OK, I cant seem to start my bayou 300 in neutral, with the push button start. The only way I can get it started is pushing it and jumping the starter solenoid, or getting pull started from another quad. Does that mean the piston ring is too worn out? I dont think it has enough compression to start by itself, it just cranks over and wont start. It smokes pretty bad, its over 15 years old. I plan on rebuilding it, just seeing if this is the main problem? Thanks

 

that is definitely a good indicator that the compression is gone. The first thing you notice is it won't start.

 

OK, cool. What should I do for a basic rebuild? Just ring and gaskets? Maybe clean up the head if there are any rough spots? I know you can hurt flow with porting, if done wrong. Thanks

Dave

And if I need a new piston, I think Ill bump up compression a little, and also rejet.

 

Probably should bore it an put a slighty bigger piston in. Have the head checked for guide prob and mayve grind valves and seats.

A lot of quads loose compression because:
1. the air filter leaks dirt into the eng, airfilter was always dirty, airfilter was missing. Super bad.
2. oil wasn't changed, and/or engine sat too ong between runs. Very bad.
3. riders gave it a lot of gas and/or revved it cold. Just bad.

A worn piston will rock too much and wear the new rings out. Check that and also look for scoring.

 

they sell cylinder sleeves for the 300 bayou - i dont know what year you have but dennis kirk offers them. You can change the sleeve and go back with original bore and std size piston.

 

You can start it by jumping the starter solinoid? Look for bad gound connections in the starting cicuit, and have someone do a load test on the battery.