Quick question

I'm just sittin here wondering about my yz 125. I harescramble with it and some fun track but I got to thinking; is 40:1 enough? Should I do 32:1? What are the benefits of em both?

I'm just sittin here wondering about my yz 125. I harescramble with it and some fun track but I got to thinking; is 40:1 enough? Should I do 32:1? What are the benefits of em both?

40:1 is plenty if you use a quality oil. The benefits are that you will use less oil per tank of gas. (Less expensive)

What will make my top end last longer?

Yamaha recommends 32:1. I see absolutely no reason to deviate from that. Going 40:1 saves you almost no money... Literally.

32:1 will save some wear on your top end, but in a 125, a top end just isn't going to last that long, no matter what.

24:1 with Walmart supertech. More horsepower, better protection, less money.

Hmm. Well I know it is off topic, but how long do U guys think I can stretch a 125 top end I. I don't race and just play on it with some trails and light track. The top end now has 3 races from the previous owner. Still strong compression. When should look to replace it?

I looked very quickly in the Yamaha manual and could not find a time frame that Yamaha suggests. It depends on your riding style and conditions. Try to find what Yamaha recommends. I can tell you this; leaving a piston in too long is no fun. The skirt will break off (especially on a stock piston) and ruin your engine.

When you do replace the top end, you will want a Wiseco. They are a forged piston. They are stronger and much more durable.

When i rode a 125, i changed the ring every 10 hours and the piston every 20-30 depending on if it was race season or not.

If you're not sure, change it!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now