1989 115 Evinrude Reving up at idle

I am having an issue with my 1989 115 HP Evinrude. Before I have noticed sometimes it will run at a higher idle when its on the ear muffs out of the water but the last time I had it on the ear muffs it was idling very high about 2000 RPMs. Today I had it on the water and it seemed to idle high as well but when I got it home and put it on the ear muffs it was iddling high at about 3000 RPMs and then just kept going up and it 5000 RPMs so I shut it off. I haven't messed with the idle settings on the motor so I'm not sure what is causing this. I tried to rev it a little like you would a car to get it to idle down but this didn't help. Any input is much appreciated.

Re: 1989 115 Evinrude Reving up at idle

Your engine will idle much faster out of the water-there is no backpressue from the exhaust-it's not 24" under water. Usually up to 1500rpm's is normal when running on the hose. If the throttle linkage is not set correctly (a simple adjustment) it can run up to 2000. You must have something else going on to cause the engine to idle 3000 and above. Check the link arm connector between the spark advance lever and the timer base arm. If that link connector gets detached (the ball comes out of the socket) the timing can advance and cause engine rpm's to climb out of control. Also, check to make sure the throttle cable is functioning properly (it's not broken inside the casing).

Re: 1989 115 Evinrude Reving up at idle

The throttle cable seems to be functioning correctly. It runs normal while its in gear, only at idle do the RPMs climb on its own. A friend of mine called a marine mechanic friend of his and explained the situation. He said "without looking at it", it sounds like some kind of lower seal. (not sure which just know he said lower seal). He said out of the water with that seal bad it will suck air, in the water its under water so It cant suck air so it wont climb to high RPMs like it is outside the water. He said if this is what it is I'd be looking at $1000 and up because you have to pull the power head and split the motor to replace the seal. Does this sound accurate to anyone or have you had any experiences with this?

emdsapmgr said:

Your engine will idle much faster out of the water-there is no backpressue from the exhaust-it's not 24" under water. Usually up to 1500rpm's is normal when running on the hose. If the throttle linkage is not set correctly (a simple adjustment) it can run up to 2000. You must have something else going on to cause the engine to idle 3000 and above. Check the link arm connector between the spark advance lever and the timer base arm. If that link connector gets detached (the ball comes out of the socket) the timing can advance and cause engine rpm's to climb out of control. Also, check to make sure the throttle cable is functioning properly (it's not broken inside the casing).

Click to expand...

Re: 1989 115 Evinrude Reving up at idle

also, I removed the cover over the carbs and to make sure the flaps were not stuck open. They were not.

Re: 1989 115 Evinrude Reving up at idle

Bump, anyone have any input on this?