‘87 black max - max 2000rpms no speed

[Boateee]

Bought a 2nd hand ‘87 135hp black max with my boat. Ran it on water for the first time and couldn’t get it over 2000 rpms or ~10 knots. Would also show high temp at 2000 rpms.

I’ve seen some similar posts but never the resolution. Appreciate any help before handing to marine mechanic.

 

[Chris1956]

Perform a compression test and a spark test. Report back if she sparks on all cylinders and the compression of all cylinders.