20HP Mercury 1990

jonny canuck

Cadet
Joined
Jul 23, 2010
Messages
10
1) Took the carb off and put in a new kit. Carb was clean and so were the gaskets. Fuel pump was too. New parts all around.

2) Changed the two ignition coils. So now new coils and leads.

3) My rectifier was rusty and ugly. So another part added.

4) New fuel filter and gas tank

WOW! Guess I've turned into a parts changer.

So this is the run down of how its performing. Starts fine on the first pull every time. Idles, no problem. Start to throttle...no problem. 1/2 throttle...no problem. About 3/4 or so it starts to shake and sounds crappy ( missing ). At WOT motor bogs right down and shakes bad and sounds really bad. Turn throttle down everythings normal. Any suggestions would be greatly appreciated.
 

sxmerc

Petty Officer 1st Class
Joined
Jul 13, 2010
Messages
247
Re: 20HP Mercury 1990

Did you install the gasket between the carb and the intake correctly? There is a small pulse hole thee that drives the fuel pump. If you installed the gasket so that the hole is covered, or got some sealant in the hole, you're fuel pump is not going to perform correctly. This is a easy check.
 
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