like me you ignore this long enough the drilling in the cover that lets air in/out gets blocked and the bypass stays open when it shouldn't. Idle goes over-rich to the extent that choke isn't needed for the coldest start, exhaust blows white smoke, and you can turn the mixture/air screw in till it bottoms without making a difference. Cleaning it - particularly the drilling in the cover - makes a big difference. |
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Title: Re: More carb BS Post by NewThumperGuy on 03/26/09 at 16:49:30 I'm in the same boat your in right now BurnPgh, a good fuel additive or intense cleaning was suggested to me also. I have yet to have a chance to take the next step but hopefully soon I'll know if it works. Beneficial post thanks. |
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Title: Re: More carb BS Post by odvelasc on 03/26/09 at 17:32:36 I feel you. I have been playing with my new vm for weeks lol (mainly because I work soo much). I used a dyno jet kit. It was probably more than lancers however it was quite easy to tune. Maybe I was just lucky. Anywho, keep at it. There will always be the occasional pop on shut down. Thats just little suzi passing gas lol. I finally got my bike running, however my idle circuit is still too rich. I have gone to the lowest pilot jet I can go to on my carb. I am gonna try playing with air mixture on saturday. If I cannot get it to ilde guess what? I have to pull the darn thing for the 50th time and bleed my pilot lol. That blue flame means its lean I believe. I used to have the same issue when I did not seal my new muffler very well. Have you tried setting the needle to a more lean position? i.e. the washer on the highest part of the needle? Goodluck with your tuning, some of us have a harder time than others. |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 17:32:48 Bypass circuit and in fact every nook and cranny in the carb is clean as a whistle so thats not it as far as tuning the idle mix. What I think I really need is a half step between 52 and 55. Im afraid the 52 is lean as I can turn it from 1 turn out to 4 with no slowing of the engine which means I cant really find that happy place as Ive got no "too rich" reference to turn back in from. With the 55 I could turn it all the way in and not have any slowing of the engine but when i turned it past 1 turn out it would stall out and wouldnt restart. So with either of these Ive only got 1 reference point for tuning with the mix screw. Ive kind of given up on adjusting the backfire out of the equation. Even running ungodly rich with the 55 i still had a backfire on shutdown so I've probably got tiniest exhaust leak somewhere. Ive looked. Couldnt find one but...if I cant adjust the backfire out and im not lean....Im just wondering if the flames out the tailend is a rich signal so I can take an educated geuss as to how far to turn the screw back in. So far as the 55 pilot...went from 45mpg around town to about 30. Between the smell, crappy idle, and mileage drop that was enough to convince me i was rich. |
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Title: Re: More carb BS Post by dr1445 on 03/26/09 at 18:17:57 maybe the 55 with a bigger airjet? that combo might give the result you are looking for. |
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Title: Re: More carb BS Post by SimonTuffGuy on 03/26/09 at 18:21:14 From a quick Google search... It seems like a blue flame suggests a lean mixture. Although, the sites also said it depends on temp, when the blue flame is there, etc. Blue flame doesn't mean it's lean... and running lean doesn't mean you'll get a blue flame. What are you running right now? I'm following the suggestions from diamond jim in what he was running with his intake/exhaust and going similar to that route. I got the tank drained this afternoon and that was all I had time for. My moms birthday was today. :-P |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 19:04:25 52.5 pilot, half spacer (trying 1/4 tonight), 152.5 main and whatever the stock air jets are. 230 pilot and 45 main i believe. I went ahead and took another shot at tuning the pilot circuit. Its a bit better. Not a BANG even with the SE, just kind of a big fart but still has the burst of blue flame. |
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Title: Re: More carb BS Post by diamond jim on 03/26/09 at 19:32:57 Burn, my current carb setup is identical to yours except I have no spacer at all. I removed the space a few weeks after I got the bike last summer. Maybe a month ago I put in two washers to try it just cause so many people on here say that 2 washers was best for them. It didn't run nearly as well. I gave it about 2 full days of riding and yanked out the washers. What type of air filter are you using? |
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Title: Re: More carb BS Post by BurnPgh on 03/26/09 at 22:36:03 emco stock replacement |
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Title: Re: More carb BS Post by BurnPgh on 03/27/09 at 00:53:35 Was at 52.5 pilot at 3 turns out with 1/2 spacer. Still had a shutdown backfire with blue flames but it wasnt super loud. Not gunfire loud. Now at 52.5 at 3 turns out with 1/4 spacer. Significant gain in midrange response and power. I didn't notice much difference between 3/4 and 1/2 spacer but the 1/4 change is quite noticeable. Still no change in the friggin backfire. Turning out to 3 1/4. Maybe that'll dull it down to less than irritating. |
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Title: Re: More carb BS Post by diamond jim on 03/27/09 at 05:37:25 There are two elements you can tune for best performance- fuel delivery and airflow. If you've taken the airbox out, try experimenting with some tubing between the filter and carb. It'll help the carb develop more vacuum which will pull more fuel up through the pilot jet at lower rpms. This should richen the mix to get rid of the backfire and give you noticeably more low end response and power to match your midrange gains. Right now you are trying to compensate for the insufficient vacuum at low rpm by adjusting the mixture screw. When I did my tube my mixture screw went back in until it was only 1/4 to 1/2 turn out for best overall performance. One full turn out and idle would start to drop and 1.5 turns out the engine would start to stumble. The tube really woke my bike up . The LS650 is well known for it's torque. With the tube you are basically recreating the stock air path setup that gives the bike it's famous low end torque. Then you have the benefit of a freer flowing pod filter sitting in the open air for midrange and high rpm. Just about any tube will help. Tuning the tube though will maximize the performance. Combined with your SE muffler it will give you lots of grins! |
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Title: Re: More carb BS Post by Zylar on 03/27/09 at 06:24:02 What altitude are you at BurnPgh? I like to pull my plug to get more mix info, have you tried that yet? What color is it? I'm also a fan of Dasch's method, tune each mod before moving on to the next. Lotsa work, but may be the most reliable way. My moms savage has been modded, and we have all sorts of problems tuning it properly. Mine is stock, and just runs great day in and out. Her bike seems just slightly faster than mine, not enough to warrant the tuning woes, imo. I may try Jim's Kamikaze Intake, the ROI on that one just looks too good to pass up (btw, thanks for all the effort Jim, and all the others who make this place so great), but also easy to undo if I don't like it. Good luck, |
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Title: Re: More carb BS Post by diamond jim on 03/28/09 at 20:50:42 In the pic below, what do the parts numbered 31, 32 and 33 do? http://www.thinkythings.org/savage/assembly7.jpg |
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Title: Re: More carb BS Post by dasch on 03/29/09 at 00:12:31 Transient enrichement valve. It's in the Clymer. Richens the mix temporarely during longer decceleration. Why? Beats me. |
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Title: Re: More carb BS Post by diamond jim on 03/29/09 at 06:43:05 2520322229410 wrote:
Aha. Thanks. |
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