Moter boggs/ dies, runs eratic @1/2 plus throttle

[Wildlifedesigner]

I have a 1980 40 HP 2 cylinder moter. Two days ago moter ran fine. went out yesterday filled gas tank with some 92 octain the same as befor. Now the moter basicaly boggs down at about half throttle, but runs and drives. At 3/4 throttle it will either die or rev up, then rev down, then rev up again and so on. At full throttle it revs up then dies. what may be going on? Thanks for any info Bryan

 

[marinegrh]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

try choking it quickly when its running, see if it picks up or drops, sounds like that good gas might have loosened up some bad trash and is blocking up the carb, just a thought, id try that first<br /><br />good luck<br />keep us infoed

 

[greasemonkeyozi]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

Try going to NAPA and buy some Sea Foam Deep Creep. Take your spark plugs out, spray a good bit in each cylinder, put back together, let sit overnight, and start it the next day. Then while motors running, spray a good bit in your carborators and watch all kinds of nasty stuff blow out your exaust.<br /> If this dont work, you'll need to rebuild your carborators, and your fuel pump... good luck

 

[Wildlifedesigner]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

Thanks for the reply marinegrh.When the moter was running a touch above idle and I turned the choke on it killed the moter pretty fast.

 

[Wildlifedesigner]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

And I will try out the sea foam by the end of the day

 

[Wildlifedesigner]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

Okay I used the sea foam got some new gas, new oil, two new sparks plugs, and a fuel filter got all excited but the boat still did the same thing. Anything else I can do?

 

[ZmOz]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

Sounds like you need more Seafoam!

 

[mellowyellow]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

look for air leaks in the fuel systems.....<br />sucking air instead of gas?

 

[dnewell]

Re: Moter boggs/ dies, runs eratic @1/2 plus throttle

Mercury.grease.rag.<br />I used deep creep in my carbs and know it sputters at take off anf runs ok wide open. What causes this? Thanks. Dale