Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

[theburlybiker]

I have a 1976 Boston Whaler 13 ft powered by a 1976 Evinrude 40hp. I've had this boat 3 yrs now. The 1st year it ran awesome, never had any problems. Then late last year was the first time i had it on a large lake where I could really open it up. It ran great all day long and then had a long ride back to the boat ramp, it started acting funny and loosing power. Later on I found that i had overheated it and blew the head gasket. (Pushed it too hard for too long). This summer I replaced the head gasket and it runs and sounds great, until i throttled it up into higher rpms when trying to cross the lake, whenever i would get up to a certain speed it would act like it slipped out of gear. When i would throttle back down it would take off again. This boat has no gauges so not sure what the rpms are at when this occurs. A friend of mine said he had a similar problem and found it was the shift lever (fork) in the gear case. So i opened up the gear case and can't see any signs of wear or loose play. I just bought a different boat and i'm wanting to get this fixed before i put it up for sale. I was at the boat dealer today to get parts for my other boat and was telling the parts guy about this problem and he couldn't give me any advice of what to check. He just told me not to worry about it, it's just a fishing boat and not meant to go fast. I'm planning on selling this boat this spring but i'd like to get this problem fixed first. I'd feel better about it, and I really dont' want to have reduce my asking price because of it. Any advice would be greatly appreciated. Thanks.

 

[Lyle29464]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

Sounds like the hub in the prop is slipping. Take prop off and look at the hub. Also you can mark the hub with someting and then run the boat and see if the mark is still in line.

 

[lindy46]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

X2 - sounds like a spun prop hub.

 

[theburlybiker]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

So if my marks are off then the hub is no good? I'm guessing it would be about as cheap to buy a new prop than to have this one fixed. Thank you guys for your advice. Wish I would of posted this thread before i split the gearcase.:facepalm:

 

[ondarvr]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

Having it fixed is normally less than half the cost of a new prop. Did you figure why it over heated? they normally don't over heat from being, "pushed hard", there is normally an issue that caused the overheating.

 

[theburlybiker]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

I assumed it overheated from running it too hard. I just replaced the water pump the year before and never had a problem with it pumping water. Unless maybe it had gotten clogged with something. I might install a new impellar while i have the lower unit off.

 

[steelespike]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

X3 on the prop hub.
Maybe the overheat was caused by a blocked intake or a thermostat malfunction.
Be sure the spark plug is the right heat range old number is L77J4.

 

[kbait]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

X4 spun hub. If you remember going through shallow swampy-mud before opening it up and overheating.. that's happened to me before, and all was well after cooling off-restart. I believe the mucky loon-crap just fell out when intake lost suction when the motor stopped.

New props here at iboats (best new price you'll find.. looks like $95): 40 HP Evinrude Outboard Boat Propellers 1960 - 1976 - iboats

You can likely find used from salvage for less than $50, and re-hub is probably $40ish. If your current prop isn't all banged up, re-hub is probably the way to go.

Good luck!

 

[theburlybiker]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

Thanks for all the advice. I think i'll probably order a new prop since theres no shops close by.

 

[Tim Frank]

Re: Acts like it coming out of gear at high rpms 1976 Evinrude 40hp

So if my marks are off then the hub is no good? I'm guessing it would be about as cheap to buy a new prop than to have this one fixed. Thank you guys for your advice. Wish I would of posted this thread before i split the gearcase.:facepalm:

That is why you should have an OEM repair manual.