'77 Evinrude 115 just revs up when trying to get on a plane

lance129

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Oct 10, 2011
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i bought a 1978 16' checkmate with a 1977 115 evinrude on it about a month ago, ive had it out every weekend so far and its ran great but last weekend i was out and hit something that tore my prop all up . after that it wouldnt get on a plane, itd idle fine but when i went full throttle it would juts rev way up and slow down. so i went home, changed the prop and took it out this weekend...same thing happens, it just revs way up and slows down, it still wont get on a plane. some people have told me it could be a spun hub, but im not sure if it would be that after i changed the props out.... any ideas???
 

etracer68

Ensign
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Oct 11, 2009
Messages
906
Re: '77 Evinrude 115 just revs up when trying to get on a plane

Was the prop a SS prop? You may have damaged something in the lower unit. Alum props forgive a bit more when you find them underwater things that dont move to well.
 

lance129

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Re: '77 Evinrude 115 just revs up when trying to get on a plane

No, it was an alum prop, whatever i hit took one of the blades completely off. i didnt even feel the motor hit anything, all of a sudden it just started running really rough, but the boat was still on a plane and it ran fine for a few minutes until i slowed to an idle again and thats when it wouldnt get back on a plane
 

boobie

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Re: '77 Evinrude 115 just revs up when trying to get on a plane

If you're sure the hub in the other prop you put on is okay, you might have some G/C probs.
 

nwcove

Admiral
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May 16, 2011
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Re: '77 Evinrude 115 just revs up when trying to get on a plane

drain the lu, and look for shrapnel.
 

lance129

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Oct 10, 2011
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Re: '77 Evinrude 115 just revs up when trying to get on a plane

alright guys thanks for the help, ill check the hub on the prop i just put on, and ill also check the lower unit fluid tonight.
 

lance129

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Re: '77 Evinrude 115 just revs up when trying to get on a plane

just drained the lower unit fluid...or should i say water. about a cup of water came out before about a cup and a half of fluid came out... i expected to see a ton of metal shavings but there was a very little amount. what have i got myself into now?! guess im gonna refill it with fluid and try it again, if the lower unit is shot the damage is already done right?
 

iwombat

Captain
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Jul 12, 2006
Messages
3,767
Re: '77 Evinrude 115 just revs up when trying to get on a plane

Most LU leaks are caused by re-using the nylon washers. Make sure to use new ones every time you change fluid. My money is on a spun hub.
 

lance129

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Re: '77 Evinrude 115 just revs up when trying to get on a plane

is there a way to tell if a hub is spun??
 

boobie

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20,826
Re: '77 Evinrude 115 just revs up when trying to get on a plane

Mark the prop and the hub with a magic marker or scratch awl. Take it for a ride and see if the lines get out of alignment. If they do the hub has spun.
 

lance129

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Oct 10, 2011
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Re: '77 Evinrude 115 just revs up when trying to get on a plane

alright, will do. thanks!
 

lance129

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Oct 10, 2011
Messages
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Re: '77 Evinrude 115 just revs up when trying to get on a plane

the hub on the prop i had put on ended up being spun and aparently the blades had no "cup" to them so my mechanic said it cant grip the water so it would just rev up... figures! so im picking up a refurb'd one tomorrow on my way home from work and hoping for the best!
 
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