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High compression

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I'm doing a top end rebuild soon so I was wondering why not throw a high compression piston in my 2004 wr450f. I heard these engines are bullet proof, would a high compression piston screw anything up and lesson the durability.... could I go 10 000 mile on the stock crank with the hc piston. Will I get 2,000 miles out of the hc piston? Just wondering if it's worth the extra 20 dollars  I run 93 octane so fuel should be fine 

 

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Probably would be fine. I have run many 13:5 to 1 480cc big bores in my WR’s but 07’ up. So I don’t know that much on the 04’s. I know they have the upgraded starter gears or so from the problem 03’s. Maybe someone with direct experience can chime in. 

That is not too much compression in my opinion. There are many street bikes that run 13:5 pistons and last for miles and miles and miles. 

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I use to run CP 13.5s in my first gen YZ450's. Never had any issues with them even on pump gas.

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5 hours ago, SteveThe Snakes said:

Stay away from Weisco.  

Try to get a three ring piston if you can. Like a CP or a JE if they make them. 

Is there a reason 1 ring is bad?

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How do I know if my piston rings are worn out? ... I might have to go with wiseco they are the only piston maker with 04 parts I could find 

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Ok so if I put in 13.5, i came expect the same life out of my crank? Becasue I found a 13.5 on rocky mountain 

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7 minutes ago, SteveThe Snakes said:

The clearance they state is what Yamaha states to replace the piston. 

If you have the cylinder machined for whatever piston to the proper clearance then it shouldn't matter 

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8 minutes ago, UPSWR450 said:

If you have the cylinder machined for whatever piston to the proper clearance then it shouldn't matter 

Um they quote like .003 Yamaha quotes about half of that so no. Wiseco hopes and says the piston grows when it gets hot then it fits well. I prefer a better design with a tighter clearance. 

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1 minute ago, SteveThe Snakes said:

Um they quote like .003 Yamaha quotes about half of that so no. Wiseco hopes and says the piston grows when it gets hot then it fits well. I prefer a better design with a tighter clearance. 

I have a weisco in my cr500 and all is well. Any difference in a 4stroke piston vs 2t when it comes to clearances?

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