1984 OMC stern drive problem

[Cliffy]

I have a 20' Chapparel I/O with a OMC stern drive and a 305 GM. It seems to engage in gear but does not spin the prop. Sometimes the motor will be under load but it will not turn the prop. If I spin the prop by hand while in gear, it grinds a little and feels like it wants to work but does not. Can anyone please tell me what the problem may be and how to fix it? I am going to get a service manual from the local library and hope that it can help.<br />Thanks,<br />Mike

 

[Boatist]

Re: 1984 OMC stern drive problem

Cliffy<br />Need to know for sure motor type, I think a stringer 400 or 800 but close to cobra series. Also HP.<br /><br />I think it is a stringer and if it is it is a very common problem. There is a small shaft in the outdrive that drives the water pump and drive shaft. This is a spline shaft and over time splines wear to point where the splines slip. This is a problem on the stringer models only not on the cobra. If that is the problem then will have no water from impeller to the engine and no drive shaft rotation. If you check the water pump indicator that sprays on ball gears will have no output while in the water. May get some on the muff. Parts and labor around $800 to $1000. Not a easy shade tree mech Job.<br />Good luck.