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WBcrash

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Have a 2007 20hp 4stroke tiller at high throttle seems to break down or slip but is fine at lower speed what could this be
 
Just put the outboard in gear with engine off. Wear some gloves and grab two blades and try to turn the prop. Any... ...ANY movement of the blades indicates the hub is bad.

Note: when shifting an outboard that's not running, you need to be slowly rotating the prop as you move the shifter. It doesn't matter how fast or in what direction. Just so it's moving a bit as you shift. This prevents the clutch dogs from hanging up and that prevents the possibility of bending or breaking a shift linkage component.
 
jgmo said:
Just put the outboard in gear with engine off. Wear some gloves and grab two blades and try to turn the prop. Any... ...ANY movement of the blades indicates the hub is bad.

Note: when shifting an outboard that's not running, you need to be slowly rotating the prop as you move the shifter. It doesn't matter how fast or in what direction. Just so it's moving a bit as you shift. This prevents the clutch dogs from hanging up and that prevents the possibility of bending or breaking a shift linkage component.
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Thanks for your reply I did as you said and there is some movement. This means that even this brand new prop is spun? Never been grounded or any type of damage has happened is it still possible?
 
WBcrash said:
Thanks for your reply I did as you said and there is some movement. This means that even this brand new prop is spun? Never been grounded or any type of damage has happened is it still possible?
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Make sure your turning the prop isn't causing the drive shaft to turn the crankshaft.
 
If you can turn it by hand, it is spun. N.E.W. stands for;
Never Ever Worked.

Where did you get the prop? They might have some splainin' to do.
 
Just to be clear....
There will be a small amount of "gear lash" or movement in the transmission that can easily be taken up by hand. Then, trying to force the prop past that point, there should be NO movement if the hub is good.
Is that what you're finding?
 
WBcrash said:
Have a 2007 20hp 4stroke tiller at high throttle seems to break down or slip but is fine at lower speed what could this be
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How long have you owned this and did it always slip?

A friend has a pontoon/deck boat with a Johnson 150 and it did this- no real indication that anything internal has broken, neither of his hubs are broken and it happened with the new prop- it seemed to be an issue of weight distribution in that case.
 
jgmo said:
Just to be clear....
There will be a small amount of "gear lash" or movement in the transmission that can easily be taken up by hand. Then, trying to force the prop past that point, there should be NO movement if the hub is good.
Is that what you're finding?
Click to expand...
Yes
 
If the prop is new, it may have been stored for a long while and, possibly, in a manner that could have caused the rubber bushing to deteriorate such as direct sunlight.

Or, it simply could have been improperly assembled to begin with. Very hard to say.

Sorry this happened to you.
 
A prop with a rubber hub will always have some movement doesn't mean its bad. Unless the hub is spun REALLY bad you will never turn it by hand. Put a mark across the hub of the prop and run it if the marks are not lined up when you are done the hub is spun.
 
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