merc 20 runs bad

[farscapehw]

got my motor running and trailer back together and tested it out.

it cranks up and runs with choke on (choke closed). turn the choke off (open choke) and it shuts off. so i went back to the motor and used the manual choke and opened it just a little bit and it ran ok but had very weak power. once it warmed up it would not run with choke on or off but slightly open. i tryed adjusting the screw on the front of the carb but it did not seem to make a difference except when i tightened it all the way down. it wouldnt run at all.

any ideas? this motor is giving me too many problems...

serial# 4148481

 

[This_lil_fishy]

Re: merc 20 runs bad

Time to pull the carbs apart would be my guess. A good rebuild and float check...if you're mechanically inclined it's not a big job...if you're not take it to the mechanic.

Ian

 

[farscapehw]

Re: merc 20 runs bad

ok i took the carb apart and cleaned it, there was a bit of the bowls cork gasket stuck in one of the jets. now it runs great for about 20 seconds then it will not stay running in gear under a load.

i tried a couple of things, tapping on the side of the carb seems to make it get better but not for long.

took it back apart and bent the tab on the float a little higher so the needle seat seats better. still the same.

tilting the engine up out of the water makes the gas drain out the front of the carb... all of the gas from the bowl. then it runs great again for 20 seconds till the bowl gets full again.

it is flooding out really bad. suggestions please. ive taken this thing apart 3 times now.

 

[birdbrain]

Re: merc 20 runs bad

If it is flooding when the bowl fills, I suspect the float or float needle valve are not working properly. When this is the case, you may even see fuel come out of the carb. This may be redundant but your float may leak and take on fuel and will then not float. You may not have noticed that the float was full of fuel.

 

[25marshrunner]

Re: merc 20 runs bad

clean the seat where the needle valve goes then to check for sealing before reassembly put a hose on the fuel inlet on carb and blow into it it should take on air while blowing flip the carb in ur hand the valve should close keep flipping the carb upside down and right side up to check the operation.

 

[mark_gober]

Re: merc 20 runs bad

Does your prime bulb get stiff when you pump it? Mine wasn't and I was having very similar problems. Mine turned out to be a flooded carb float. It was never floating. I purchased a new one for $6 from a local shop and it worked great.

Mark