Stuffing tube splitting
 

Everything is lined up perfectly between the collet and flexshaft , there is a little bit of play at the prop , each time I run the boat it seems to split a little more , any ideas...

Looks to me like there is some whipping going on, be it due to an off-center bore in the collet or something with the flexshaft. This, to me anyway, is indicated by the "belled" end of the tube. If it was running straight, there shouldn't be any deforming of the tube. What I would do is install a straight piece of rod into the collet and tighten it down enough to hold it. Next, take an indicator dial and set it up to ride on the rod. Now, slowly spin the engine over and watch for runout. If you see much in the way of dial indicator movement, that would be your problem

What he said. It appears to be a clutch setup so there has to be some wobble in it. It might be as easy as pulling the engine over slowly to see if the collet is moving around. To me, the clutch is very suspect.

Soft mounts will let the engine move around too much. Also how much tube is unsupported behind the collet?

If you look closely, the tube goes through the bottom of the boat at the top of the picture and has FG over it just past the crack. I don't think support is an issue. Since we can't see the engine mounts, I have to agree, there could be an issue, as could too small of tubing for the size of the flex cable. I still tend to think the cable is whipping due to either a mis-aligned bore on the collet or, as Ron said, play in the clutch assembly

As a option:
Stuffing tube is a bit close to the coupler there is no teflon present heat is building up there too.
I would cut off the bad section off and run out enough teflon to go out past the brass tubed by 1/4in.
For sure check / tighten up the engine mount assembly things can get loose over time.

http://www.rcuniverse.com/forum/atta...mentid=2203506

This is exactly what I was thinking of doing there is no teflon liner now , and I will also check the clutch there seems to be a bit of vibration from the clutch . Thanks for all your great suggestions...

the bearing in the clutch housing is shot. this will cause the collet to run off true .

You need to back it off some it is to close. Give it one inch. Then when the stuffing tube is replaced you have to double up the end with several layers of larger tubing and solder or you can even red locktite them over each other. But unless that took some time to happen there might be as mentioned a reason the wollering seems excessive. You want a gap though of right at almost an inch as this will prevent the cable from getting a kink near the collet during a wipeout. When your close with the stuffing tube and engine gets abruptly jarred 1/2" even it can put a permanent Z bend in the cable between collet and stuffing tube and then it causes severe wollering and vibration.

If that is a bonzi or enforcer clutch with threaded collet it may be loose as well . The design it not to bright . I drilled a 1/4 hole in my bell in the mill to be able to lock the bell , then tighten the intergraded collet and the play went away . Check it for play only you can find out what is wrong . Check engine alignment also

That's the problem it's not a Bonzi or enforcer I've never had a problem with either , I have no idea what make this clutch is it has a lot of play in it , will probably replace it with a Bonzi unit

have you removed the clutch housing from the engine to have a decent look at the inner bearing that holds the clutch drum in place ? maybe all you need is a new bearing if its got the wobbles.

Will check that thanks...