I seem to have a weird top end surging problem that is different from what I have found in searches.
The boat pulls fine from a start, planes out, then builds a few rpm and then it will surge in power. It is a constant surge, like a Vtec or something.
The surge seems to be very RPM specific (don't know which rpm because the tach broken), after I plane out, I will keep WOT throttle, hear the rpm's build, then it will boost in power. Then I can back out of the throttle, rpm's will start to fall, and it will find that rpm again and loose power. So it seems to me to be independent of throttle position.
I have changed fuel filter (inline and carb).
Fully cleaned the carb.
Checked choke and throttle plate operation, and all seems to be normal.
Changed plugs. (old plugs looked fine)
The power increase is quite significant and sudden. It seems to be too sudden to be a fuel thing, I would think if it was going lean, the surge would be slower.
I am less familiar with engine ignition systems (especially on boats), is there something non-mechanical that adjust the timing based on rpm?
Also, WOT power is great, drives smooth. But after I drove it hard for a while I had starting issues (probably a different issue).
The boat pulls fine from a start, planes out, then builds a few rpm and then it will surge in power. It is a constant surge, like a Vtec or something.
The surge seems to be very RPM specific (don't know which rpm because the tach broken), after I plane out, I will keep WOT throttle, hear the rpm's build, then it will boost in power. Then I can back out of the throttle, rpm's will start to fall, and it will find that rpm again and loose power. So it seems to me to be independent of throttle position.
I have changed fuel filter (inline and carb).
Fully cleaned the carb.
Checked choke and throttle plate operation, and all seems to be normal.
Changed plugs. (old plugs looked fine)
The power increase is quite significant and sudden. It seems to be too sudden to be a fuel thing, I would think if it was going lean, the surge would be slower.
I am less familiar with engine ignition systems (especially on boats), is there something non-mechanical that adjust the timing based on rpm?
Also, WOT power is great, drives smooth. But after I drove it hard for a while I had starting issues (probably a different issue).