Last year I purchased an 87 Gibson with a Chevy V-8, Volvo Penta
outdrive with dual props. Engine starts, idles and revs
just fine in neutral, and accelerates fine in gear up to about
2000rpm. Above that the whole drive train begins to vibrate a
bit and it will not accelerate above about 2600 rpm. I can
take it out of gear and engine accelerates fine again, smooth as
silk. Is there some kind of limitation inherent in this set
up? My wife says "it ain't a sports car" but I can't believe
there isn't something wrong here. Didn't notice this problem
on purchase (shame on me) and prior owner told me later he thought
he had a plug fouling problem. Thanks for the help.
You may have a weak ignition coil, or possibly need timing adjustment. Do you have electronic ignition or points? if you have points, now is good time to convert to the electronic ignition and eliminate that problem once and for all.
Engine timing has been checked and plugs replaced. Engine has
points--had to replace a cracked distributor cap last year.
Electronic ignition a good idea, but engine runs just fine
now--smooth acceleration up to 4000+ rpm when in neutral.
Only when loaded does it bog down above 2200rpm.
Here's what I would do. First check to see if the prop is fouled with weeds and stuff. If it is clean, check to see if it looks 'normal' in terms of size and pitch. that part may not be easy to do. I doubt if there is any gear problems in our outdrive, so you can then move on to engine problems.
Sometimes an engine will sound OK even if the spark wires are switched. Check a tech manual. Next in order of checking might be the distributor--under the plate that holds the points/ igniter unit. With cap off, twist the rotor button both ways. It should not want to move one way----but the other direction it should move about 1/2 incch and then spring back when you let go. If it won't do that then you probably have stuck weights or broken springs under that plate.
Last thing I would check is the carburetor, if your engine has one. Maybe the secondary throttle linkage is stuck. That is time to call your mechanic. Cheers!!
lookin' for adventure and the next wild engine!
Engine tamer (damn! wish you guys weren't so afriad to give at least a first name) is leading you down the correct path. One other thing is fuel filter/water separator. Should be changed yearly. Remove and pour contents (away from sparks ane open flame) into a clear or white bowl/container and see what's in there.
I carry a gun because it's too tiring carrying a cop.