no top end power ?????

scott graham

Recruit
Joined
Aug 10, 2008
Messages
2
I have a early 90's 40 HP 2 stroke Evinrude that starts fine and idles fine. When given gas it only will run maybe at half speed. If choked it goes to full speed and then will flood itself if consistantly choked. It is not missing nor makeing any odd noises, just wont run at full power. A friend thinks it is fixable by messing with the air intake screws on the side of the carburator. I dont pretend to be an expert, but I thought it may be the carburator itself being gummed up. Although wouldn't that make it start hard and idle poorly? It does not set for more then one month at a time and I always treat the gas. any input is greatly appreciated.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: no top end power ?????

The high speed jets that are located in the bottom center portion of the float chambers are clogged. Clean the carburetors.
 

quackaddict1

Petty Officer 2nd Class
Joined
May 30, 2008
Messages
138
Re: no top end power ?????

Sounds like a blown gasket IMO, run it at idle in a tank, take carb spray and shoot it at the gaskets on the motor, if it is a gasket, you will spray and it will either die or pick up when you hit the sweet spot. Replace and you should be good to go.
 

scott graham

Recruit
Joined
Aug 10, 2008
Messages
2
Re: no top end power ?????

this is a dumb question, but the right forum to ask it in. I have never messed with a carburator. How hard will cleaning it be and should I even mess with trying to adjust the air screws on the caburator first? What would a ball park figure be if I was to take it to a marine shop? I sure hate to "fix it" myself and find out this winter on the river that I really did not fix a damn thing.
 

quackaddict1

Petty Officer 2nd Class
Joined
May 30, 2008
Messages
138
Re: no top end power ?????

A carb cleaning would normally go like 50-75 bucks, he will likley also help you trouble shoot any other problems.
 
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