I went riding with my friend today and his Recon is not idling right. It will idle right for a while and then start speeding up for no apparant reason and then it will slow down to normal and then cycle back at no regular interval. He has only tried adjusting the idle stop screw on the side of the carb. Does anyone have an explanation as to what might cause this cycling and how to correct it?

 

I was hoping that someone could help me with this if they saw it. I initially sent it right before Christmas and I was afraid that few noticed it.

 

clean the carb

 

bdcothran-What year is this Recon? Has it had the first service from the dealer? My wife has a 1999 and it would not idle at all when cold. After the dealer serviced it the first time, (I told them of the problem) the problem was fixed.

Sounds like you might have a leak around the carb/intake area. This will cause this type of problem sometimes. Check to make sure all the connections in this area are tight.. Hope this helps....

 

It is a 99 and he bought it in April. He did not take it back to the dealer. I wondered about an air leak. I made a quick check in the field and found no obvious leak. I was wondering if the needle jet might be set in the wrong notch. It does not seem to help when it warms up.

 

Don't really think that the needle setting would cause the eratic idle if it is doing this at idle. I still think there is a air leak somewhere.

I'll bet that it's running lean for some reason. Perhaps it's time to visit the dealer. Good luck.

 

you could have a vaccum leak or the idle "mixture" screw may need to be adjusted.
If the ATV is not old, cleaning may not be the answer. first things first.

Here's what you can do:

Step 1, to find a leak, get some carb cleaner. With the engine running.. spray it around the intake where air can leak inside, if the idle speed changes with the spraying, you have a leak. (be careful, the spray is flamable)you do not need to "drown it with spray" any leak will be sucked in and idle speed will change.

Step 2, If you haven't had it at the dealer for first service/set-up AND it's cold natured.. take the top of the carb off and set the needle one click richer at a time. (thats moving the clip down one notch on the needle) and see if it improves the cold nature situation. This may also help the idle.

Step 3, look for the Idle mixture screw. This is NOT the idle speed screw. The mixture screw is sometimes hard to find. rule of thumb is to turn in the screw till the engine begins to miss/idle poorly, then back it out till you get your best idle. Some add 1/4 to 1/2 more out after best idle.

I hope this helps. If not, take to a professional.