I’m stumped!!
I have two primary issues that I believe are related
1) RPMs surge +-200 from 2500-3500. This is so bad it causes the boat to porpoise significantly. Above 3500 it runs out fine with plenty of power.
2) A vacuum leak that sounds almost like a ticking that increases/decreases based on rpms. Also when you turn off the engine with the hood off, for a second or so a steady hiss occurs. This sounds low and toward the front half of the engine.
I ran propane around the intake and upper seal with no change in rpms but I did not get access to lower seal. Cleaned carbs, timed, new plugs (old ones were consistent and looked good) ran a heavy dose of sea foam and pulled reeds which appeared fine.
Any ideas/suggestions are appreciated
I have two primary issues that I believe are related
1) RPMs surge +-200 from 2500-3500. This is so bad it causes the boat to porpoise significantly. Above 3500 it runs out fine with plenty of power.
2) A vacuum leak that sounds almost like a ticking that increases/decreases based on rpms. Also when you turn off the engine with the hood off, for a second or so a steady hiss occurs. This sounds low and toward the front half of the engine.
I ran propane around the intake and upper seal with no change in rpms but I did not get access to lower seal. Cleaned carbs, timed, new plugs (old ones were consistent and looked good) ran a heavy dose of sea foam and pulled reeds which appeared fine.
Any ideas/suggestions are appreciated