35hp Mercury. Carb flooding.

[phumba]

Hi. Am new to boating and not to familiar around motors. My 35hp Mercury (25hrs) which started/ran faultlessly suddenly developed the following problem after standing for 3 weeks. (I did not run the carb dry so 2stroke oil in carb could be a factor.) Took several pulls before starting and then ran unevenly before cutting out. Subsequent attempts to start it caused it to flood. After disconnecting fuel line and cleaning the plugs the motor started on the 7-8th pull and ran faultlessly until I reconnected the main fuel line. Motor dies almost instantly with petrol pouring out from under the (overflow?) plate on top of carb. Repeated the process several times (Takes a good couple of pulls to start). Does not want to start whilst fuel line is connected and fuel overflows whilst priming as well. Of concern was also noticing a oil leak under the prop after all the starting attempts. The motor never leaked oil before. Could this be excess 2stroke (was black and sticky) or did the propshaft seal get damaged.

HOpe it is not to serious.

 

[bgbass.1]

Re: 35hp Mercury. Carb flooding.

sounds like you need to rebuild carb. its not hard but a manual is mandatory. as far as the black gunk its unburned fuel.

 

[phumba]

Re: 35hp Mercury. Carb flooding.

Thanks. I'd better take it in to the proffesionals. What would cause a failure like that. It was serviced approximately 3hours ago and was running well, then parked for 3 weeks and all of a sudden would'nt start. Could it be because I did not run the carbs dry before parking it or could a bump while being towed have caused it. Would like to no how to avoid this in future.

 

[JOHN12]

Re: 35hp Mercury. Carb flooding.

Stuck float??

 

[Fenwick2]

Re: 35hp Mercury. Carb flooding.

Stuck float; sea foam is a option and there is another way to fix it; gently tap on float bowl. More detailed way someone else can explain as I'm only a rookey. Stuck Choke?? Pull cover to check Choke position.

 

[stev-o]

Re: 35hp Mercury. Carb flooding.

im a rookie myself i got a 86 cobia with a 135 blackmax and it runs great but it doesnt like to idle and its hard to start, smells like its flooding at idle ,any advice on whats happening,thanks

 

[buddhapi]

Re: 35hp Mercury. Carb flooding.

we ran into the same thing today with a 6 hp Mercury. the guy we had rebuild the carb had the 2 metal "flapper" pieces under the needle mixed around, and the float was coming up about 3/16" too high, which gave us major flooding out of the seep hole in the float bowl cover. now, she runs like new.

 

[norman20]

Re: 35hp Mercury. Carb flooding.

Had a similar problem with my mercury 20 over this weekend gone, got stranded about 8 miles from home on the river thames,

engine cut out middle of the river, near marlow used my seagull aux engine to get to the side,

after turning over and squeezing the primer bulb fuel was streaming out the top plate of the carb, the bulb literally disentegrated in my hand,slept on the boat the wife picked us up sunday morning went and got a replacement bulb, back to the boat fitted it boat started ran ok put her in reverse came out ok went forward cut out after 20 metres,

Had to get her back to my local slip using the seagull engine, ran fantastic and got me back to where i needed to be (slowly),got the boat out and home on the trailer.

Had a good look today, sprayed the carb with cleaner still no joy ,then noticed the fuel pipe to the top of the pump was seaping a bit of fuel, this had been masked a bit by the sheer amount of fuel coming out the top of the carb put a new clip on started the engine, all seems ok now (fingers crossed)