Driveline Problems

[M.M.]

Okay guys, well I'm pretty disappointed right now. I've been working night and day for the past week to get my Miss Geico ready for this weekend. I got it all together and tested it tonight with a couple problems. The the main problem is that the stuffing tube and strut are getting hot to the touch just from bench testing the boat. Also everything is fine up until half throttle, but then I get a very bad vibration, I'm not sure if this could be part of the heat problem or not.I just greased/oiled the flex and prop shaft, so I have no clue why it's heating up. Can anyone tell me what's going on?? And would it be okay for me to run it this weekend?

[JimClark]

Test it in the water not on the bench

[M.M.]

That's what I was thinking I'll give it a shot tomorrow.

[martin]

You will get all sorts of vibrations & strange noises & it is not reccomended to run on the bench at high revs. You need to run it in the water so the motor & shaft has load on it & most of the noise wont be their unless you have something set up wrong or a problem with siomething.

[British Bulldog]

Just out of curiosity do you have any extra length on your flexi as when a flexi spins up it tightens and gets shorter,(im not sure by how much i can only imagine 2mm or so) which can lead to binding up the tube its supported in, i'm not sure if this a relevant thing being new to flexi shafts i can only ask if this may be the cause for the shaft and flexi to heat up regardless if its greased up or not? (something for me to learn about) I would have though at half throttle on the bench the tube shouldn't heat up till its hot & as when under loads it likely to still get hot if something is binding as nothing is cooling it, friction is the cause and grease should eliminate much of that, so prehap's this may be the cause?

If i'm way off base no worries, helps me learn.

With straight shafts i've never seen them get hot hot, warm yes but not hot.

Just my 2 cents but probably only worth 1

Regards BB

[M.M.]

Okay thanks for the help guys. I'll try it in the water today. As far as the flex shaft it is the stock shaft, which I have not modified. And yes I have left a gap between the strut and drive dog. I will also try re-greasing. And see if that helps