I checked the compression of my 1994 Seadoo XP using the technique described in this forum. The readings were 120 rear, 150 front.
The real question is whether or not the 30lb. difference between cylinders is enough to warrant a top end rebuild. I have read on the forum that a maximum of 15% difference is recommended and my delta is greater than that. Most opinions I found recommend they be within 5% of each other.
I am curious to know what symptoms a motor shows when there is a difference of more than 15%. Lower top speed? Less acceleration? Hard starting? And how does running a difference in compression between cylinders contribute to component failure. My intuition tells me that the good cylinder is doing more work and therefore will experiences more wear and abuse. I would expect the motor to produce less power over time as the good cylinder wears out.
My knowledge of these engines is very limited but growing thanks to the forum. I would like to know others opinions on why it is critical to maintain near equal compression on both cylinders and what happens when there is a substantial difference.
For the $400 it will cost me, should I go ahead and have a top end rebuild done?
Any opinions would be appreciated.
Mike.
The real question is whether or not the 30lb. difference between cylinders is enough to warrant a top end rebuild. I have read on the forum that a maximum of 15% difference is recommended and my delta is greater than that. Most opinions I found recommend they be within 5% of each other.
I am curious to know what symptoms a motor shows when there is a difference of more than 15%. Lower top speed? Less acceleration? Hard starting? And how does running a difference in compression between cylinders contribute to component failure. My intuition tells me that the good cylinder is doing more work and therefore will experiences more wear and abuse. I would expect the motor to produce less power over time as the good cylinder wears out.
My knowledge of these engines is very limited but growing thanks to the forum. I would like to know others opinions on why it is critical to maintain near equal compression on both cylinders and what happens when there is a substantial difference.
For the $400 it will cost me, should I go ahead and have a top end rebuild done?
Any opinions would be appreciated.
Mike.
