I finally got the quad to a point where it will start and idle.

I did this by turning the mixture screw almost all the way in (air box off).

I thought I had it running right until I got on it and tried to move it. If I give it to much throttle it just bogs. Could turning in the screw too far damage the engine?





I did a search on this site and found it could be the crankcase seals. I have changed them on snowmobile engines but not on an atv. I know on my sled I can test them with carb cleaner. Is it possible to do the same test on the atv or are they covered? How big of a job is it to change the seals?

I need to have it running in 14 days!
Not to mention it is in the basement and I can only work on it after 9 PM.

 

Did you clean the carb? Sounds like a plugged main jet.

 

I cleaned it twice. I made sure i can see through the jet.
It looks pretty good.

There is no air cleaner on the carb. I am sure it would restrict airflow and make it richer but I can't imagine it would make that much of a difference.


I also removed the electric choke and tested it.
I even dropped the clip on the jet needle to try and make it richer.
I looked at the reeds. They looked fine.
I sprayed carb cleaner at where I think the crankcase seals are located and I didn't notice an rpm drop.

I am stumped.

 

Hmmm... How about ignition? I know a few has fixxed similiar problems by pulling the flywheel and sand/clean the stator/flywheel.
The pipe plugged?

 

I didnt mention that there is no battery in it.

Does that make a difference????

 

The exhaust looked okay. I can take it off and try reving the engine.

Spark looked okay but it wont hurt to check.

I am starting to question the compression again. Although it does idle and rev a little . My gauge is shot. I will pick one up tomorrow.

I think I will try a new plug.

 

The compression will tell alot.

 

I ran to Harbor Freight and grabbed a new compression tester.
The PSI is either 65 or 95. Let me explain, it comes with an adapter for 14 MM. If I use the adapter it measures 65 PSI. Withough the adapter, it still treads into the plug hole but it measures 95.
I assume I need the adapter and the compression is 65 PSI.

This is with new rings and having the cylinder honed.

I assume this means I need a new top end??
Ever use the $99 ebay kits?

 

Well, the rings may not be seated but I never put rings in w/o a new piston. That's my choice. I know some like to re-ring.
Either way, yes, it's too low. Get yourself a nice stock piston/rings, gaskets and such from your dealer.
I don't use wiseco pistons unless I have to.
Did the guy that honed it measure the piston to cyl wall clearance?