'91 25hp 2 stroke merc lower unit

Chris724

Recruit
Joined
Dec 7, 2014
Messages
3
Whenever I push the throttle down it just revs up and doesn't go anywhere. It transfers into reverse and foreward but never goes faster than like an idle. I've been able to take the lower unit off and I was able to get the water pump off then I got stuck. I'm trying to check the bearings.
ce56286542c1631cd48bc235823ad712_zps09a4acb6.jpg
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,884
Does the shift linkage move?
Does it actually go into gear?

Since you are moving at idle speed, it seems like it must be going into gear.

Like the others said, probably a spun prop hub, the rubber bushing inside the prop.

Not sure what the little part is you are holding, or where it goes.
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
The small part you are holding looks to be the adjustment stop for the lock dog for the flywheel. It is so the motor can not be started while the motor is in gear, and the lever above in the picture is where it should be connected to.
If the boat moves at all fwd. or rev. then I go along with the spun prop as the rest have stated. With the motor off, you can see if the prop will spin whit the motor in gear by trying to turn just the prop. Otherwise make a mark across the end of the prop shaft and one on the prop and run the motor in gear on thee water . When done see if the marks still are lined up. If not then time to rebuild the prop with a new hub, or get another new prop. JMO
Oldman570
 

Chris724

Recruit
Joined
Dec 7, 2014
Messages
3
Thanks ill look at the hub. That peice is exactly what u said. It's part of the recoil starter assembly. All the linkage seems fine except that broken peice. The boat will push at like 1 mph just from being in gear. But when I give it any gas at all it just revs up and does nothing.
 

quicktach

Petty Officer 1st Class
Joined
Aug 24, 2012
Messages
394
Sounds like your prop needs replacing. See if you can get a loaner to try under load before buying.
 
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