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running rich, fouling spark plug...need help.

14591 Views 12 Replies 5 Participants Last post by  cra5h
this will be the 2nd plug in about 6 months that fouls out while i was on a ride, i jetted my bike about a year ago and it was fine, it was running a little rich so i turned the screw a little...ran good, then i started to get some hesitation and started to sputter...fouled plug.

so i adjusted the screw again, ran fine but i noticed some power loss. now last time i rode it was a little sluggish that morning but by that afternoon it was sputtering and the plug was shot. if i turn that screw anymore then it will be back to stock settings.


anyone have any ideas?
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i just had the same problem as u explained, i had my iridium plug in when it started to crap out, i took it back out and put an old one in and it would then crank up but would run rough, sputter and smoke alot, couldnt go below half throttle or it would die out, i have my bike jetted as well but didnt mess with the fuel/air mixture screw at all, now the bike wont even start, so there is a fuel problem somewheres, i dropped it off at a guys house on sunday and he is gonna look at it and get it running again, he said he hates bikes with snorkels cuz they never run right after that, and then he hates bikes that are jetted cuz i guess it is more work to be done on them or something, i just said get it running and if he jetted down ill tear it back apart and rejet it myself....not sure what it is though maybe its some mysterious bike hater plague running through LA
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LA bike haters virus.


i am just really upset that mine runs fine all the time but when i get in a group of people and start to give it what shes got it screws up on me...

but if i were alone somewhere it would be fine no matter how i ride.

maybe it's stage fright...

let me know what goes on with yours.
it really must be stage fright, cuz me and my cousin made 3 or 4 perfectly fine trips mudding and nothing happened, i go to a friends house for a BBQ and alot of my old friends i use to work with are there and they are seeing my bike for the first time and it craps out infront of all of them...yea i should know around the end of the week if not first of next week what happened
cra5h, are you talking about the air / fuel mixture screw? If your are then it sounds like you are adjusting it the wrong because it sounds like it keeps getting worse (richer). If you are just adjusting the idle then its not going to help your problem.

I have read some good stuff on adjusting the air / fuel mixture. If you don't have a gauge then adjust the screw in one direction until it starts to sputter and then the other direction until it does the same thing. Count your turns while you are doing this and put it half way in the middle.

I haven't had to do this yet so this is the best advice I got.
seems simple enough but the thing is, for me to get to my a/f screw i have to remove the carb...

my snorkel is right in the freakin way, i cant reach to adjust the idle...

i may have to just tear this whole thing down and start over with a new snork setup and everything, but then that will most likely lead to more problems.
i thought the air fuel mixture screw was inside of the carb, am i wrong, i know where the carb drain screw is at and i know where the idle knob is(black plastic)........anyone explain where the fuel air/mixture screw is at or take a pic of the stuff around it

thanks guys
QUOTE ("C1iffburton":3qhf388u)
i thought the air fuel mixture screw was inside of the carb, am i wrong, i know where the carb drain screw is at and i know where the idle knob is(black plastic)........anyone explain where the fuel air/mixture screw is at or take a pic of the stuff around it

thanks guys
The A/F screw is directly on the bottom of the carb. If you have the carb upside down looking at the float bowl you will see it. It doesn't have a phillips head like most do, it has a "D" shaped head on it. I backed mine out with a pair of tweezers then used a dremel tool to cut a slot in the head to fit a flat blade screwdriver. Be carefull if you do this, with the screw out you can damage the needle end of it.
QUOTE ("C1iffburton":3m2nezd3)
i thought the air fuel mixture screw was inside of the carb, am i wrong, i know where the carb drain screw is at and i know where the idle knob is(black plastic)........anyone explain where the fuel air/mixture screw is at or take a pic of the stuff around it

thanks guys
The A/F screw is directly on the bottom of the carb. If you have the carb upside down looking at the float bowl you will see it. It doesn't have a phillips head like most do, it has a "D" shaped head on it. I backed mine out with a pair of tweezers then used a dremel tool to cut a slot in the head to fit a flat blade screwdriver. Be carefull if you do this, with the screw out you can damage the needle end of it.
is there a special tool that i could get to undo it? i could use tweezers as well if need be....but is this A/F mixture screw reachable without having to take the carb out? like for tuning purposes, have all the plastics off and whatever else out of the way and still be able to reach it, i have a feeling the guy that is fixing my bike right now is going to rejet my bike back down and ima have to rejet it back up after he gets it running again
I am sure you can get the tool from honda, but it also comes with the dyno jet kit. You guys said that you have rejetted the carb. What size jets are you running? Where did you set you needles at? and how many turns out is you A/F screw?
QUOTE ("fourdig":26afgww9)
I am sure you can get the tool from honda, but it also comes with the dyno jet kit. You guys said that you have rejetted the carb. What size jets are you running? Where did you set you needles at? and how many turns out is you A/F screw?
The tool from Honda is very expensive, or so I've been told. I am running a #165 OEM main jet and about 2 1/2 turns out on my A/F mix screw. I havn't messed with the needle and mine runs pretty good. Depending on where you ride and what elevation it is determines your jetting. I am in TN so the 165 works good for me.
i am thinking of going down to a lower jet and leaving my a/f set the same to see what will happen. i think the stock jet is 160 right? i know i am running a 175...
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