Mariner 60HP craps out suddenly

[Gar Hunter]

1988 Mariner 3 cyl 60HP has run fine for years when this prob suddely happened . Was running full tilt when engine suddenly slowed down and stopped...I thought fuel starvation, so when I got home I changed the primer bulb on the tank, checked the fuel/water separator and connection to the engine. Tried to run it today...it starts up but I must increase the rpm at idle to kkep it from dying.Whne I put it in forward and try to get out of the hole...it increases only to a very slow speed maybe 10 mph and wont go any faster...<br /><br />Im about to change the fuel pump diaphragm, if I can find a kit nearby for this engine...the plugs seem Ok and not fouled but I suspect its something more involved but have no clue...<br /><br />Ive orderd shop manuals from the library, but Ive yet to see one which has a troubleshooting tree instead of merely chapters on various systems...<br /><br />other than these procedures, I have no clue..

 

[andrewkafp]

Re: Mariner 60HP craps out suddenly

And you probably won't...<br />Best trouble shooting I've found is right here in JB world...

 

[roscoe]

Re: Mariner 60HP craps out suddenly

Could be fuel starvation, can you pump the bulb up and does it stay firm or go flat?<br /><br />But sounds more like you have dropped one cylinder.<br />Check spark to all plugs. <br />Check compression on all cylinders.

 

[Gar Hunter]

Re: Mariner 60HP craps out suddenly

fuel starvation? the bulb remains pumped and as its new it seems harder than the one I took out.<br /><br />Dropped cylinder? does that mean a piston or rod is bad....ie major engine work....<br /><br />How do I check plug firing and if one isnt wouldnt that be a powerhead problem.....?<br /><br />compression check? remove plug screw in tester and quick turn starter key....