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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Mystery rich condition? /cgi-bin/YaBB.pl?num=1685425015 Message started by Moarpower on 05/29/23 at 22:36:55 |
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Title: Mystery rich condition? Post by Moarpower on 05/29/23 at 22:36:55 Hi guys. So my savage is finally running really great. I am now trialling the 160 pilot jet and it seems to be working well for WOT performance. I tried to go up from the 47.5 pilot jet but it was running very rich at idle. I have found that the bike will not always stall when the pilot screw is tightened all the way in but it does slow down the idle. I have cleaned the carb fully a few times over the last month. The plastic screw that connects the choke plunger to the carb is also broken so that needs to be replaced. Just having trouble finding the part in stock here in Australia. I went back to the 47.5 pilot and it is running better at idle but I still get a black puff if I give the throttle a little flutter. I am concerned this may be too lean tho. Maybe this is to be expected for my old bike Also, I just wanted to thank you guys for your help. Your knowledge is a great resource and I appreciate you all taking the time out of your days to help those with questions. |
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Title: Re: Idle rich ? Post by ThumperPaul on 05/31/23 at 14:22:51 I read your other recent post about your bike and modifications. You’ve got a lot going on. I black poof could be nothing (afterburn). If it’s running great as you said and not smoking when your riding, I’d just watch it. If the mods were done recently, it could be just about anything. Watch your oil level. I don’t like any color smoke and assume oil bypass because I usually assume the worst. How’s your gas mileage? |
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Title: Re: Idle rich ? Post by Moarpower on 06/01/23 at 01:27:40 Gas mileage is pretty good. 5lt per 100km highway. There is no smoke when riding. And it won't smoke on its own at idle, only one puff when I just slightly touch the throttle. I have gone back to the single hole 47.5 pilot jet for now. The 8 hole 47.5 seemed to run poorly as do the 50 and 52 8 hole jets. I can't seem to dial them in at all. I'll try a larger single hole pilot jet if I can find one. |
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Title: Re: Idle rich ? Post by Dave on 06/01/23 at 03:34:04 If you are running the stock carb......the pilot jets with holes in the side have no affect on the fuel mixture. Those pilot jets are made for carbs that have an air supply to the side of the pilot jets, and the stock carb has no air supply to the area along the sides of the pilot jet. The fuel mixture will not vary if you use the single hole jets - or the ones with holes on the sides...they will provide exactly the same restriction as long as the single end hole is the same. The air that mixes with the fuel from the Pilot jet is provided up in the carb body above the float bowl. Next time you have your carb off remove the pilot jet and look closely down into the recessed hole the pilot jet screws into....and you will not see any passage to permit air to flow to the pilot jet. NOTE: The stock carbs on my little Ninja 250 had holes in the sides of the pilot jet, and a small amount of air was provided to create an emulsion in the body of the pilot jet. When you closed the throttle during and created a high vacuum situation - the Ninja had an air supply valve that would close and stop the air flow to the sides of the jet to resolve the Lean condition that occurs when you close the throttle at higher rpm....on the Savage the TEV does this - and the system on the little Ninja worked much better. So...on some carbs those little metering holes in the side of the pilot jet do work - but not on the Savage. It is my belief that a pilot jet has very little affect on how a bike runs - the affect is mostly on how it idles and how the engine responds when you roll the throttle slowly on.....if you crack the throttle open quickly the needle and main jet are now controlling the mixture.by way of the vacuum operated slide. If you get the smoothest idle with the idle fuel mixture screw 1.5 -2.5 turns out - the pilot jet is sized correctly. If you can turn the screw all the way in without experiencing a drop in idle smoothness, the jet is too big. If you have to turn the screw out more than 3 turns and don't experience a "rich" idle...the jet is too small. All idle fuel adjustments should be made withe the engine fully hot and the idle speed dropped temporarily to around 800 rpm......adjusting the mixture at a higher rpm is not effective as the slide will be opening and you will not get a noticeable change when moving the mixture screw. Once you have experience with this adjustment you should be able to make it in less than a minute or two.....then turn the idle speed back up. |
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Title: Re: Idle rich ? Post by Moarpower on 06/01/23 at 05:26:34 Thanks Dave. Running the stock carb. Throttle from 1/4 onwards is fine with the newer style jets. It just idles poorly on the 47.5 up to the 55 and doesn't like slow take offs. With the single hole 47.5 it idles much better and handles the slow take off without an issue. Not sure what's happening with these jets but they seem to be running very rich. The stock 47.5 runs fine but may be a little on the lean side. |
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Title: Re: Idle rich ? Post by Moarpower on 06/05/23 at 22:52:59 Man this old bike. I love it but I'm almost ready to give up and just stick with my honda. No matter what size pilot jet and pilot air screw settings I use, I get this really poor idle and low throttle sputtering. As you can see by the video I'll link below, it's when I'm only just touching the throttle, which is bad because that's where I am when I am filtering through traffic or driving through a parking lot and it sputters poorly. The video is with a 52m5 pilot, one turn out. I've tried jets from 47.5 up to 55. . It's definitely leading to a rich idle, whatever the issue is. I'm wondering if it could be a low rpm spark issue? I think it could be as it used to just miss every minute ot 2 and have a tiny sputter at idle, but it's progressing now. It's all good wiring and original electrical. |
