-
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
Help needed with compression
- Thread starter seadooman
- Start date
- Status
crf4501985
New Member
The rings are stuck most likely. Spray some penetrating oil in the cylinders and let is soak then take another reading. Your readings will very between a cold and warm motor, and while you are taking a reading make sure you have only one plug removed at a time and you hold the throttle wide open.
crf4501985
New Member
Sounds like it's time for a top end rebuild. How many hours are on it?
Don't laugh
Don't laugh at this:rofl:. It works, I've done it on 4 cars 4 motorcycles and a few lawnmovers. An old helicopter tech had me do this and promised to buy me a new engine for my 66 Mustange if it damaged my engine. Drove it for 6 years no smoking. #3 cylinder would smoke about 5 min. then oil foul the plug. He had me go buy some Bon-ami cleaner and some K-1. He mixed 1.5 teaspoons with a cup of K-1. Shake and pour it down the carb a little at a time with rpms up. Had to keep it running, boy did it smoke. 10 min. later compression was with in specs. He told me that if the helicopter rings didn't seat in x amount of time that it had to be tore down again, per FAA. Of course smaller engines use less more cylinders use more, do at your own risk. Made many old cars pass the state emission test. I still have a can in the shop. I have not tried it on a PWC yet. Good luck
Don't laugh at this:rofl:. It works, I've done it on 4 cars 4 motorcycles and a few lawnmovers. An old helicopter tech had me do this and promised to buy me a new engine for my 66 Mustange if it damaged my engine. Drove it for 6 years no smoking. #3 cylinder would smoke about 5 min. then oil foul the plug. He had me go buy some Bon-ami cleaner and some K-1. He mixed 1.5 teaspoons with a cup of K-1. Shake and pour it down the carb a little at a time with rpms up. Had to keep it running, boy did it smoke. 10 min. later compression was with in specs. He told me that if the helicopter rings didn't seat in x amount of time that it had to be tore down again, per FAA. Of course smaller engines use less more cylinders use more, do at your own risk. Made many old cars pass the state emission test. I still have a can in the shop. I have not tried it on a PWC yet. Good luck
crf4501985
New Member
If both cylinders read 90PSI then those we're 104 very hard hours! You running seadoo synthetic oil? Sounds like a rebuild is in order.
i dont know because i just got them from someone that had them in a warehouse. so all i have to do is replace the pistons and rings right. right now its pouring fuel mixture out of the exhaust. my guess is that it is not burning it all and is getting rid of it throught the exhaust.
Here is the correct info on a compression test. It covers all the basics.
To test compression, remove both spark plugs. Place spark plug caps on the plug cap studs near the cylinder head to ground the empty caps. This completes the circuit of the ignition electrical system and prevents any electrical problems from the caps being un grounded. Using the correct adapter for the threaded end of the tester,( same length of the spark plug threads length)screw in the tester in one plug hole. Hold the throttle wide open. Push the start button. Watch the compression gauge, when it peaks out at the most compression, let go the start button. Read the psi number. I would do it 3 times to be sure it is accurate. Check both cylinders the same way. The ideal compression is 150 psi per cylinder. If it is less, it's not a problem as long as they are close to being the same. If the psi is less than 90 it might need be time for a tear down and a rebuild. If the psi in 1 cylinder is say 140 psi and the other is 80 psi you need to tear down and repair. This difference is a lot then there is a problem. I hope this helps you.
Let us know how you make out.
Karl
__
To test compression, remove both spark plugs. Place spark plug caps on the plug cap studs near the cylinder head to ground the empty caps. This completes the circuit of the ignition electrical system and prevents any electrical problems from the caps being un grounded. Using the correct adapter for the threaded end of the tester,( same length of the spark plug threads length)screw in the tester in one plug hole. Hold the throttle wide open. Push the start button. Watch the compression gauge, when it peaks out at the most compression, let go the start button. Read the psi number. I would do it 3 times to be sure it is accurate. Check both cylinders the same way. The ideal compression is 150 psi per cylinder. If it is less, it's not a problem as long as they are close to being the same. If the psi is less than 90 it might need be time for a tear down and a rebuild. If the psi in 1 cylinder is say 140 psi and the other is 80 psi you need to tear down and repair. This difference is a lot then there is a problem. I hope this helps you.
Let us know how you make out.
Karl
__
It sounds like you should tear down the top end and rebuild it. With 90 psi the engine won't start too easy or have any performance. There might be corrosion internally or piston ring damage too, that's why you do a compression test.
Karl
Karl
then why would it idle fine after i cleaned the carbs out and now it wont could the rings have been siezed while it was running and wore the rings out. because it ran good on the trailer for about 30 seconds until i gassed and it pushed the truck a little bit then it wouldnt idle anymore and was hard to start.
- Status
