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WFOracer

Is the 450 doomed??

11 posts in this topic

I really think your looking to far into this. They are two completely different worlds. the R1 is a four cylinder, and the 450...its one. Yamaha , MOST LIKELY wont ditch the genesis head because it has proven to be reliable, just as it was in the Ford SHO, its what has made Yamaha popular. The only way they will scratch it is if they can come up with something even more bulletproof...which is always another option, because those crazy japaneese designers are pretty dam smart

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The 2006 R1 had 5 valves per cylinder....the 2007 has 4. I was looking at it from a per cylinder perspective.

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What does it matter? An extra valve does not create horsepower , so what is your point?

but the extra valve proves to provide the yamahas with a more reliable head...the extra valve allows the rest to be smaller which is less moving weight in the engine

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but the extra valve proves to provide the yamahas with a more reliable head...the extra valve allows the rest to be smaller which is less moving weight in the engine

Thanks, couldn't say it better myself! :devil:

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My O3 450 Has Broke The Center Case On Kickback Twice, Any Suggestions Greatly Appreciated, Also Will Wrf Electric Left Side Stuff Allow Me To Convert, I Am Old And Fat Tired Of Kicking The Beast.

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My first suggestion would be to post a new thread with your question, so that this thread stays on topic.

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but the extra valve proves to provide the yamahas with a more reliable head...the extra valve allows the rest to be smaller which is less moving weight in the engine
The 5 valve head does not make the engine more reliable, but it does offer performance advantages in terms of gas dynamics within the combustion chamber, and it does reduce the weight of the individual valve train components.

The fact is that the intakes in the CRF250R are about the same size, or smaller, than the intakes in the YZ450F. If smaller lighter valves with less spring pressure was all that there was to it, then the valves in the CRF250 should last as long as those in the YZ450. Do they?

What makes Yamaha valves more reliable than many other brands is the oldest, simplest formula there is; a better executed design using superior materials and fit. It's not rocket science.

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