Who makes the best 450 top end kits?

I have always gone to Pro Circuit for my KX's and my wife's Banshee. Vertex pistons have always been bullet proof for me. I was really hard on two stroke motors and would usually run them till they kicked like a 450 :D

YZF's are a totally different monster though. What do you guys think. I wanna do my top end before I hit Glamis this halloween. My bike has a CRAP-LOAD of hours on it and a whole season of sand from last year. :D

Personally, I would use only OEM parts. I have heard stories about aftermarket pistons in yamaha 4 stroke motors.

Is anyone running an aftermarket piston :D

Is anyone running an aftermarket piston :D

I hear many people say to use only OEM. I also hear people say to use Wiseco. I personally installed a Wiseco topend and was very pleased. This is what I've read, so guys, don't start beating me up. The Wiseco is forged and it has a slightly larger clearance. The reason being, they tend to expand slightly more from the heat. The end result is supposed to be a better ring seal when at optimal temperature. I'm not claiming this at all, but just what I read. Anyway, I did see a slight increase in power with my bike after the rebuild, and I didn't have any problems at all.

Personally, I would use only OEM parts. I have heard stories about aftermarket pistons in yamaha 4 stroke motors.

Ditto that. Go OEM.

Ditto that. Go OEM.

Yeah I think so :D

I would check with the crf guys,lol

I've got a Wiseco in now, but dont have enough time on it to give it the stamp of approval yet. It does not 'slap around' in the cylinder as I've heard some people say and it has no trouble making big power.

I would check with the crf guys,lol

Man, I tell ya, why is it when anybody asks a decent question someone comes along and instead of contribuiting to the topic starts to bash another brand? Hummmmm. Can't we all just get along and give some good advice? :D

I put a Wiseco in a few months and its been working well. No issues, knock on wood :D !

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