piston clearance Mitaka (new edition)

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dirk
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piston clearance Mitaka (new edition)

Post by dirk »

hello everyone

I need new pistons.
i want to buy new Mitaka piston.
these are available from 55,94mm - 55,97mm.
what is the best piston clearance?
is ok 0.05mm or 0.06mm better?

Regards
Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
Luders
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Re: piston clearance Mitaka (new edition)

Post by Luders »

I always get mine honed to 0.05
dirk
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Re: piston clearance Mitaka (new edition)

Post by dirk »

Thanks for the answer.
i asked because at Yamaha (2MA) is 0.05mm too tight (with ProX Piston).
the cast iron liners need to 0,065mm.

pistons are ordered, and I hope the KR is ready for use again this month!


Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
Luders
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Re: piston clearance Mitaka (new edition)

Post by Luders »

Ah I see the difference, 0.05 on the nicasil plating is good and what I always request.
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JanBros
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Re: piston clearance Mitaka (new edition)

Post by JanBros »

dirk wrote: the cast iron liners need to 0,065mm.
normaly clearance depends on the piston no ? forged vs cast. forged needs slightly bigger.
My ultimate goal is to die young as late as possible !
KR-1R
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Re: piston clearance Mitaka (new edition)

Post by KR-1R »

and where on the piston do you measure? of course front to back but
do you average the clearance because between crown, gudgeon and skirt...
the difference between those alone is 0.05mm let alone from empirical measurement (repeatability)
dirk
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Re: piston clearance Mitaka (new edition)

Post by dirk »

good morning

i measure it at 25 mm from the skirt end.
the Yamaha manual says between 0.05 and 0,055 mm.
this is too tight with ProX!
i have tried it twice....
with Yamaha Piston it works.
perhaps PROX Piston expand more?
both are cast piston.
at the RG500 is 0,065 - 0,075 mm standard.

Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
geezagillard
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Re: piston clearance Mitaka (new edition)

Post by geezagillard »

Don't forget the RG400/500 have iron liners so assume more clearance?
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