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Fourtrax 300 Issues

2069 Views 6 Replies 5 Participants Last post by  tinkerman
Hey geys new to the forums!

I have a 16' rancher 420, and i believe a 91 Fourtrax 300.

I got the 300 from an older lady who had it and it sat for a while. When I brought it home it would start up perfectly using almost no choke or choke for a few seconds and would idle all day fine. However, when i got on the throttle the carb acted like a 2 stroke in which it had very low power on the low and middle rpm band but would pull fairly strong in the upper rpm's. I immediately replaced the spark plug, oil, oil filter, and discovered there was no air filter so i put one on it. This made a good difference but it still wasn't perfect so I automatically assumed the plastic piston in the carb was probably scratched up and sticking so i ordered a whole new carb instead of dealing with rebuilding it (43$).

Now with the new carburetor the situation has reversed. It has great pulling power in all RPM's (My 420 barely pulls away from it now) but will not idle correctly and its backfiring upon deceleration. It also seems upon steady state cruising to cut out and bog for a few seconds until i heard an audible backfire then it resumes normal operation.

My question is am i looking at a jet problem or possible choke problem? i reused the old choke cable but the choke jet (i guess thats what it is) was different than the old carb and not the same length so there may be extra tension on it even with the switched fully open.

Thanks guys I love Honda (got 2 honda cars as well) and im planning on getting a 350 next weekend!
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You got a China carb which is no good.. Judging by the price I'll bet it was a zoom zoom.. they suck, jets are wrong..Caltric would have been better but they are around 2x the price..

Clean the original carb and/or buy a rebuild kit..




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My experience with backfire is that you may not have the carb seated well in the rubber manifold
Did you get a new OEM carb? They are close to 4 bills now
china carb, worthless, buy carb rebuild kit, read my sticky on how to clean a carb, problem solved for the most part.
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Yes it is a zoom zoom carb and I had gotten good results out of this brand twice before on go karts so I figured why not. I will attempt to rebuild to stocker and see if that works. Thanks for the replies!
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Yes it is a zoom zoom carb and I had gotten good results out of this brand twice before on go karts so I figured why not. I will attempt to rebuild to stocker and see if that works. Thanks for the replies!
really easy bro, a good carb rebuild kit, like shindy, moose, and a few others, but I use shindy mostly. read my sticky on how to rebuild/clean a carb, I give great step by step instructions to over haul a carb, and most members has had great luck in following them. and they got their atvs running like new again. you can find them on ebay, DON'T BUY THESE PARTS FROM HONDA FOR OEM !, the cost will kick ya in the nutz for what one piece will cost you, other than buying the whole kit from ebay :).
I agree with Shade. There are some very good trx 300fw carb rebuild videos on youtube. Look for the one by D. Ray. Make sure your kit is for the correct year model.
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