Snapped the prop shaft..

[Infomaniac]

Ok first major failure for the Cougar.
Snapped the prop shaft off inside the prop. Looks like at the first thread. I did strip out the coupler the first time I hit the throttle wide open (3 years ago)
Took a chunk out of the rudder. Did not touch anything else.
Counting blessings, had my son in the boat.
Was crusiing about 40 hit the throttle hard to get the final blast before reaching the no wake zone. The boat took a set - accelerated like crazy and then "Zing"
I looked down - it was still in gear - let it idle long enough to look at the fire coming out of the zoomies. (about dark) got towed the final 100 yards to the ramp.
Will take pics tomorrow.
The boat did not even know something happened as it slowed to a stop. Who says v-drive tunnels are death traps?
Very strange that it happened to a friend's hydro 1 week ago tonight. We were going to race - he put it in gear and nothing happened. Snapped his shaft inside the prop. A diver found his prop in about 45 seconds tonight.
Not sure if I want to find my prop after hitting the rudder.
Will start ordering parts tomorrow.

[GofastRacer]

Damn that sucks, sorry to hear that glad nobody got hurt!.. frown

[superdave013]

Who are you getting the shaft from? I've been shopping around and so far V Drive Tom is in the lead for me.

[Rexone]

That sucks Info and it sounds like you got off lucky too. We should have Aquamet 22 in stock if you need just give a call.

[Lookin for Liquid]

Sorry to hear the news but it sounds like it could have been much worse. If you need help on the rudder, let me know as we have them in stock.
Dan
Canyon Marine
[ July 18, 2003, 06:40 AM: Message edited by: Lookin for Liquid ]

[Snowboat]

Wow, that's scary. Glad you're alright. I hope its because there was something wrong with the shaft rather than having too much HP for a 1" shaft. Soooooo, what are the requirements for high HP, light weight boats? Don't some SS boats run a 7/8" shaft?

[hottrodder]

Most old marathon boats and todays ski race boats run 1 1/8".

[V-Drive Tom]

There is no set rule for how much you can over power a given prop shaft diameter.(I know,DUH..)
If you are going to run a blown alcohol engine,AND you run your boat at the races, along with lake racing, then I would replace the shaft EVERY YEAR.
If you don't run the boat much then longer.
There materials out there that are COPIES of Aqua-Met grade material. They work OK but are not AS good.
Sometimes, a lesser grade (AQ17 or19) gets sold as a grade 22.(not good!)
A true AQ-22-one inch shaft will take alot of abuse, but you have to check them.(dye check)
Thats why you see all of the red dye and white powder on SHAFTS and PROPS at the boat races.
The 7/8 shafts that the circle boat guys are running is definitely a test of the limits.(my opinion)
I sell true AQUA-MET material,at a great price.
A new prop shaft is good for piece of mind and safety. Smart money spent...TOM.. smile_sp

[Snowboat]

Tom, I have no idea how old my shaft is. Do you check the grade by Rockwell hardness or another way?

[Infomaniac]

Expect a phone call today Tom.
My shaft was only 15 years old.
Maybe the newer material should last twice as long? :D

[hbhallett]

Info- glad both you and your son are ok! I sure am glad you are both alive and well as I would surely miss your credible replies and insight on this board. I for one always appreciate your suggestions on technical issues without the bs. Both you and Fiat are the only reason I follow this forum.

[Infomaniac]

Here is the damage. Rudder struck 3 times. Bent the shaft.
Prop shaft had a crack right at the base of the ramp in the key way. Black marker at the end of the strut barrel.
http://www.***boat.com/image_center/data/506/211Broken.jpg

[126driver]

I broke one once at about 2/3 track. Zinged the hell out of the motor but the prop never touched any part of the boat. On the other hand, my dad broke a propshaft back in the day and it hit the rudder and corkscrewed him in. eek! Heads or tails, it's all about mojo when something like that happens.
[ July 18, 2003, 05:51 PM: Message edited by: 126driver ]

[SK48]

I buy new shafts for the Biesemeyer, every couple years, and then the old flatbottom shafts become shorter and go in my tournament boat. It makes it easier to justify replacing them.

[Lookin for Liquid]

Two things come to mind in this situation that possibly might help others and I am not saying this would have been the cause but I do feel they are important to address after looking at the pictures. The first is that the propellor barrel should not be more than one quarter of an inch past the strut. The farther it is back, you are asking for a leverage factor that is not capable from a material that is designed for torsional twist. The second is that the prop should seat on the taper evenly without hanging on the key unabling it to slide all the way forward. Install your prop on the shaft without the key and measure the gap to the strut and then install the key and do the same. It should not vary and if it does the key is not letting it seat on the taper and the interference of the key must be corrected. I very rarely see a shaft broken in the propellor hub. They will usually break just ahead of the hub before the strut or crack at the keyway out of the V Drive if the keyway in the propshaft is exposed out of the coupler. Sorry to ramble but I hope it might help someone.
Dan
Canyon Marine

[Infomaniac]

Lookin for Liquid:
Two things come to mind in this situation that possibly might help others and I am not saying this would have been the cause but I do feel they are important to address after looking at the pictures. The first is that the propellor barrel should not be more than one quarter of an inch past the strut. The farther it is back, you are asking for a leverage factor that is not capable from a material that is designed for torsional twist. The second is that the prop should seat on the taper evenly without hanging on the key unabling it to slide all the way forward. Install your prop on the shaft without the key and measure the gap to the strut and then install the key and do the same. It should not vary and if it does the key is not letting it seat on the taper and the interference of the key must be corrected. I very rarely see a shaft broken in the propellor hub. They will usually break just ahead of the hub before the strut or crack at the keyway out of the V Drive if the keyway in the propshaft is exposed out of the coupler. Sorry to ramble but I hope it might help someone.
Dan
Canyon Marine Dan - Thanks
There was only 1/8" of shaft exposed between the prop and strut barrel.
V-Drive Tom mentioned that it could have been a key stock material issue in addition to prop fit.
I will check the prop fit very close. New prop and new shaft.
This is 2 in one week around here broken inside the prop.
The crack was easily visible. Could have been prevented.

[wfodude]

Now get your butt to church info...you owe someone bigtime :D
[ July 19, 2003, 03:33 AM: Message edited by: wfodude ]

[Lookin for Liquid]

Ron.....Rudder is packaged and shipping Monday Red Label. Good Luck with everything else. I am very positive Tom will take excellent care of you.
Thanks Dan
Canyon Marine

[Thunderbutt]

Info, I'm glad you and your son are alright. Horse power does funny things, and God knows you have it. I would also check the strut for a split, maybe an 1 1/8 prop would be better, rudder to. I finly got into your web sits, (Very Good) Dan is right on how to install a prop, and I tell all of my freinds with transmissions never put it in reverse gear after installing there prop, go forward first. Good luck