Twisted Prop Shaft
 

I have Bravo1's with Upgraded IMCO gears/ propshafts that are 5 hours old. Stbd was running rough on our first day out Memorial Day Sunday, so we pulled the boat to inspect.
Prop shaft twisted!!! Never hit anything, the prop is perfect.
Never free-revved, since the new gears since the new gears were installed.
Any explanations out here? Any known Imco warranty on their shafts/gears?
I am baffled worse than when I found out the truth on Santa...
Carder

2 years ago 2 buddies had a shop tear down and service their drives. In just an hour both of them had prop shafts seize in the drive and sheer off dropping the prop in the river. Don't remember the exact reason, but improper assembly of the drive was the cause.

what are you running for engine's, hp, gear ratio, prop size, where they the larger prop shafts or stock size? possibly got a soft shaft from factory, call Imco, I'm sure they can help.

Running HP500's, about 585HP, Bravo1's, 1.5 gears.
Prop shafts were the std. B1 size, but with the IMCO hardened lower gears/ propshaft. I also think I got a soft one.
Here's the carnage:

I would get a hold of imco, that;s not right.

Plus don't run it. Its possible to lose the prop.

Carder,you have the worst luck. It took me 6 years of running a max worx small prop shaft and 350 hours with 620hp then 750 hp then 950hp before finally breaking a shaft after putting almost a 1000 ft lbs of tq to it with a full size maximus 5 blade on it. Even then it broke where the shaft went in the gear and prop splines STILL looked pretty good. I'm sure it must be defective. No prop damage? I tore up my labbed 30 pitch on a rock at the end of last season driving out of the channel at your marina,Smitty

Smitty,
Bad luck is getting expensive beyond belief. I sent IMCO the photos yesterday, we'll see how they back there stuff.
Sorry to hear about the prop @ Linwood Beach Marina, they have been dredging and pulling rocks out, but you still have to be on plane before the bouys end... I prefer to get it going by the seawall.
Carder

I'm going to avoid the linwood marina in the future,I haven't wrecked a prop in 7 years until last year,usually your safe if you idle out a channel past the buoys,thats where I started seeing a little more depth and as soon as I started going on plane I thought I must have got out of the channel because it got REAL shallow quick.
Good luck with imco,even though you only have 5 hours on your drive and 500hp its going to be hard to get them to believe it,I hope they do something for you. If you ever decide to do something different with your drives I can put some max worx shafts in for you,Smitty

i HAVE A SET FOR RIGHT NOW ON EBAY MAY SAVE YOU SOME MONEY.
http://cgi.ebay.com/ebaymotors/ws/eB...253232378&rd=1

So far, it is clearly my fault that the stronger prop shaft twisted... even tho the weaker stock B1 shaft did not...
...evidently I must have either free-reved it, or seized the engine, sometime in my sleep....I am so sorry.
Sales are everything, support is Bull ****.

I bought a "new to me boat", had the drive rebuilt and had found the stock B1 shaft was twisted and I asked the mechanic why? He said the most common answer is jumping the boat and not pulling off the sticks.

for the 5 or 6 hours on the drives, we have been taxiing around our 6 year old... the boat doesn't go out of the water.
Carder

so is imco giving you the run around, I would hope not, A lot of there customers are on this site, and there looking for a good product that is backed up by what they claim.

No positive responses from IMCO to date....hmmm

Prop Shaft
 

OR YOU GOT THE SHAFT ! more scrap for UNCLE TYLER ! just two more weeks and I WILL HAVE MINE UP TO GET WORK DONE THE BOTTOM has been a night miror :cool: GOOD LUCK WITH YOURS !:ernaehrung004:

Dude I just twisted one of mine this weekend on my new imco shortie. Blow up the upper gear set!!! Standard bravo shaft. Said I must have missed on the sticks.

What props are you using? I would think at 585hp a std. B1 shaft should live.
Time for the 1 1/4 XR's

Sounds familiar... The response to me was "what part of no warranty don't you understand"

I had the same problems when my brand new IMCO Extreme SC's blew up one right after the other with approximatlely 15-20 hours on them.... One was bad enought that I had to buy a new upper case. They said my engines were producing "torque spikes" (700 hp, drive is rated to 800) and that I was shifing them into gear at too high rpms (950)....

I told them to go scratch, had them fixed and sold them a few months later. I nick named them Crapco.. :(

http://forums.boatfreaks.org/showthr...highlight=imco
http://forums.boatfreaks.org/showthr...highlight=imco