AQ145a RPM issue

"I have a houseboat with twin

"I have a houseboat with twin 145a's and 280 outdrives. On the port engine the RPM raises and lowers without input from the throttle except at idle. When I throttle up to anything above 1500rpm and leave the throttle alone, the rpm will run level then drop for a second and run back up. This weekend I was at 2300 RPM and it would run for a while then drop down quickly to around 1500rpm for a second or so and then back up to 2300rpm. I can here the engine changing RPM so I know it is not instrumentation. I have recently had a tune up and changed the fuel water seperator. Both engines are fed off of one tank and one fuel filter and the other engine does not experience this issue so I feel confident that it is not a fuel quality issue. could this be fuel starvation? This engine is the farthest one away from the fuel tank. Any ideas on how to troubleshoot?

Thanks,
Scott"

"Try to run the port engine wi

"Try to run the port engine with gas from a jerrycan and see if the problem persists, that will tell you if it is fuel starvation or not."

I will try that next time I am

I will try that next time I am at the boat. In the event that does not work... any other things that you think I should check...

And thanks for the quick responses... this is as good or better than IM!!!

"Considering it a possible fue

"Considering it a possible fuel problem, you may have a stuck anti-syphon valve in the fuel tank, or a stuck needle valve in the carburetor. But if we look at the problem as being a possible ignition fault, you may have a faulty connection in the ignition switch (or a bad ignition switch); a faulty neutral switch (if installed); a loose connection in the wire going to the coil; or defective points/condenser. If you find that it is not a fuel problem, try hotwiring the (+) of the coil with a jumper from the (+) of the battery. If the problem clears-up, you know where to search. The trick is isolating the fault to a reduced number of possibilities."