200hp rpm's going up and down over 3500

[flabullherder]

I've got a 1987 Ocean Runner 200 with a '94 225 powerhead. The powerpack and plugs are new, as well as the fuel filter and water seperator. The oil injection system was removed by the previous owner and I mix the oil 50:1. It cranks fine and opens up fine, but after a few second opened up, the rpm's start swinging. If I'm over 3500 rpm, the motor goes up and down from 3500 to 4500 and back down again, back and forth. If I back of below 3500, it smooths out. Any ideas? Thanks for the help.

 

[codkiller]

Re: 200hp rpm's going up and down over 3500

flabullherder, I had a similar problem on a 1990 200 Evinrude. Turned out to be the inner magnets on the flywheel had come lose, OMC replaced the flywheel under warranty, problem solved.

 

[flabullherder]

Re: 200hp rpm's going up and down over 3500

Thanks for the info. I'll pull out the manual and take a look.