PLEASE HELP mercury 402 40hp, wont start fuel problem - carb or reed valves??

[jamesbradley]

Hi,

I have a mercury 402 40hp 2 stroke ( think its probably mid - late 70's )

Basically it wont start, it has a good spark on both cylinders and good compression with no imbalance between the cylinders. fuel is getting to the carb, the resevoir on the carb is filling up and the float seems to be working and shutting the fuel supply off when its full. it seems like there is no fuel getting to the cylinders, it doesnt fire when I try to start it and the plugs are bone dry. I have cleaned the carb and it has had no affect.

I have heard people mention reed valves getting gummed up before but I dont know alot about them. Is there a way to test them? when they get gummed up do they get blocked and restrict the fuel intake or do they get stuck open.

could it be that I have the idle mixture screw set wrong on the carb?
( its the carb with the plastic manual choke flap )
Please help I am totally stuck with this engine.


Thanks,
James

 

[Laddies]

Re: PLEASE HELP mercury 402 40hp, wont start fuel problem - carb or reed valves??

Squirt some some fuel in the cyls. and see if it fires. If it does then you may have a broken reed, reeds don't gum up they do however break and the down side to that is the powerhead must be taken off and the crankcase split to repair them.

 

[mike0101]

Hi,

I have a mercury 402 40hp 2 stroke ( think its probably mid - late 70's )

Basically it wont start, it has a good spark on both cylinders and good compression with no imbalance between the cylinders. fuel is getting to the carb, the resevoir on the carb is filling up and the float seems to be working and shutting the fuel supply off when its full. it seems like there is no fuel getting to the cylinders, it doesnt fire when I try to start it and the plugs are bone dry. I have cleaned the carb and it has had no affect.

I have heard people mention reed valves getting gummed up before but I dont know alot about them. Is there a way to test them? when they get gummed up do they get blocked and restrict the fuel intake or do they get stuck open.

could it be that I have the idle mixture screw set wrong on the carb?
( its the carb with the plastic manual choke flap )
Please help I am totally stuck with this engine.


Thanks,
James

Hi James

Wondering how you made out with this motor. I'm having the exact same problem.

Thank Mike