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08 Piston Rings

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Does the 08 high compression piston have 2 or 3 rings? Also, how many rings does the regular 12:5:1 piston have?

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They all have 2 compression and an oil ring stock.

Here's a hot tip... you only need to run the top compression ring in the stock pistons.

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They all have 2 compression and an oil ring stock.

Here's a hot tip... you only need to run the top compression ring in the stock pistons.

why is that?why do they give you two then ...

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Williams, can you only run the top one o CP piston? I run a CP YZ piston in my 07 Wr 250F.

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They all have 2 compression and an oil ring stock.

Here's a hot tip... you only need to run the top compression ring in the stock pistons.

More info please! What do you gain by doing this?

Chris

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If all you do is trail ride, leave them both in there.

But if you do any type of racing, you'll have a lot less friction with only the top compression ring. It's worth almost .2 of a HP in the upper RPM ranges.

You guys do realise what I mean by the "compression" rings right?

The oil ring set has 2 rings and a "spring" ring. don't mess with the oil ring set.

You can do this to any bike or piston.

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Is it safe? Would the piston not wear faster with just the 1 comp ring? And would the 1 comp ring not wear faster than normal?

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So the middle ring is unnecessary? In the long run do you lose some reliability and/or longevity?

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I remember on my YZ 125 it also only ran 1 ring and I was told it only needed 1 from the yamaha guys. they said there was less drag therfore quicker revving and more power, but I also had to change the ring often as it wore quite fast. they also told me to change the piston often too.

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So the middle ring is unnecessary? In the long run do you lose some reliability and/or longevity?

When I did your motor I thought I told you about this?

Yamaha is the only one that runs 2 compression rings in their 250f's. It doesn't lose any reliabilty at all.

Just run the top ring, and keep the oil ring assembly of course.

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just for my refrence what is stock compression?

Depends what year? 13.5 = '08, '09 13.1= '07, '06, '05

Are you asking about PSI? You don't check that on a 4strk because of decompressor.

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You may have, I am almost 100% positive I have short term memory loss. I don't remember if you did or not but next time I take it apart it's losing a ring for sure.

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