Assuming this was a blue or white spark (3/8 gap) and it repeated this spark several times as engine was cranking
What we know;
Have spark
Fuel pressure is low but available at 30 psi
Remove flame arrestor, dribble a very small amount of gas down the throttle body. Crank motor and answer does...
Assuming carb motor
Start checking electrical connections, plug wires, the hard hit may have dislodged something. Does it still start and idle the same?
ok, your swapping the intake plenum not the intake
Still don't think it's fuel, more intake leak or temp sensor
Place voltmeter on intake sensor wire feeding ECM. Note voltage with key on motor off. Start motor and note changes if any
Your thread at Marine Engines list you swapped the ECM's and harnesses and there was no change. Swapped complete intake with all sensors and no change
Everything on the new motor works fine on the old motor, and everything on the old motor has no effect on the block motor. Prior to new long...
I'm not the best guy for how to weld a nut on stainless studs, I've only done steel. Machine shop should know how
So far as shimming, it needs to be measured and shimming determined even with using same
Don't fully understand the term but any kind of back fire or other in most cases is not the carb but timing and or the motor. Intake valve leak
Without more info I suggest a compression and leak down test
Not knowing how accurate the gauge used was, 41 is good enough for idle, should be closer 43 at 3/4 to WOT. Again it looks like fuel pressure is not the issue
Not putting the guy down, but there are some Marine folks that are great folks and may or may not be Dealer certified. Not that they...
