Kawi2strokes.com Forum

Does anyone have a new 72 mm wiseco piston they can measure for me.
would like to know the width of one of the new ones.

I have a new +.080'' in front of me but I am drinking wine....... (Joke, that'll be 73mm.... close, but...)

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.

Wössner, and I believe Wiseco too, currently make the pistons so that when installed in a bore that's exact size, in this case, 72.000 mm, or 2.8346 inches, the clearance will be as specified. You can verify that with Wiseco, but a 72mm Wössner will be 2.8319 inches at it's largest place across the skirts. Depending on how old the piston you have is, it may or may not have been made that way.

Edited to correct stupid mistake.

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If it surges, that's normal, upshift.

Thanks Jim, that's what I wanted to know

the one that was in there was 71.8312. quite a bit different

Error! Sorry, I just noticed I pulled the usual mixup of mm and inches!

72mm pistons are 0.0027" smaller, not 0.0027 mm smaller! So a 72mm bore is 2.8346", and the piston should be 2.8319". Your piston appears to be in good shape, at only 0.0007 worn. You need to measure the bore in several places to see if your clearance is really too big or not. I'm going to correct my post above so I don't goof someone up later!

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If it surges, that's normal, upshift.

thanks for that clarification, I thought something didn't look right

I will have to re-measure when I get home tonight. played hooky yesterday and got to play in the shop all day
but at work today

Lol, well now you got me thinking. Maybe I got it mixed up too.

piston might be 71.828

I remember something.828 on the piston and I figured .007 clearance

i'll have re-measure when I get home. this is going to bug me all day!

ok, so i re-measured.

the bore is 2.8346

piston is 2.8265

thats about .008 thou clearance on this old wiseco L ring piston

I measured up and down , left and right on the cylinder.

there is about .0005 out of round.

That'll be noisy alright. You measured across the skirt, around 1/2" up from the bottom, right?

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If it surges, that's normal, upshift.