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1991 90 Hp running rich

vane

Regular Contributor
I have a 1991 mercury 90 HP 2 stroke 3 cylinder,That is running very rich.Starts up pretty easy.I rebuilt the carbs a fuel pump 3 months ago.Did a compression test last week all 3 cylinder were 115-118.So compressions fine,And adjusted alll floats in carburator yesterday.But when the motor is running Its smells real rich,hit the choke{enrichen sileniod} to to see if it was stuck and motor stalled ,so I don't think thats the problem.But there a little hose that runs from behind oil tank that goes into a nipple between the lower part of the power head and exhaust leg.Seems like crank pressure goes into the hose,with the motor running, I remove that hose it smokes and mist of fuel.with motor off I remove the hose and fuel drips out for a couple seconds then stops.Is that OK or is there something wrong there.could it be something with the fuel pump again,being the fuel pump runs off of crank pressure.
 
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Re: 90 Hp running rich

I have a 1991 mercury 90 HP 2 stroke 3 cylinder,That is running very rich.Starts up pretty easy.I rebuilt the carbs a fuel pump 3 months ago.Did a compression test last week all 3 cylinder were 115-118.So compressions fine,And adjusted alll floats in carburator yesterday.But when the motor is running Its smells real rich,hit the choke{enrichen sileniod} to to see if it was stuck and motor stalled ,so I don't think thats the problem.But there a little hose that runs from behind oil tank that goes into a nipple between the lower part of the power head and exhaust leg.Seems like crank pressure goes into the hose,with the motor running, I remove that hose it smokes and mist of fuel.with motor off I remove the hose and fuel drips out for a couple seconds then stops.Is that OK or is there something wrong there.could it be something with the fuel pump again,being the fuel pump runs off of crank pressure.
Just took the fuel pump apart to see if maybe there was a hole in diaphram,no lucky the diaphram is fine.the plastic disks Think there called check valves in it look to be fine also.
 
Re: 90 Hp running rich

See if the enrichener is shutting off tightly.

Jeff
Ok will do in the morning little to dark now.to do that ,I just have to pull bottom hose off enrichener and see if fuel come out while its running,correct,Thanks for the Help.fastJeff.
 
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Re: 90 Hp running rich

See if the enrichener is shutting off tightly.

Jeff
Removed to line from the enrichener and it is not leaking,only when I hit the choke button is it squrting out.when I release it it stop totally.I shut the motor off and pulled the little hose thats runs behind the oil tank from the top of crank case to the bottom and let fuel leak out.put it back on and started it,it seem to not smell rich like it has been,and motor ran better for about 2 minutes. then it started smelling rich again and running rougher.is there suppose to be any fuel in the crank case.
 
Re: 90 Hp running rich

I check the enrichener again and it is leaking fuel out of it without pushing key in.so going to pick a new one up tomorrow.Thanks fastjeff you called it right again.Much appreciated.Thank you for your time..
 
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