I found the timming marks at got my timming set but my kids raptor still wont start. I m getting fuel and spark. It Just wont pop off and run any ideas..
Sorry about my other post. I am a father of 4 boys and cnt afford to luxery of buying manuales or taking it to the shop. And my boys hound me everyday "Daddy did you get our 4-wheeler fixed yet?? We want to ride."

Thank you for any advise.

 

Have you tried tradebit.com for a manual?
Usually under $10 for most atv ones and if you want to avoid the stealer they are worth much more then that

 

thank you. That I can afford.
Just to let everyone know I replaced the piston,rings and cylinder. I have the gap in the rings 180 deg. apart and the arrow on the piston faceing down. Is that correct?
And does anyone know what the compression is suppose to be. Iam going to buy a compression gageand check it. that is the only thing I can think of to do.

 

well I went and bought a compression tester and their is no compression.. Why??

 

Did you check the valves too? Hear any air leaking into the exhaust or carb while you turn it over?
If its like the badger 80 motor the Minimum comp spec is 142 lbs and the normal is @ 175 lbs

I had 124 and the thing would not fire. So I did both the valves and the cylinder. If in doubt about the valves, pull the head, invert it in a vice and pour gas in the combustion chamber and see if it leaks past the valves.

Also the cylinder, did you have a machine shop measure it to see how worn it is? Or is it a new cylinder, piston and rings? Sounds like you did it right. Will it fire if you push start it? How about with your battery charger on it to bring the cranking rpm up a bit with some extra volts?
On a single cylinder you can't afford to lose much compression.

I had a machine shop measure my cylinder, it was .003 within the max spec, so the machinist talked me out of boring it oversized. Problem was once I bought the piston and he honed it, it still had a trace of the rust area in the side of the bore. Only maybe .001 deep but you could see it and feel it with your finger. It took @ 10 hours for the rings to seat up b4 the machine would start on the starter. Before we had to push start it.

I would try to push start yours in 2nd gear and see if it will start.

 

I would try to push start yours in 2nd gear and see if it will start.

It's a CVT...

Sir, I understand the $$ problem...I don't have any either.
But you may need that manual.

 

"Its a cvt ..."
Sorry I can't be familiar with them all.

To make up for my transgressions here is a manual for $4
Yamaha Raptor 50 2003 to 2004 Service Manual - Download Technical

there are several others under $10 just make sure you are getting the service and repair manual and not a owners manual.
If it was $50 it would still be the best money you can spend on the bike, your time is worth something.

Also since you have no compression, I assume that means 10 psi or less, did yu try squirting some oil in the cylinder to see if that has any effect. If it does it points towards rings, if not then valves are more likely the culprit.