Prop spin

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Mar 17, 2023
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2000 evinrude 90 that with engine off and in gear prop will turn about 35 degrees in each direction. I found this while trying to diagnose why boat is acting like prop is spun. Took off prop and shaft does same thing. With high rpm boat will not accelerate. Any ideas
 

QBhoy

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Are you saying that when in neutral and engine off…the prop shaft will not allow you to rotate it 360 degrees?
 

jlh3rd

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Jul 10, 2017
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his shaft is turning 35 degeess in both directions with the prop off, in gear., engine off....not good...
 

racerone

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Dec 28, 2013
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Check gear oil for metal bits.---Pinion gear teeth could be stripped.------Those lower units are NOT robust in my opinion.-----But 35 degree rotation is in fact normal.
 

QBhoy

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You’re not a man I’d question on things like this racerone. I have the suspicion that you know something I don’t about this particular engine maybe ? I know it’s not normal on my outdrive and my outboard boats with Mercury and mercruiser. Sounds like there might be a reason for it on this engine, after reading what you’ve said ?
 

QBhoy

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Ok. Just read your first post again. Racerone is correct if it’s in gear. Totally normal to see what you have in the video when in gear.
Got to be the prop hub bushing or kit that’s failed…unless maybe it’s to do with engine set up for height and trim use ? Tell us more about the issue. What exactly is it doing or not doing ? What exactly is it doing when you say won’t accelerate from high rpm ? Spun prop usually will let you get moving along slowly at low rpm at a few mph…any more power put through it will make it give up and not transmit the power through the prop. Certainly won’t usually let you get on plane with hard acceleration usually…unless it’s only just holding on and on the verge of going. Are you sure it’s got nothing to do with the engine height or trim position and the prop is losing grip of the water and venting ?
 

Texasmark

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Dec 20, 2005
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If its the prop hub to casting slipping it's very easily diagnosed. Just scribe a line from the innermost piece of metal (spline) out to the outer most piece of metal (barrel) and take it out and run it. Remove the prop and look at the line. If intact, gear problem....if distorted, hub problem.
 

jlh3rd

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I guess mercury and evinrude are different.
I don't have anywhere near that slack..
 

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Texasmark

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I guess mercury and evinrude are different.
I don't have anywhere near that slack..
I don't in R either, just a few degrees , obviously N spins freely. In F since the gearbox contains an overrun clutch, which is nothing more than a gear ground in a saw toothed configuration such that CW, in the overrun position, turning the prop causes the teeth to slide over the ramp causing the prop shaft to protrude slightly going up the ramp and falling off the vertical area it goes back in. Selecting the CW position, where the vertical sections of the clutch line up, it depends on where you stopped on the ramp as to how far the prop will turn before the verticals line up and it stops turning.
 

racerone

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Poster will try another prop or report what was found with the gear oil I think.
 
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