Prop Question for 76 I6 115hp

[JssCop]

I bought a new 17 pitch prop. Put it on and it ran good but then started running bad. When I checked the prop out when I was done the prop had fell back into the lower unit housing and I could move the prop forward and backwards betwee 1/2 inch and 1 inch. It was also cutting into the blades. So I put the spacer on the back of it and now it has about an inch between the back of the prop and the housing. Does the spacer press onto the shaft tighter to make it sit more flush or do I have a larger problem? Thank You any replies appreciated.

 

[Chris1956]

Re: Prop Question for 76 I6 115hp

The spacer (actually called a thrust washer) fits tight to the taper in the propshaft, near where it goes into the housing. You need the correct thrust washer for that prop and motor. The prop should have an inside hub that is a bit smaller than the gearcase OD, and should recess about 1/8" into it. It sounds like you either have the wrong thrust washer, or have it on backwards. Look for the tapered hole in the thrust washer, and see that it fits the tapered part of the propshaft.

 

[79Merc140]

Re: Prop Question for 76 I6 115hp

Sounds more like he did what my brother did to me once. Changed props and didn't put a thrust hub on and as I was pulling him on ski's, the prop slowly started to eat it's way into the lower unit housing. Once that happens (Depending on how far it chewed it's way). Put on the original prop with the thrust washer and see if it will go to WOT (Wide Open Throttle) without cavitating. On mine, after I took off the prop my brother put on and put the old one back on, the exhaust would push out and around the outside of the prop just after getting up on plane. I ended up having to get a new housing and have my gears out of my old housing installed into the new one. It was about 400.00 back in 1985.

Hope this helps.

Craig