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Post by lain on Apr 16, 2015 13:35:40 GMT -5
So i changed the jet to a 125 from a 115 and honestly I'm not really seeing any difference, still getting the same popping noise and my a/f screw doesn't seem to affect the idle until it's all the way tightened in then the engine cuts off Doing quarter turns at a time to lean doesn't seem to do anything. Not sure what I'm doing wrong but obviously something. Am I on too large of a jet or what's going on here? Do you have a cam or a phone? Can you record for us to see/hear? |
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Post by lain on Apr 16, 2015 13:39:11 GMT -5
Are you 100% sure the exhaust gasket set in right? I use a tiny dap of grease on the gasket to make it stick to the muffler tube so it doesn't move around while awkwardly positioning the tube to get it on and the nuts on. I also don't tighten the nuts on the tube all the way until the muffler is secured to the frame and the tube. I only tighten them until I feel resistance in both nuts, then I secure the muffler and finally end with finishing off the nuts that connect the tube to the engine.
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Post by dmartin95 on Apr 16, 2015 14:15:18 GMT -5
So i changed the jet to a 125 from a 115 and honestly I'm not really seeing any difference, still getting the same popping noise and my a/f screw doesn't seem to affect the idle until it's all the way tightened in then the engine cuts off Doing quarter turns at a time to lean doesn't seem to do anything. Not sure what I'm doing wrong but obviously something. Am I on too large of a jet or what's going on here? I suggest taking your idle jet up one size. |
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Post by murkyapricot on Apr 16, 2015 19:12:19 GMT -5
I will look into the idle jets tonight, but in the meantime here's a short video of me revving it up, this is after its been running for a little while, as you can see the header is pretty colored already and only after about 25 total miles on it
Anyway maybe this will shed some more light on the subject, but is the idle jet being too small why I'm seeing no difference with the a/f screw?
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Post by geh3333 on Apr 16, 2015 21:46:38 GMT -5
TBA, its idling perfect ! Some popping of decel won't hurt anything. I have it sometimes. Do you have any open vacuum lines ? Did you do a bbk ? What size carb do you have , sorry if I missed it. A 115-120 on a stock bore with the uni and exhaust should be fine. If you have a bigger carb you should already have a bigger pilot in there. You can always try a bigger pilot and see how it goes. Popping on decel is either a leak in the exhaust , vacuum leak , or you a just running lean on decel , which would be pilot related , and can sometimes be fixed with the air fuel screw. Did you tune the air fuel to get the highest idle, then turn the throttle screw down to the current idle ?
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Post by murkyapricot on Apr 16, 2015 22:10:42 GMT -5
TBA, its idling perfect ! Some popping of decel won't hurt anything. I have it sometimes. Do you have any open vacuum lines ? Did you do a bbk ? What size carb do you have , sorry if I missed it. A 115-120 on a stock bore with the uni and exhaust should be fine. If you have a bigger carb you should already have a bigger pilot in there. You can always try a bigger pilot and see how it goes. Popping on decel is either a leak in the exhaust , vacuum leak , or you a just running lean on decel , which would be pilot related , and can sometimes be fixed with the air fuel screw. Did you tune the air fuel to get the highest idle, then turn the throttle screw down to the current idle ? As far as I know all the vacuum lines are where they should be. No bbk standard size carb 24mm I will recheck the exhaust gasket and make sure that's not my issue it rides well, my main concern is the header changing color I've read on some Google searches that it's running too hot if it does that and may cause serious engine problems either way when i had the 115 in i felt like the a/f screw really wasn't causing any noticeable changes For opinions on the pilot, when I bought the carb the size wasnt listed, what's typically the standard size I think i read 30 or 35 somewhere? Does that sound right or am I way off? Edit: i Do have one open line, it was the small hose that led back to the stock airbox, that led to the vent hose, could this be a cause or just unrelated? |
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Post by geh3333 on Apr 16, 2015 22:15:57 GMT -5
I would get a temp gauge , even if its one of the oil dipstick gauges. This way you will know if heat is the problem. In the meantime I would go with a 120 main and up the pilot to the next size. I don't see your engine running that hot with a stock bore stock head and a 115 main with a stock pilot. But I've seen stranger things ,lol
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Post by wilds on Apr 16, 2015 23:18:58 GMT -5
Did you try a bigger pilot jet?
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Post by murkyapricot on Apr 16, 2015 23:29:16 GMT -5
Did you try a bigger pilot jet? that's my next step im looking into it now, seems like stock is 35 so I'm gunna get a few larger sizes anyone have any links where to find them? i keep finding main jets |
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Post by wilds on Apr 16, 2015 23:39:55 GMT -5
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Post by dmartin95 on Apr 17, 2015 13:36:29 GMT -5
Did you try a bigger pilot jet? that's my next step im looking into it now, seems like stock is 35 so I'm gunna get a few larger sizes anyone have any links where to find them? i keep finding main jets I have opened up about 8 24mm carbs and they all had a 35mm pilot. I would say 35mm is a safe bet for stock sizes... I would start with a 38 pilot and see if that fixes the popping on decel. |
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Post by murkyapricot on Apr 17, 2015 13:38:43 GMT -5
How important is the length of the pilot jet? Mine measures in at 23.5mm but every site i see selling them puts overall length at 28mm
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Post by dmartin95 on Apr 17, 2015 15:15:55 GMT -5
How important is the length of the pilot jet? Mine measures in at 23.5mm but every site i see selling them puts overall length at 28mm I don't know. However, I have upjetted using the larger pilots (Keihin style) and haven't had any issues. |
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Post by murkyapricot on Apr 17, 2015 18:37:21 GMT -5
Awesome thanks I'll pick up a 38 and probably a 40 too and see how it runs
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Post by murkyapricot on Apr 22, 2015 18:43:41 GMT -5
Alright so an update, got a better gasket, the kind that has holes for the bolts to go through to eliminated possible exhaust leak
and I also bought a 38 and a 40 idle jet and put in the 38.
still getting the popping noise, maybe not nearly as loud but it's still there on deceleration
one other issue in having is on deceleration it feels like it's slowing down a little too fast theb when it hits a certain rpm starts to coast nicely, but at first it feels like it's decelerating hard
what could be the cause?
also gunna pick up a new spark plug this week so i can get a better idea on how it's running
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