'84 Evinrude 115hp V4 VRO high RPMs, loss of thrust at above 2/3 throttle

jayrdubya

Recruit
Joined
Jun 1, 2009
Messages
2
I have a 1984 Evinrude 115hp V4 VRO. I took it out over Memorial weekend and ran into a few problems. First of all, when I took it out, I tried to get it up to full throttle, but couldn't ever get there. Anything above about 2/3 throttle and as the boat started trying to plane, the RPM's shot WAY up but the boat's speed did not increase...I actually slowed down. My assumption is that I've spun the bearing, though I'm not entirely sure what that means or where to begin fixing it. Later, I noticed a large fuel leak coming from the bottom of the silencer. When I primed the bulb, almost immediately, fuel began to leak, not drip, but run out from the bottom of the silencer. I tried to pull it off, but I couldn't get the bottom bolts off due to a lack of tools at the lake. I primed the bulb again and looked down into the silencer cover and saw it was draining from the bottom barrel. Am I looking at a carb rebuild or replacement, or is it something easy like a stuck float that really needs cleaned up? Any advice you all could give me would be great. I am an average mechanic but am not afraid to get into something to fix it. I am however, not that great at troubleshooting. Thanks.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: '84 Evinrude 115hp V4 VRO high RPMs, loss of thrust at above 2/3 throttle

It is more likely that you have a spun prop, which means that the bushing between the inner and outer sections of the propeller hub has released due to age, heat, or from stiking an underwater object.

You can test it by scribing a mark across the face of the prop, using your cotter pin as a pointer. If the pointer moves out of line, you will need to have a prop shop repair the bushing or replace the propeller.

The repair/rebuild of your carburetors is fairly easy, but getting them on and off can take a little time and patience. Spread a cloth under them while you work - small parts have a way of vanishing when they drop.

http://www.youtube.com/watch?v=o5cxBMDezuU
 

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jayrdubya

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Jun 1, 2009
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Re: '84 Evinrude 115hp V4 VRO high RPMs, loss of thrust at above 2/3 throttle

Thanks for your info. I guess that's what I meant, a spun hub on the prop. Just one question for the test though...do I have to take it on the water to test the mark and see if it spins, or can I do it in the driveway with the muffs and waterhose?
 

crxess

Chief Petty Officer
Joined
Apr 30, 2009
Messages
559
Re: '84 Evinrude 115hp V4 VRO high RPMs, loss of thrust at above 2/3 throttle

Has to be under Load.

If it is spun bad, you can place the motor in gear, NOT RUNNING, ignition off and bounce on one side of the prop. Recheck the mark. if it moves its slipping.

99% sure your prop is bad.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: '84 Evinrude 115hp V4 VRO high RPMs, loss of thrust at above 2/3 throttle

You will need to test it under the conditions where it slipped before. If it is spun, it will only get worse over time.
 
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