Prop shaft extravaganza!

[Ericelgin1]

Went skiing this morning and after a fellow skier was down I circled around when all of a sudden I heard a thunk....the boat came to a stop I opened up the motor cover and noticed that there was no shaft coming out of the coupling on the transmission.  I had a few extra set screws in my tool pouch so I lined up the shaft and pushed it back together and tightened it up.....well when I drive the boat now there is terrible vibration, I believe it is from where the prop slid back and hit the rudder and got damaged.  I can see and feel damage to at least one blade and probably more.  Is a damaged prop enough to cause some pretty descent vibration?  The rudder seems to have a little play In it but I don't know if it is more than was there prior to today's fun event.  How much is acceptable?  I want to get a new prop while i send this one to get reworked any suggestions? My boat is a 1984 18 foot skier.

[phil]

Yes, a little ding in your prop could cause serious vibration. You'll need to get your prop fixed/replaced and then realign the transmission shaft.

[daveo]

prop damage can cause alot of problems DONT RUN THE BOAT! the vibes can cause damage to tranny also you need to check the rudder and port for damage . your steering problems  may have just been from the prop damage. It can affect the steering because the damage is causing some cavitation

[Ericelgin1]

I drove it straight to the trailer, that is when I noticed the vibration.

What are some prop options for that boat? Are there a lot of choices as far as, better pull, smother ride, higher top end etc.etc. 

Thanks a million!

[Midskier]

Eric, I have also responded to your e-mail

with the boat on the trailer you'll need to inspect the damage (obviously)

you will also need to ensure the shaft is not bent, if it is it gets replaced
and while it's out replace the strut bearings too

if it's straight and most likely it will be........ do one of a few things
take the prop off and get it fixed, I assume it's an almost original nibral 3 blade
sandcast prop........ depending on how bad it is it will determine if it is repairable or not

any dings dents, tears, or other damage 2 the edges is usually repairable ,
any damage blade twist, folded over etc nearer the hub may be a paper weight / non repairable

how do you use your boat?

wakeboard with heavy ballast?

wakebaord never ballast

slalom ski in the course @ 32-36 mph

barefoot

pull tubes

etc

maybe it's a little of all the above and if so we need to find the best compromise because one
prop will not do all but some will do most , better than your original prop

additionally what state of tune is your engine?
new cap rotor wires plugs? timed properly / power timed?
what is your rpm @ WOT (wide open throttle)

Dan T

[RonT]

I would be more concerned with why the shaft "fell out" while going forward. I would expect shaft/coupling damage and prop damage, the shaft may be straight but something is wrong at the coupling end. If it an older boat with the straight cut shaft I would guess the shaft has been out of alignment for a long time & has destroyed the keyway, keyslot, and bore. Remember when going forward the shaft is trying to push the whole engine forward. Usually when a shaft comes out it is when you are in reverse.

[Ericelgin1]

Thanks guys,


The shaft came out when I went from skiing speed to neutral pretty fast as I was getting ready to pick up a skier.  I assumed that the rapid slow down pulled it out..........not enough?  When I looked at the shaft and coupling I noticed the hole for one of the set screws was buggered up and the screw would not go all the way to the shaft.  While on the boat I put a new set screw in to get back to the trailer,  when I got home I pulled the shaft back out and ran a tap through the other set screw hole.  I put the key in another direction  when I put it back and it felt tighter than when I put it back the way it was originally.

The damage on the prop appears to be at the edges of prop so I think a repair might be in order.
The boat is mainly used for waterskiing 34 mph
As far as the tune of the engine I don't know I just bought the boat but it starts and runs and pulls skiers.  I was hoping to start making improvements to engine when I dewinterize next spring.  I am defiantly a rookie when it comes to the motor.

Thank you all for your advice. I feel like I am a member of an American Skier Self help group!     

[Joel]

You are...      I learn a little something everytime I log on... and I'm on here every day    Theres a couple of threads on here about winterizing your boat.  May wanna read up on it before it gets too cold.

Welcome aboard!!!

[Ericelgin1]

Sent my prop to prop shop and the guy does not think thank that he can fix it.........anybody know what a good prop for an 1984 18 foot skier?  I mainly ski at 34 mph with only one or two people in the boat.

Y'all are rad.

[Midskier]

WOW, can't fix it........ I'll be around tomorrow I've got a couple of ideas for you
Dan T

[amskierLDFWI]

I have 3 props for my 83, I just had the entire thing rebuilt and had a new shaft put in, it is watercooled too! I can post some picks in a few weeks when I get back to the lake

[Ericelgin1]

Thank you that would be great

[Ericelgin1]

Well hopefully this is the last instalment of prop shaft extravaganza! Got an almost new prop from Dan and it seems that my problems are solved!  My top end speed was around 5 mph faster and the boat seemed smother.  The thing pulled like a grand canyon donkey!  Also went through a slalom course for the first time.......there is a good chance that I am addicted. 

Thanks again folks!

[Joel]

Great news!!!  Glad you got her back together and running smoothly.

[chrisheile]

Oh boy.  First pass through the course.  I was soooo excited.  It does become addictive.  Congrats.