Mercury 50 HP not starting

[electra]

It is a 1985 50 HP Mercury that will not start : It ran well all summer but recently started flooding when I started it ( fuel was pouring out of top carb)- I changed the carb. inlet needles and this stopped fuel pouring out of carb.

Since then it has refused to start . Put new spark plugs in and there are good sparks. Carbs are clean. Fuel is recent and good ratio ( 50 :1 ). Good compression ( Top : 115; #2 :115; #3 : 110 and #4 could not reach it...)
Battery is fully charged .

I am at a loss for where to go from here and any help would be gretly appreciated !

Thank you !:

 

[tonxs]

Re: Mercury 50 HP not starting

hi try this put a little petrol down two of the boares.next take two of your plugs .and warm them up till hot with a blow lamp. put plugs back in were you put the petrol in engine. then give it a go should start.98 of the time doing this will kick engine in to running .

 

[electra]

Re: Mercury 50 HP not starting

Tonx,Thank you for your help - I tried what you told me ( first with no choke then with choke, then with open throttle )but still nothing ! I cannot beleive it.....

I took the spark plugs out ; The 2 ( heated ones ) were dry and the 2 " cold " ones were moist.

What to do next !

Thank you for trying to solve my problem ! I do appreciate it.

 

[tonxs]

Re: Mercury 50 HP not starting

right do the same again. get your self a tin of esay start .and when your turning over the engine ... spray some in to the carbs not a lot .it sud at least fire. if still no luck. have you got a sort.when plugs or back in.??? or thay fireing???. all so it may be your kill switch???. also is the mercury switch ok. this can stop your engine fireing. its to stop you starting your engine.when its up.give it a go. regards tony

 

[electra]

Re: Mercury 50 HP not starting

Thank you, Tony !

I will try this tomorrow with easy start and hot plugs - I have checked the mercury switch and it is fine. I have also checked all my wiring etc. One thing I would like to know is how to check that the spark plugs are actually sparking when they are in the cylinder.

Quentin Victoria ( British Columbia )

 

[outhere99]

Re: Mercury 50 HP not starting

Did you replace the floats in the carbs? I did on my '86 and it's run great ever since. Maybe your floats just need an adjustment.

 

[tonxs]

Re: Mercury 50 HP not starting

to test spark plugs. .....take one sparkplug cap off put a plug in cap.... earth to engine. if it sparks the rest will be ok. have a look at the timeing marks as well. good luck tony