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Mercruiser 81 3200 rpm max

B

Bill Hoop

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"Have 2 8.1's inboards, On

"Have 2 8.1's inboards, One slowed down a few weeks ago to 2800 rpm's while the other would go up to 4200. Had Mercury come out as they are still under warranty and they ran a bunch of tests and said the injectors were dirty and sent them out to be cleaned. After cleaning I was told I would need new injectors. They re installed the cleaned ones and the engine ran up to 3300 rpm's. I found some new injectors out of a GM 8.1 engine and installed those however still at 3300 rpm. any thoughts out there?

Thanks,
Bill"
 
Call Mercury back and fuss wit

Call Mercury back and fuss with them. Sounds like a fuel pressure or electronic problem.
 
What did they say when they ra

What did they say when they ran the boat? It is obvious the injectors were not the problem.

The warranty procedure instructs you to:

A) Diagnose the problem
B) Repair the faulty condition
C) Verify that the problem is corrected

At least one of these steps was omitted. That also means that the two steps they did perform were not performed correctly.

I'd have them back out there today.
 
"This may be rather obvious, b

"This may be rather obvious, but I hope they changed the fuel filters on the engines. If crap got into the injectors that means that it got past the filters. Sounds like a fuel problem and possibly a restriction if you gain RPM after certain steps. Did they change the fuel filters?"
 
"Thank's for the responce,

"Thank's for the responce,
This problem has been going on for a month and I finally resolved last night.

Both the mercury mechanic and I messed up.
For future reference: I swapped the injectors from the 2 engines and MADE SURE OF A GOOD SEAL ON BOTH ENDS OF THE INJECTORS. This must have been the problem as both engines now run up to 4900 rpm's under load. You can actually hear a click when you pop the injector rail into place.

Hope this solves a future problem for someone and thank's again,

Bill"
 
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