Honda Fourtrax 300 wont idle

[deerefan]

Have you checked the bowl under the fuel petcock? Has a problem like this and it was full of grit/dirt. Simply unscrews. I clean it about once a year now. Also, check your air filter thoroughly. Mine looked clean on the outside but had begun to disintegrate on the inside, clogging air flow. Also check the air intake tube along with all vent tubes for the dirt dauber nests as mentioned above. I have also had good luck with Seafoam in clearing clogged jets on small engines. I have a 97 300 4x4 we use everyday, twice a day, to feed horses and for other farm chores. Motor has never been rebuilt but we just had a whole new rear end assembly, including rear brake system and axles, replaced. Cost almost 2k, but way cheaper than a new one. I also have a 2000 300EX for fun, no issues at all, just normal maintenance. The Honda 300 was, imho, the best atv built. They do not seem to build them as tough now.

 

[dfkrug]

I've replaced the carb last year, new petcock, took the carb apart and it didn't appear
to be gunked up...neither did the old petcock but went ahead and replaced it anyways.

Another big fan of the 88-2000 TRX300FW Fourtrax 4x4 here.

My main quad is a 96, and I just completed major work on a 93.

Anyway, since you bought a new OEM carb ($$!), your jets are prob fine. My bet is a vacuum leak at the
boot betw the carb and engine, or the cold-start enrichener valve. Try this: get the quad started
and idling as good as you can. If that means cranking in the idle thumbscrew on the side of the
carb, do so. This just holds the throttle open a bit. Then spray some carb cleaner on the
intake boot and where the cold-start cable enters the carb. If any change in RPM, you have
a vacuum leak. Usually an easy fix.

IMO, the only 2 issues with this quad are: a steel tank that rusts, and the 4x4 is always-on.

 

[sal64]

i had same thing with my honda sk350, like dfkrug said its the steel fuel tank, i took mine off and put a law mower plastick tank on it then i took the carb off cleaned it good put some seafome in it and so far no more problems

 

[Winmac]

I'm thinking That bike has a cable on the enriching valve( choke) it could be hanging up flooding it out at idle.

 

[RollingsFarms]

I think I finally got it fixed. After trying all of your suggestions I decided to dump a bottle (the whole bottle) of stp carb cleaner in it and then ran the atv HARD for a couple hours doing stuff around the farm. I think this cleared it up, only problem now is its idling too high and I need to turn the screw on the carb down some.

 

[dfkrug]

To fans of this fine quad, Honda is now making more of the seats, so you can buy a complete
new one, cover, carcass, and foam, all for under $100.