PROBLEM WITH 70HP YAMAHA TILLER

[Guest]

Hey people! I have a problem with the bottom cylinder on my outboard. When the motor is warm it acts as if a plug has fouled out but only on the bottom cylinder. The top two cylinders run great. When you check the plug on the bottom cylinder there is no evidence of carbon builup. It is just wet and oily. I am thinking it is an electrical problem. Any ideas of what you think the problem is? Any suggestions are greatly appreciated.

GOOD FISHN'---DLR

[TUMBLEWEED]

DLR, They say Yamaha are like Mercs. Well,my
Merc had one cylinder that wasn't working.Turned out to be the "spark-box" that splits the spark into three ways. I'm no boat motor expert,but the problem sounds similar??

[Guest]

Thanks, TUMBLEWEED! I think it may be either the ignition coil for the bottom cylinder or the Power Pack. I hope its the coil because of cost. Coil=$57.00 Power Pack=$281.00.

GOOD FISHIN'---DLR

[Guest]

TO DLR, A COUPLE YEARS AGO MY FRIEND HAD A FIFTY YAMAHA WITH ALMOST THE SAME PROBLEM, WE TOOK IT TO MARINE DEALER IN WALKER, IT WAS DIRT IN THERMOSTAT, IT RAN GOOD UNTIL IT GOT WARMEDUP AND STARTED RUNNING RUFF. IT ALSO WAS THE BOTTOM CYLINDER ON THE FIFTY. AFTER THEY FLUSHED OUT THE DIRT IT RAN FINE. SO I HOPE THIS MIGHT HELP YOU.
WALLEYE

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Bob's Guide Service
Remer-Grand Rapids, MN
Phone: (218) 566-2398

[Guest]

WALLEYE: Thanks, I will have that checked out also. I am taking it in for a compression check tonight in case a cylinder is scored and before I start replacing electronic parts.

GOOD FISHIN'---DLR