took my new to me boat out last weekend and it will slowly accelerate to 20mph with the throttle at full throttle. It has new spark plugs, fuel filter, and battery. anyone have any suggestions as to where i should start looking for problems?
While in the water--
Check spark on all 6. What is your max RPM at WOT?
On the trailer--
Are your plugs the recommended NGK type?
Compression test with all plugs out, WOT. Hoping for 130psi. As you take the plugs out; check each one. Are they the same? Some wet; some dry?
Fuel pressure-- Should be 36psi with key at RUN. When you turn key OFF, how long does it take for pressure to drop? Should be several second to minutes.
TPS--can cause problems at part throttle, but less at WOT.
Trigger-- 6 wires come out from under flywheel, starboard side. Open the connector. Check the resistance of each pair. I don't remember the spec, but they should be close to the same.
Check all your ground wires. There are several. No green connections allowed.
