Suzuki 55hp loss of power

mumma11

Cadet
Joined
Aug 4, 2011
Messages
8
I have a 1989 PU55 jet 3cyl. that lost power today. Planing fine then fell on its face, would go at low rpms, but not rev up much. Motor was "sneezing" also. Limped back to dock stopped several times, then motor wouldn't start. Pulled plugs. Top had black looking oil coming from around the base, middle was ok, though oily like the top, and bottom was black with carbon. any help would be great, and thanks again.
 

mphelle8vld

Petty Officer 1st Class
Joined
Aug 17, 2005
Messages
320
Re: Suzuki 55hp loss of power

Nothing wrong with a compression check but my first guess would be the fuel pump. If the diaphram tears or gets a hole worn in it, fuel will be sucked into the bottom cylinder through the small passage that provides vacuum to operate the pump, which would account for the bottom spark plug being sooted up. Loosen the two mounting bolts and pull the pump free of the powerhead, squeeze the primer bulb a few times until you feel a little pressure and then look for fuel leaking from the fuel pump diaphram through that small hole in the back of the pump. If there is fuel leaking, rebuild the pump.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
7,596
Re: Suzuki 55hp loss of power

compression and spark are easy to test and if they are good then it is on to look at the fuel
 

mumma11

Cadet
Joined
Aug 4, 2011
Messages
8
Re: Suzuki 55hp loss of power

I checked the fuel pump as suggested, nothing leaking from back of the pump. I squeezed the bulb about as hard as I could. I was thinking spark problem, since the plugs looked wet but I don't know how to check each one. Looks like its off to the shop. Thank you all.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
7,596
Re: Suzuki 55hp loss of power

a spark tester or an inductive timing light hooked to the individual plug wires will show if it is getting spark.
Testing the inputs and out puts of CDI is a better test if you have the proper equipment.
Here is some good reading on testing CDI systems
http://issuu.com/cdielectronics/docs/troubleshootingguide

If it was lean sneezing I would think it is a fuel problem,
but it is always best to eliminate the simple things to test 1st
 
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