Goldeneyes

Hey SEG, or anyone else who knows:

I did a rebuild on a rotax 503 fan cooled, out of a 1995 Formula SL
I haven't done the full break in yet, but I did run it for about 20 minutes after the rebuild at varying RPMS (not full out.)

Anyway, compression is just under 130LBS when it's hot. Is this acceptable? We only honed the cylinders, put all new pistons and rings in, new gaskets on everything (including crank.)
Haven't done a leakdown test.

-Stu

SnowRida

125-130 should be good. Sounds like you were successful.

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smallengineguy

That's way good! Should be fine. Run the first tank of fuel with extra oil in it, then you'll be set.

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Goldeneyes

Ok I wasn't sure cause a Seadoo I bought with a 720CC motor in it had 153PSI on each side. Does the compression go up with bigger engine sizes?

smallengineguy

Depends on the bore/stroke/piston kind.

__________________
1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month!
1993 Ski Doo Mach Z 780 triple
2001 Ski Doo Mini Z



Evergreen Valley Snowmobile Club Webmaster

If I'm not home, CHECK THE TRAILS!

smallengineguy

__________________
1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month!
1993 Ski Doo Mach Z 780 triple
2001 Ski Doo Mini Z



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If I'm not home, CHECK THE TRAILS!

MackmxzX

sounds like you did a good rebuild! SEG APPROVED! congrats