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9.9 Merc

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Paul McMillan

New member
Hello
I purchased an 1989 9.9 Mercury (serial 0B392786) that had been stored for up to 10 years and used very little up to that time (and appears so)

I placed it on a 10 foot Squirt and it just does not seem to be running at full speed when wide open. I did remove the tiller controls and connect remote control as I did with the 6hp it replaced. I verified the throttle opens fully via the remote

I dismanteld and cleaned carb twice, replaced water pump and gear lube, new plugs and it runs great at idle and even higher but compares very closely to the 6hp it replaced.

Any ideas in where to look next? Compression has not been checked but went pulling over it compares to other Mercurys

Thank you
 
Thank you

I will get the parts this weekend and check the pitch of the prop

I thought the prop pitch would be standard for a 9.9 so what pitch am I looking for to run a small boat?
 
If the prop is (factory original) it will be a 9 pitch which is (standard) for a boat upto about 14 feet or so.

I would also grab a can of Merc's "PowerTune" (about 5 bucks a can) and just follow the directions - it will clean out all the carbon and other "cooties" that motor has collected from sitting so long...
 
Thank you, I will pick a can up when I drop by the dealer

I won't be back up to re-install the carb until next weekend but I will let you know how I make out
 
Well I thought I would update on this situation. After rebuilding carb and installing a switch box I still had problems with fuel to the point the motor just would not run. The bulb on the fuel line would not get hard, so I bought a new primer bulb and still the same issue. So I looked at the last possible item and removed the screws holding on the tank pick up connection and float assembly to discover the pick up fuel line had dissolved! Just the clamp and a tiny bit of hose. I replaced and we're running beautiful. I can only imagine when my problems began the hose was still intact but in very bad shape allowing air into the system. Oh well, at least I have a switch box on hand
 
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