Sea Ray 370 1992 7.4L rpm difference between engines

[ross_w]

I am buying a 1992 Sear Ray sundancer 370 with twin 7.4L mercruiser V drives. The survey shows the port engine only reaching 3900rpms and the starboard engine reaching 4500rpm's. Should I be concerned? The port engine was replaced and has 250 hours and the starboard has 600 hours. Thanks for any info.

 

[chiefalen]

"compression check, vacuum tes

"compression check, vacuum test? There alot of growth on the prop?"

 

[ross_w]

"Hull is dirty alot of algae,

"Hull is dirty alot of algae, fresh water boat, compression on both engine is good and even. Surveyor thinks possable linkage adjustment or secondaries may not be fully open? Not sure on props."

 

[chiefalen]

"It scares me how good i am.

"It scares me how good i am.

Pull the boat and clean the hull and drives, props also. Try it again and post the result."

 

[kghost]

600 rpms is a concern for dual

600 rpms is a concern for dual engines.

Prop pitch could be the reason. One pitch change could cause this.

You want both to reach max rpms within 100 rpms +/- a few.

If you can have a Mechanic run the boat and see if he can find the reason.

 

[makomark]

"Also, check to make sure both

"Also, check to make sure both engines are the same model. If the port engine was a generic replacement, the internals could be different and could cause this situation."