Prop delema

[eracer]

Im running a 235 omc, i have several props that i use. It has been since 1999 that i have been able to resume boating fun.
I had on the 15x17 and made the switch to the 13.25x25 shooter prop. Somthing in my mind said to find the smaller back washer to put behind it, i couldent find it so i put it on. The boat seemed to perform better than i remember in hole shot and top speed.

At the end of the day i was cleaning up the boat and down in the bilge pump hole was the smaller back washer that i thought i had.
So i took off the shooter and and put the washer behind it and 1 more small detail of lifes problems was off my mind.

The next day out on the lake i fired it up and put it in gear and right away it felt a little different, got out in the clear and took off and the hole shot was bogged feeling, the midrange burst of power felt softer. So now i am engulfed in thinking what the hell.
I didnt do any thing except put that washer on the back of that prop.
So about midday i pulled off the prop and took out the washer, put the prop back on and the boat perfomed excellent.
I have always used the large washer with the 3 blade props and to the best i can remember i have always used the smaller washer with the shooter.

What is going on with the performance? Why does it work better with out the washer? I am going to have to use the washer or damage the prop right?? Is there some special work i need to do to the washer. Run the nut loose. I dont like the performance with the washer in place.
Please help.
Kent
:confused:

[AnthonySS]

Dear E,

Quite simply the inner thrust washer is not interfering with the exhaust gases that are flooding your prop, allowing it to rev up quicker, therefore resulting in better holeshot.

We have achieved a similar result by using small inner thrust washers on various props. You have to make sure the thrust washer dia does not exceed the prop hub diameter...then you get better "wind up". Otherwise the wider inner thrust washer deflects the exhaust gases out to the side instead at the prop.

However on Merc's you got to run the inner thrust washer...I would think the same on your OMC otherwise nothing is keeping your prop from wearing on the gearcase housing....thats going to hurt eventually.

I suspect you have the wrong inner thrust washer! Cause I just spoke to FlatOUT (omc expert) and he says the proper thrust washer seats perfectly on the prop hub!

What you could do is take the inner washer you have and have it turned down by a machinist to the smallest possible dia...That should give you the best of both worlds.

Anyway let me know if this helps any?

[Flat Out]

Big E, I spoke with AnthonySS and perhaps I'm confused. The thrust washer should go on first then the prop followed by a brass splined washer. The nut threads on, tighten the nut ,place the castle cage on the nut than insert the cotter pin. The only thing that goes on the prop shaft before the prop is the thrust washer. This carries the load of the prop at the gearcase and the splines carry the load at the rear.The machined face of the thrust washer should fit right into the hub of the prop on the gearcase side. I hope I'm not confused and this helps.:cool:

[eracer]

Flat out and Anthony SS:
I already have the small thrust washer behind the prop, it doesent interfere with any thing, i use the large thrust washer with the other props that i have. If i take that small washer out there is a noticable difference.
So what else could be going on.
Kent

[MennoNetherlands]

your prop reliefs exhaust behind the prop without te washer
it works like a over the hub prop and slips

[eracer]

What i think is going on with the shooter is that i have discovered that it likes to run a little bit closer to the gear case, perhaps i could experiment with several thrust washers with different id's to locate the prop a little further back.

Any body running a shooter take the washer out and give it a try.
Ill bet you that it works better.
Thanks for any help.
Kent