Confused and need help

[The Moose]

We installed a rebuilt powerhead and a new ecm. With the original powerhead and the stock 17P prop we could get 5400 rpm. Same prop we can only get 5100. Just for @#$! & giggles tried a 19 P enertia prop and could get 5100 rpm, next tried a 17 P mirage plus and can get 5100 rpm. According to conventional wisdom the 17 P prop should gain 400 more rpm. Could the ECM have a rev limiter or is there something wrong? :?:

 

[jcmcclellan]

New powerhead broke in yet? That could make a couple hundred rpm difference.

 

[The Moose]

Powerhead well broken in. Don't get me wrong the engine runs great !. Just can't get the rpm I'm supposed to

 

[captbone]

The enertia is designed to give you extra rpms because of the X7 alloy. You should have picked up speed with the 19pitch Enertia. A 19pitch Mirage plus would have dropped you rpm the correct 300-400 over the 17 pitch Mirage.

Your tach could be off also. What type of engine?

 

[The Moose]

1997 ox66 250 hp on a 2320. Testing props to increase economy. Does the ox66 have a rev limiter?

 

[The Moose]

any suggestions on waht to look for

 

[The Moose]

any suggestions on waht to look for

 

[The Moose]

After doing some more research I've decided to recheck the throttle linkage, TPS, and the O2 sensor. Will doing the research I notice there is some confusing about the oil rod adjudtment. The Seloc manual I have says .040 gap between the stop and lever, other sources say no gap. If there is anyone still running an OX66, can you tell me what gap you are using?g

 

[The Moose]

Thanks for the reply, I'll give Andy a call

 

[Megabyte]

Might I suggest yer call Andy at Shipyard Island Marine ? He's the resident Yamaha expert and our discount Yamaha parts supplier.

Good advice.
Tell him that ClassicParker sent you. :wink: