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97 120hp mercury force, missing/ #3 plug wet 1,2,4 dirty?

T

texcar4u

New member
I just recently had the reeds changed out due to sneezing from 1 carburator, but now i notice when i go to throttle up a miss. I ve checked my plugs and the #3 plug is wet, all others are dirty. Checked spark and i have spark from all coils. Swapped plugs, same thing. Checked compression, 115 all four cyls. Anyone have any ideas?
 
Possible head gasket.Even though it's got good comp it might be leaking enough to be wet and still maintain pressure.
Happened to me once.
Had 145# all 3cyl yet it missed.would run OK for a bit,then start missing.
Pull the head and inspect the gasket.
#3 from top operates the fuel pump.Check the diaphram too.
Compression should be about 150# maybe the guage is reading wrong.Different guages,different readings.
You remove all the plugs.Install the guage.Then let it turn over 8-10 times?J
 
thanks for the reply. The mechanic recommended replacing fuel pump, filter and lines when he changed reeds. I'm going to do those myself. He wanted me to bring the boat back in to check the missingbut that was going to run me another $100 so I thought I'd do research first. Thanks again!!
 
Jerry is right about the compression. I was reading 120 on all cyl and thought there was no way water could be coming in from there but sure enough it was. Check the head gasket.
 
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