Re: 1983 115hp problems?
Back in their day, these were considered some great engines. OMC's heyday-these engines were really popular. If you want to check for condition, the compression should be 95+ on all cyls, the gear oil should be full and the oil should appear clearish-no signs of water intrustion. You'll want to check spark on all 4 cyls when the engine is warmed up. If you pull a spark plug wire off a spark plug when running in neutral, the engine should slow in rpm's. Same for the other 3 spark plug wires. You should expect engine will idle in neutral without "sneezing" and that the engine will pull smoothly up to top rpm's (5500.) The power trim should work smoothly. Check or any exhaust leaks inside the cowling. The telltale should indicate strong flow. The cyl head temps can be measured with a laser temp gun-should be around 143-150 degrees at idle.
