77 Chrysler 75hp OB-Shifts into gear hard-Jerks boat

argeldeggy

Cadet
Joined
Feb 25, 2010
Messages
9
Hi Everyone,

I have a 77 Chrysler 75hp, I've been having issues with it when shifting forward or reverse. It shifts into gear pretty hard and jerks the boat. What could be the problems? I've looked at my Clymer's Shop Manual and have not found any trouble shooting on this issue. Please Help.

Thanks in advance

Argel
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: 77 Chrysler 75hp OB-Shifts into gear hard-Jerks boat

Don't know your specific motor but a clunk is normal on a force. Sort of like an older Harley. Jerking the boat is unusual. Are the RPM's too high?
 

argeldeggy

Cadet
Joined
Feb 25, 2010
Messages
9
Re: 77 Chrysler 75hp OB-Shifts into gear hard-Jerks boat

I will check the idle RPM, how fast should the RPM be? Thanks for Reply. The other day It clunked into reverse so hard I saw the motor jump back and then forward which jerked the boat. Going into reverse clunks into gear harder than forward does.

Thanks again for the reply..

Argel
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 77 Chrysler 75hp OB-Shifts into gear hard-Jerks boat

If the idle speed is correct: 700-750 in forward gear, in the water, about 1000 in neutral then

Check the distributor drive belt tension and check to see that the distributor moves freely. Either a too tight drive belt or a dist. that is binding will cause an interference in the shift linkage and the engine either will not go into gear, go in very roughly, or not come out of gear. Sometimes all three.

The drive belt should deflect about 1/8 inch when a .010 feeler gauge pointed like a finger is pressed in the middle. That is, the belt should deflect that much before the gauge bends.
 

argeldeggy

Cadet
Joined
Feb 25, 2010
Messages
9
Re: 77 Chrysler 75hp OB-Shifts into gear hard-Jerks boat

Thanks for the info, In neutral RPM's is set at almost 2000 rpms. Ill see if changing that will make a difference. I think this is the prob, Ill keep you posted.

Thanks again for the reply

Argel
 
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