12-09-2012, 01:32 PM #1
- Join Date
- Dec 2012
How Bad is a High Compression (180) on a 4 TEC engine
I'm thinking of buying a 2003 Seadoo Sportster 4 TEC and it looks to be in good shape, but when I had a pre-buy inspection done, the compressions came out 160, 160, 180! The mechanics were concerned about the 180. What's the problem and how bad could this be?
12-09-2012, 01:37 PM #2
I believe the N/A motors should be at 195lbs.? So 160 would be low. Also a 10% seperation is OK. Anymore I dig deeper.
SO 10% of 180 is 18psi. Your at 20psi. difference from the other cylinders. Over 10% and nowhere near the 195lbs I believe they are supposed to be.
12-09-2012, 01:59 PM #3
You will be fine you may just have what we call a happy compression gauge
12-09-2012, 02:07 PM #4
12-09-2012, 08:51 PM #5
12-09-2012, 08:53 PM #6
Also how long has the engine been sitting? Try doing a wet compression test. Put a bit of oil in each cylinder. If the compression comes up and the engine has been sitting for a bit then you should be fine. If the boat has been run recently and the compression is still that low but comes up with a wet test then you have rings and cylinder issues
12-12-2012, 08:51 AM #7
leak down test the biotch. Could be a leaky valve, ring or gasket. Blow by is no good. I'd never touch anything that bleeds compression.
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