Alpha One jumping out of gear

[brettski]

Hey guys, I got a 94 Invader with a 5.7 mercruiser Alpha One. when i put it in gear it locks easily but as soon as i put a little power to it, it jumps out? it does the same in reverse. this boat sat for about 4 years in a shed... would that contribute to the problem???, maybe corrosion or rust or something? The boat has never seen salt water if that makes a difference. thanks guys, any help would be great!!!

 

[Bondo]

Re: Alpha One jumping out of gear

Ayuh,... That's quite Unusual, because of the back-cut gears,...
Probably otta start by pulling the drive, 'n inspecting the shift linkages/ cable...

 

[dn010]

Re: Alpha One jumping out of gear

Check the lower shift cable adjustment, you can also disconnect it and try it by hand to see if it is binding etc.

 

[Don S]

Re: Alpha One jumping out of gear

The shift cable is probably binding and not allowing the drive to go all the way into gear. The jumping out of gear also causes the shift dogs on the gears and shift clutch to round over very quickly.
You also need to check the shift interrupt switch and see if it is working. Many times, owners disconnect the switch as the cable gets stiffer and the engine keeps dieing when shifted.

 

[Fishermark]

Re: Alpha One jumping out of gear

as soon as i put a little power to it, it jumps out?

Are you sure it is actually jumping out of gear? Almost sounds more like a prop hub slipping. What is happening when it "jumps out of gear?"

 

[jdmac]

Re: Alpha One jumping out of gear

When the "jumping out of gear " occurs, is there an adutible clunk clunk clunk noise? If so thet is the clutch dog ratcheting past the gear ramps. Not good. If you do not have a noise but rpm increases & you do not have propulsion, Then Fishermark is correct you most likely have a hub slipping in the prop.

 

[Brentathon]

Re: Alpha One jumping out of gear

I thought my Alpha was jumping out of gear.........it turned-out to be a missing diffuser ring on the aft end of my prop hub, which allows the exhaust to get sucked into the blade area, and you lose virtually all thrust.

 

[brettski]

Re: Alpha One jumping out of gear

hey so onces shes in the water and ready to leave the dock for example, i go at idle for a bit and as i slowly put the power to it it just jumps out and the engine stays revved up....... then i bring er down to neutral and try again it does the same thing, even if i put the power to er quick once shes in gear....thanks!

 

[brettski]

Re: Alpha One jumping out of gear

and also it wants to quit running once in gear in some cases, im not sure if thats just a carb problem or what it could be....

 

[Don S]

Re: Alpha One jumping out of gear

Try a different prop.
If that cures the jumping out of gear problem, your stalling may be due to a stiff shift cable that holds the shift interrupt switch engaged when you put it in gear.

 

[Fishermark]

Re: Alpha One jumping out of gear

If you don't have a different prop, (and you really should keep a spare! ), then you can put a mark on the outside of the prop and the hub. Then use the boat and check your marks. If they are no longer aligned, then your prop is bad.