Have a 110cc that has been running great.

Now it just doesn't want to fire up. It would fire up 1 or 2 times out the 30+ times I've tried to start it. It would run for a bit then die and no go after that.

It has a recently new carb on it. I take it all apart again and make sure it's clean. There is gas on the plug. I have a newer spark plug in it. It always has a very strong spark when testing.

I've got rid of the kill box, etc.

I've tried 2 different CDI boxes. I checked the valve clearance and was in the .002 range. I adjusted them closer to .005/.006 and tried that. NOTHING.

Where do I go from here?

 

check compression

 

Have you tried to take the carb back to factory settings?

 

What should the compression be for this engine? Just turning the engine over by hand with my finger over the spark plug hole doesn't create much force. I'm going to grab a compression gauge and see what it is.

 

I would say minimum 80-90. Anything lower, it won't combust. You should be reading 130+. Is this a two or four stroke?

 

four stroke

 

Yes, I did do that.

 

You might get off easy if your valve adjustment is off, try to adjust that first. I do not know the measurements for this model tho. There is probably a general setting to get close.

 

Yes. I checked the valve clearance and they were .002 range. I adjusted them closer to .005/.006 and tried that, but no change. I might tighten them up a bit more again.

 

Ok, cool. Now try and pull compression.