Good Compression Numbers & Leak Test Numbers for 01 150 HPDI

[johnbass1]

Hi all! I'm planning on getting my first "real" rig and was wondering what the
compression should be on all cyclinders. Also the leak test, what should that be at?
Any info would greatly be appreciated!

[esoxfly]

That's a toughie. There's alot of opinions on this, and it can even vary based on how the technician takes the reading and what kind of gauge he uses!

I like to see above 100 psi on a used motor, and all have to be within 10% of each other. I used to think that 120 was more what I wanted, but I've had more than one outboard mechanic tell me that 100 is plenty on a used motor.

[yamahatech]

The compression should be 100-120 psi and should be within 10 percent of eachother. The leakdown should be no more then 20 percent.

[johnbass1]

Thanks for the info. guys! Much appreciated!