110 ATV runs at low RPM

[Rick Cruz]

I have a 110 ATV which started fine yesterday. Today I go to start it and it only starts with the throttle wide open and then runs at low RPM, Unit is getting spark. Would apprecate any help I could get. Unit is a Chinese ATV.

[Frank Angerano]

I would double check that the choke is working properly. 

Then I would assume that the carburetor is loosing its fuel.  Where it’s going is the question.   

You could also have a crack in the rubber boot connecting the carburetor to the engine.   

[Andy Fell]

Quote

 

some small atv  have a speed limiter  for when youths are operating  has this become active ?

[Rick Cruz]

No rev limiter except the screw on the throttle. I have painted a mark where it's supposed to be and it 's still at that mark. This all has me wondering if weak spark could cause this issue.

[Frank Angerano]

I’ve had one of these bikes. Aside from the obvious things I pointed out in my previous post one thing I had to constantly do was change the plug.  Or at least pull it and clean it. You jogged my memory on this. 

Try this. Go buy two spark plugs.  Run the bike as it is and the next day see what happens when you go to start it.  If it does not start right up swap the plug for a new one and see if it starts up. 

Next day right out of the gate put a new plug in again and see if it starts right up.  If so the plug is getting fouled a bit lessening the spark.  Why ??? Could only be a few reasons.... 

These engines are not really well built and oil gets into the head though valve seals or rings etc.  Mine always blew a little blue smoke out of the exhaust. I was convinced oil was getting into the head.  Also I leaned out the carburetor a little and it helped but not too much where the engine ran like crap.

Maybe you can start there and see if the problem gets a little better with adjusting the fuel air screw first.