Need help troubleshooting fueling issues
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Need help troubleshooting fueling issues
Hi, I have picked up 2005 883 custom. And put hammer performance 1275 basic conversion kit on it. Added their impact air cleaner and V&H short shots staggered. So the problem I have is that when I give it too much throttle too fast it will start bogging up and refuse to accelerate. Gradually increasing the throttle will slowly accelerate. After the ride there is hissing sound coming from the exhaust as if something was dripping and boiling off inside. I googled that it may be cause by the fuel mixture being too rich and I changed main jet from 185 -> 180 -> 175 -> 170. With 170 main jet the problem is almost gone but i feel like it started to run hot. Oil temp is about 220f and there is smoke coming off the cylinders(probably burning off the dirt). Another thing that it does not make sense to have a smaller main jet with bigger cylinders and less restrictive breather and pipes(stock jet on 883 is 175 if Im not mistaken).
Compression is good on both cylinders, 200psi when hot, so no leaks there.
carb looks clean and everything is good inside.
Am I overthinking it and I should just run 170 main jet and forget about it?
Compression is good on both cylinders, 200psi when hot, so no leaks there.
carb looks clean and everything is good inside.
Am I overthinking it and I should just run 170 main jet and forget about it?
Last edited by cnstntn; Jul 11, 2025 at 06:42 PM.
HDF Community Team
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From: shore of Gitche Gumee
Not sure what others are running with your setup. Someone should chime in soon. On my stock 1200 oil temp is ~200 on warm 80-85F ride.
Last edited by hammer6315; Jul 14, 2025 at 09:51 AM.
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From: Santa Ana, CA
It sounds like your running really lean with that 170. I'd be careful as running too lean can scuff pistons in short order. Make sure you're not masking some other issue by running lean. Have you called Hammer? Talk to one of the guys over there and see what they think. They've aleays been super helpful to me.
The engine kit instructions say start with a 185 and those Hammer air cleaners are huge, so I would imagine you would likely want to be in the 185 range. Is it possible it's some other fueling ussue where it's not getting enough gas to the carb when really getting on the throttle? Timing issue possibly?
The engine kit instructions say start with a 185 and those Hammer air cleaners are huge, so I would imagine you would likely want to be in the 185 range. Is it possible it's some other fueling ussue where it's not getting enough gas to the carb when really getting on the throttle? Timing issue possibly?
Last edited by OCSpringer; Jul 12, 2025 at 12:10 AM.
Road Captain
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From: So Western Ohio
The main jet controls the mixture only at full throttle. From 1/3 to 3/4 throttle the mid-range needle height determines the mix. One thing that must be right on before you start trying to tune a carb is the float level. Too high and you will have a way rich condition. Maybe this is causing your trouble. Choking down the main jet may have helped slow down the excess fuel leaking by. I'd check and set the float height, then try the 185 again. It may even have grit on the float needle or seat which will also let gas flow freely when it shouldn't.
Last edited by Rufus13; Jul 12, 2025 at 12:14 AM.
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Stellar HDF Member
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From: Dallas, Texas
1st thing to do is CHECK FLOAT HEIGHT. What slow jet is in there? All ya mention is main jet. Slow jet and mixture screw have to work with the main jet. Changing main jets randomly is an exercise in futility.
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HDF Community Team
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From: San Diego, CA
190/45 main/slow jets in my basic 1250, oil temp runs around 205-210*. Plugs look good, bike runs great. SE aircleaner and mufflers. What needle are you using in the carb?
John
John
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Intermediate
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I have got 185 main, 45 pilot jets. I assume the rest is stock. Should I adjust float height according to the service manual or there is a different procedure for conversion kit? I just realized I forgot to adjust the idle mixture screw, instructions for hammer kit say to set it to 3 turns and the stock setting is 2 and 1/4.
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From: Santa Ana, CA
A/F screw is probably not a big factor in your issue. If it idles smooth and idle isn't hanging or anything your probably fine. I would follow the manual regarding the float. Another test would be to remove the baffles in the exhaust temporarily and see how it runs.
Last edited by OCSpringer; Jul 12, 2025 at 09:36 AM.