I recently bought a js550 that has a pjs head on it, after compression testing it showed 175/75. It looks like a head gasket and that might be it but is there any thing else to check while I have the head pulled off? The cylinder walls don’t have any scoring and still show hone marks. Thanks for the help!
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Js550 compression issue
- Thread starter crazymike
- Start date
That was it thanks!Stuck piston ring.
My pleasure crazy mike.
The old semi-abused 550s tend to carbon/varnish up (I still have no idea what these people burn for 40:1 oil??)
Anyhoo, once a piston ring sticks to the piston & no longer free floats you get that lop-sided cranking speed & difficult/impossible starts as well.
Little Berryman B-12,clean the deposits from ring grooves/rings, lube with a decent marine approved two-stroke oil & back in business.
The old semi-abused 550s tend to carbon/varnish up (I still have no idea what these people burn for 40:1 oil??)
Anyhoo, once a piston ring sticks to the piston & no longer free floats you get that lop-sided cranking speed & difficult/impossible starts as well.
Little Berryman B-12,clean the deposits from ring grooves/rings, lube with a decent marine approved two-stroke oil & back in business.
Any tips on getting the head back on? Just a little lube and pinch and work the pistons in?My pleasure crazy mike.
The old semi-abused 550s tend to carbon/varnish up (I still have no idea what these people burn for 40:1 oil??)
Anyhoo, once a piston ring sticks to the piston & no longer free floats you get that lop-sided cranking speed & difficult/impossible starts as well.
Little Berryman B-12,clean the deposits from ring grooves/rings, lube with a decent marine approved two-stroke oil & back in business.
Thank you for the advice!line up the rings with the locating dowels,pinch the rings and lower cylinder.start with front piston and then do rear one.