Kind of at a loss with my mariner 9.9 need some hints

[Boathobo]

My 87 9.9 merc mariner isnt quite what she used to be. Used to be able to get the dinghy up on a plane no problem...popped out of the hole nicely. Now it seems to only have at best 75% of its power. Cant get up on a plane at all...almost but not quite.

I have taken apart and cleaned the carb and fuel pump. Seafoamed it half a dozen times. Compression tested both cylinders coming back with 85 and 90 psi respectively, not spectacular but not bad either. It will start and run under load on one cylinder, either cylinder. It starts with one pull and idles like a champ. Just no top end.

I love this old motor but I am at a bit of a loss as to where to look now and any help would be appreciated.

Thanks

 

[flyingscott]

Is the carb opening all the way?

 

[Boathobo]

Yep i think so....the vane is horizontal in the throat at full throttle. By that I mean flat.

 

[Boathobo]

Also replaced and gapped spark plugs

 

[flyingscott]

Did you replace any of the gaskets in the carb?

 

[roscoe]

air leak around carb ?

broken or bent reed ?

 

[DeepCMark58A]

Did you rebuild the fuel pump or just clean it up?

 

[Boathobo]

I just cleaned the pump and carb. Didnt replace any gaskets. No pinholes in the diaphragm that I could see. Gaskets all seemed in good shape too.

 

[Boathobo]

I didnt inspect the reed valve closely. I was under the impression that if they went they usually broke off and went into the crankcase.