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Title: Re: Idle rich ? Post by Moarpower on 06/05/23 at 22:53:51 https://youtube.com/shorts/J93Q-b9qvG4?feature=share As soon as I move the throttle a little more it runs fine |
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Title: Re: Idle rich ? Post by Moarpower on 06/06/23 at 00:16:55 Went to start it today and it won't even start now. I went back to the spark plug which was replaced a week ago and it was black again. Replaced the plug, which still didn't want to start, and even gave a couple of pops back through the carb. Spark is blue and pretty bright Maybe the damaged choke is the culprit. The plastic thread is broken and has been like that since I bought it. I'm thinking about replacing the carb entirely. Might even try a cheap eBay knockoff just for fun It is currently using the 160 main jet, back to the 147.5 pilot, a needle with washers to match the plastic spacer size as its broken. Really just want a bike that will run for more than a month at a time at this point. |
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Title: Re: Idle rich ? Post by Moarpower on 06/06/23 at 06:08:37 Update. I bought a cheap Keihin pwk 38 and assorted jets. When they all arrive I'll see how they go..this one ships with 170/55 jets. And a 48-DDJ needle. The carb was only 17aud shipped, less than the jets and less than half the cost of a new plunger assembly. I also bought a new ignition coil and spark plug lead assembly. The old lead is wrapped in electrical tape so it's probably due for a replacement |
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Title: Re: Idle rich ? Post by Moarpower on 06/06/23 at 16:02:38 The EEN needle is almost impossible to find. Wonder if the EEM would be ok. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 01:22:51 I managed to get my factory carb running really well today. I removed the needle again and the stock spacer had almost dissolved. It was really soft and squishy. So it ran incredibly rich for most of the ride time and fouled another plug. I installed a new plug and 4 washers on the needle and no spacer. Had loads of power but was a bit lean. Went to 3 washers on the needle and its now running nice. The only issue remaining is there is quite a bit of free play in the throttle before it lifts the butterfly, and when I'm riding, if I just barely activate the throttle to where it just starts to operate the butterfly, it seems to have a bit of a flat spot or a stutter. Its only present at the slight touch of the throttle. Maybe it just needs the cable adjusted. I also installed a new ignition coil today. The one on the bike was the factory unit from 1986 |
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Title: Re: Idle rich ? Post by Dave on 06/09/23 at 04:17:01 2C0E0013110E160413610 wrote:
That is an indication that the mixture is lean under light throttle just as the slide begins to lift. Remove 1 washer and try 2. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 04:30:21 Thanks Dave. I'll try that tomorrow. Interestingly I didn't notice it with the 4 washers but I only did a quick ride with the 4. It really is only the very first touch of the throttle. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 18:38:17 073C3126373B20263D353827540 wrote:
Removed one washer and the issue is still present. Also seems to be running a little rich with only 2 washers. Maybe the 155 main jet is too big. It my needle and needle jet setup or wrong. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 18:43:18 Here is a picture of the broken choke. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 19:12:52 I'm using the 50 pilot jet and it seems to be the right size. Here is the new plug after 5 minutes riding with some WOT pulls up to 4th gear. Pilot screw set on warm engine, best idle at 1.75 turns. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 19:13:18 Another angle of the plug |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 19:23:13 Here is an image of a new plug yesterday, after an hour of riding through the hills. |
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Title: Re: Idle rich ? Post by Moarpower on 06/09/23 at 19:27:37 I'm going to try again with another fresh plug and lean out the slide a bit. I'll add the 4 washers and see if the issue is resolved with the stutter at the 1 to 3 per cent throttle. Maybe my 155 main jet is too much. Perhaps there is a vacuum issue. |
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Title: Re: Mystery rich condition? Post by Moarpower on 06/10/23 at 00:51:01 Mystery rich condition update. 80kms today of pretty varied riding from slow and easy the hectic revs throughout the hills. I raised the needle with 4 washers, no spacer. This picture is the plug after the ride. I am still struggling with the flat spot/sputter at 1 to 3 percent throttle. Changes to the needle height have had zero impact on this. And it is now the only problem with how this bike runs. But some more detail on this was discovered. It is most prevalent when coasting down a hill in a lower gear/ at higher coasting revs. When I touch the throttle during this time, there is a stutter. However if I go up a gear and lower the coasting revs, the issue is less apparent at that 2 percent throttle. Go up to 4th and it's gone entirely. So it appears it's really only an issue at those higher revs. |
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Title: Re: Mystery rich condition? Post by DragBikeMike on 06/10/23 at 03:10:12 You can't dial in your carb with that broken enricher. The plunger can move in & out at will. Nothing is keeping the plunger on its seat. At small throttle openings, the thing will be nuts. One moment rich, the next moment lean, sometimes normal. A total moving target. As a minimum, find a way to keep the plunger in so that it is fully closed, hard on the seat. Maybe some sort of rubber band setup. I'm afraid to ask what the TEV looks like. Do you even have a service manual? No wonder you are struggling. :o |
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Title: Re: Mystery rich condition? Post by Moarpower on 06/10/23 at 03:48:46 Hi Mike. The TEV and diaphragm are clean with no holes. . I've been zip tieing the plunger in place when I ride. Just cut the tie for the photo. But I'm still looking for another. The bike is riding really well. There is just this last issue I'm chasing now. Hopefully I can find another plunger assembly but I don't think that will fix it unfortunately. It feels like the slide is just hesitant at the start. |
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Title: Re: Mystery rich condition? Post by Moarpower on 06/10/23 at 18:35:45 I have ordered a new plug ger assembly 13411-24C00-000 from webikejapan. Hopefully that helps it run a little better but I'm not sure it will solve the issue. I think I may change my needle and needle jet. Currently it has the 5C17 needle and the x-6 jet. I will measure the main air bleed this afternoon. The issue can only be a handful of of things. The stutter is only at the slightest touch of the throttle when the engine is under load and the revs are up high. |
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Title: Re: Mystery rich condition? Post by Moarpower on 06/12/23 at 00:30:54 Update. With the new plunger Installed the issue has unfortunately shown zero change as I thought it may. My pilot air jet fits a 0.6mm drill bit however, even tho these are numbered, they are cheap bits from Amazon and I'm not sure I trust them to be super accurate. I have 3 of each size and they all felt different with the shaft end in the main air bleed. As it feels like the stutter is where the carb goes from pilot to slide, I tried raising and lowering the needle. While this changed how the bike ran , lean or rich at that throttle range, it did not alter the 1% throttle stutter. So maybe the issue the pilot circuit somewhere. I can idle along very slowly without any problems. And the bike is certainly rideable and rides very well. This is just the final little issue I am facing and is mainly an issue when down shifting and coasting where I first apply throttle. While adjusting the needle I noticed a small resistance or bump when raising the carb slide by hand. Doesn't feel 100 percent consistently smooth at the start. |
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Title: Re: Mystery rich condition? Post by ThumperPaul on 06/12/23 at 09:08:45 Did you address that broken choke? It could be partially stuck on choke and it'll never truly idle right no matter what pilot jet you have in there and air/fuel mix screw set at. You could be "forcing" a tune-up with a defective choke. You are definitely running rich based on the spark plug. The main jet will not affect idle speed at all. The pilot jet exclusively does that. If that choke is partially "on", it will run rich at all engine speeds. Pilot jet does most of its job at idle and for about the first 25% of RPM range, then the slide starts kicking in for the bulk of the mixing in the mid-range (think 25-75% rpm range), then the main is for your top end and high RPM. They all work together, but some are doing more than others at different rpms. I'd resolve that choke if you haven't. Otherwise, I think you're just chasing your tail. |
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Title: Re: Mystery rich condition? Post by Moarpower on 06/12/23 at 13:54:52 Hi Paul. Yes I replaced it. I mentioned it in the last post. I called it a plunger assembly as that's what it's called in the parts diagram. It idles great now. It's just the stutter when coasting with the revs up and just barely touching the throttle that's the issue now. |
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Title: Re: Mystery rich condition? Post by DragBikeMike on 06/13/23 at 00:12:34 There are two very tiny holes in the carb body that get uncovered by the throttle plate just as you crack it open. Those holes are referred to as "transition ports". The transition ports add fuel as the throttle plate uncovers them. When the throttle plate is closed, the transition ports serve as additional air bleeds for the idle circuit, but as the throttle plate moves past the holes they are exposed to manifold vacuum and begin to supply fuel. They help make the transition from the idle circuit to the main jet circuit. That seems like the zone you are having a problem. Make sure those holes are clean. Remove the pilot jet and spray carb cleaner through the idle circuit. Make sure that carb cleaner blasts out of both those holes. These are the two transition ports. |
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Title: Re: Mystery rich condition? Post by DragBikeMike on 06/13/23 at 00:14:55 That "small resistance or bump" you feel when you raise the slide by hand may also be a problem. That could be hard to rectify. Your carb is really old and the photos show it is in very poor condition. If the slide and carb body are severely worn it might not be salvageable. Also, there are two air bleeds in the top of the carb. These air bleeds are for the idle circuit and the transient enrichment circuit. On your older carburetor, one of those airbleeds is just a fixed hole, the other has a removeable jet. On your carb, the fixed hole (circled in green) should be 2mm, and the jet (circled in yellow) should be a #70 (about .028"). You may be able to improve the condition by playing with the pilot air bleed jet (the one circled in yellow). A smaller jet will make the mixture richer, and a larger jet will make the mixture leaner. These are the pilot air bleeds in question. |
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