Originally Posted by bolger
when ideling up to 2000 rpm but inbetween 2000 & 6000 it runs slugish & jumps from 6000 to 2.5.Sometimes it will all of a sudden run right up to the max. of 7000 rpm & stays there, running perfectly until I take it back down again,all with the idle throttle of course.
DON'T run in neutral at that speed or you'll be adding to your problems......
Sounds electrical if it jumps. I had a similar thing on mine at load that got progressivley worse, then found one of the spark plugs was well on its way to being short circuit. (Megger proved that). Mine's 2 cyl and so it was quite obvious what was happening as one was cutting in & out like it was on a random switch. Pulsing high voltage does some funny things with semi short circuits, and spark plugs don't last forever......
I'd check & clean all the electrical connections in the engine first - it's amazing what 20 years of salt air can do to a bullet connector. If that doesn't cure it then change the plugs, it should be a cheap test. If that doesn't work, I'll echo NoS' comment & say go to a dealer.
Incidentally, does it do the same afloat and under load? (i.e. in gear)