I have 1991 350L Trail Boss. I was having problems keeping it running after it starts. I thought maybe the plug and carberator were at issue so I changed the plug (probably needed anyway) and took the carb off and cleaned it.

My problem did not get any better and if anything it is now worse.

What I need to do is start it and it does start normally. Then keep the idle up w/the throttle until it warms completly up. I tried making some adjustments but nothing helps until it is totally warmed up. This takes quite a while. If it was a few seconds, I would not care but it is really more like 4-5 minutes. After this amount of time the ATV runs GREAT, very peppy no flat spots. I am confucsed. Should I be thinking a head issue?

Thanks,
Bill

 

I was hoping for a reply/advise before I posted my next step. I am thinking it is a choke chamber issue. Tonight I am pulling the carb again. I will take the whole thing apart and clean better. I will use my air compressor to blow out the tiny passages. When I reassemble I will be very carefull in my adjustment of the choke cable. Maybe it is not seating completely.

Thats all I got.
Bill

 

is the spark plug wet? did you make sure the idle circuit is clean as well as the piolet jet is clear? these are what controls idle and throttle up too 1/4 throttle. air screw should be around 1 1/2 half turns out. if by keeping the enrichern up(pulled) keeps it running better then its a lack of gas or too much air and the reverse ifit hurts the running.

 

The idle circuit and pilot jet are going to be my focus when cleaning. There just must be something in there I have not found.I have tried every air screw setting from 1/2 turn to 1 or 1-1/2 to 2....... Book said I could go from 1/2 to 3. 1-1/4 seems to idle best when itis running........ Darn thing runs great when it is all warmed up. UGH
Thanks!

 

yea 1 1/4 sounds about right.

 

I got it. Combination of blowing out all passages and reducing spring tension on choke.

Thanks!
Bill