Honda ATV Forum banner

FourTrax 300: Running rough after filter change

6053 Views 10 Replies 5 Participants Last post by  ostrx250
I recently changed the air filter on my '90 300. Since the change, the motor is running very rough, I have to choke it almost all the way. It won't run with the choke off.

Seems like an obvious fuel / air mixture problem. Advice? I saturated the filter in oil, although I used chainsaw oil, not air filter oil (couldn't find any and this was recommended as a substitute).

Any input greatly appreciated.
1 - 4 of 11 Posts
Welcome to the forums. Since the problem occurred after you cleaned the filter and put the chainsaw oil on it, I would take the filter off and see if it runs OK, without the choke. If so, I would clean the filter again and use regular filter oil. I would have thought that chainsaw bar oil would work, too, but maybe it won't.
Blade oil. Thanks for the input...will try with the filter off.
Yeah, I bet it's too thick.
yes..bar oil is way to thick for air fliters..it can't breath hardley at all..40w oil is about right..anything thicker than that.will cause your air problem.
You can use 80W-90W. Look in your 350 Foreman service manual, it calls for 80W-90W on the filter element.

I don't know how thick chainsaw bar oil is, but it's thicker than 80W-90W.
I recently changed the air filter on my '90 300. Since the change, the motor is running very rough, I have to choke it almost all the way. It won't run with the choke off.

Seems like an obvious fuel / air mixture problem. Advice? I saturated the filter in oil, although I used chainsaw oil, not air filter oil (couldn't find any and this was recommended as a substitute).

Any input greatly appreciated.
I'm having the same issue with a 93 300 4trax 4x4.

Now, clearly I need to explain a little history about mine.

1- I had a blast of a ride out in the country on some trails and feilds, to my surprise some of the mud quickly turned into a pond. So I was 2-3' deep in h2o. My natural 4x4 instinct kicked in and said DON'T KILL THE GAS! h2o filled up to this level isn't good.

2- I've replaced the air filter, oil filter and oil. All using genuine honda parts from my local dealer.

3- Still having to choke it all the way for it to run. I can't let the choke off or sit idling at all or it'll die for sure. This maybe where I need a :r_c: and let the pro's take care of it, unless someone can point me in the right direction for treatment.

Thanks to the 4x4 god's for allowing us to have a forum like this one!

3gig.
Welcome to the forums. I would try taking the carb off and giving it a good cleaning. Take the top off of the carb, too, and make sure there isn't any water inside the vacuum piston.
1 - 4 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top