Engine Shifting/High Speed Troubles

[Ruler]

I've been having a couple of different problems with my 25 horse 1988 Evinrude. I do not know if they are related.

Every now and again, the engine won't shift out of gear into neutral. I've found that when this happens, I pop the shroud off and look for a gold colored piece of metal on the left side of the motor. It is rotated such that it blocks the pin from coming up; I turn it out of the way so that the blank spot in the metal is above the pin and it shifts perfectly.

A more serious problem is something that happened when I was coming in Saturday night. The engine will run fine, but when I rev it up, the boat stops and the engine keeps going. It happens about 7-8 mph on my GPS. I'm guessing that something inside the transmission is slipping, but have never had one apart. I tried putting it in gear and manually turning the prop, thinking that maybe the clutch (as it has no shear pin according to brennan marine) is worn and slipping, but was unable to turn the propeller with the engine in gear. I may not be getting enough force on it though, as it only happens at higher speeds.

Any advice is appreciated.

[Ruler]

By the way, the engine was fine when I went out late Saturday afternoon - went too well actually, as I got soaked from hitting the rollers. I didn't hit anything during the trip, but didn't too too awful bad on the fish - check out the warm water forum for a report soon.

[double trouble]

check your prop. the hub could be going bad.cheap solution for an expensive idea.i once boughe a 1978 115 evinrude with power tilt that the owner said had a blown piston. he said it would only run 5 mph.turns out 1 bad prop.paid 50 bucks for it.tried to use that prop on another 115 i owned and would only go 5 mph. imagine that.

[FREEPOP]

:yeahthat:

prop slipping

[rustyfisher]

I have had the same problem with my 14 ft duck boat (25 evinrude motor). I just redid the transom a few weeks ago and raised it 3 inches - even with the stern. The cavitation plate is within a half inch above the bottom of the boat. I didn't have this rev problem last year but on my last duck trip I nailed a few logs as well. I could lower the transom again- but are there any ways for testing to see if it is the prop without buying a new one?
-rustyfisher

[MSUICEMAN]

i don't know if your motor has a sacrificial hub or a shear pin, but it might be that problem. Maybe spun a hub, maybe shear pin is broke and somehow has enough friction to run at low speeds, then when you ramp it up it slips.

As for the shifting thing, it seems like a linkage is out of whack, but i'm not the best at these type of things, so I'm gonna leave it to the experts.

steve

[Hotwired]

To test for a slipping hub you can score a line on the prop and the hub and see if they are misaligned after the next use.

[double trouble]

hey wired . good idea. must be from experience? Dan

[FREEPOP]

rustfisher, you could've raised your motor too high and as a result get cavitation. This is not good for a motor. You can melt a prop and it over-revs the motor, which will reduce it's life. You can get power trim, to adjust to prevent hitting logs and then put it down for running on plane. The other alternatives that come to mind are, a power jack plate or manually adjusting the motor.

Good luck

[Ruler]

I took the prop apart tonight - a lot simpler than I thought it would be. Took the cotter pin out and unscrewed the nut, then a rubber gear-like washer. This had some scoring on the back of it and little flecks of rubber fell out from between the two surfaces when I took it off. I cleaned it up, then put it back on. I'm going to give it a shot tomorrow somewhere. I'm thinking that if it doesn't work, put it on backwards (front and back are the same except for the wear) and/or use a very thin washer between the nut and the rubber gear-like washer to tighten it up. It'll at least keep me using the boat until I can get a new part.

I'm going on the assumption that this is what the problem is; I drained and re-filled my lower unit oil and there were no shavings in it, so I hope this means it's not there. :)

[Ruler]

Went out on Saturday and had it revved up - works like a charm now. I guess that powered rubber must've caused the prop to slip for some reason. Weird, but I'm not gonna argue with it! :)

Thanks for the advice guys.

[double trouble]

just remember that part will fail soon. i would replace that and get a spare prop too. even a used one. insurance against getting towed in. Dan :)

[FREEPOP]

Ruler, that rubber washer is the weak link between your prop and the shaft. I case of a big hit, it'll spin there. Maybe it was too loose or something but if it looks as though you lost much rubber, I'd get a spare. I have learned that when on the lake, it's always good to have spare parts.

Good luck

[wildcoy73]

yes sound like a spun prop hub take the prop off and look at the back side if you see rubber pieces hanging out or smell burnt ruber the hub is spun

[Ruler]

Well, I figured out the second (serious) problem. I was out off standish in the bay on wednesday and the *exact* same thing happened. I cut the engine and pulled it up and saw a glob of weeds about the size of a basketball float away behind the boat. There were also some wrapped around the prop, so I'm guessing that they were causing the prop to spin too hard and whatever is meant to give did so. Since it was pitch black by the time I got in at Quanicasee when this happened before, there was no way for me to see a glob of weeds as it floated away from the dock before I pulled the boat out of the water.

[FREEPOP]

Weeds will definately cause a problem, as they won't allow your prop to get a bite in the water.