Stuffing tube rattle.

[Ripper]

Maybe someone can help. I have a MG with a 4082-2200 which I've run a couple of times and runs great around 60 mph but even before the new motor went in, when I test it on the bench with the stuffing tube fully greased at slow speed it sounds smooth as silk but when I punch the throttle it sounds like a bag of marbles in the tube. The boat has always run great stock or modified and I've never felt the stuffing tube get warm after a run. I'm running the original teflon bushing and I've checked the strut bushing for wear and it seems fine. The flex shaft is a replacement OSE. Am I being paranoid or is there something going on here that I'm missing?
I'd appreciate any feedback and thanks in advance.

[detox]

Listen for that sound while boat is running in the water. Usually that bag of marbles sound will go away when prop is under load. If not try adding MORE CABLE LUBE.

Try not reving motor while boat is out of water.

[martin]

Yep you will get that sound running out of the water with on load, you shouldnt run out of the water with no load on ecspecially at high rpm.

[Ripper]

Thanks Detox, that's kind of what I thought but wasn't sure. I've never heard it while it's running under load. I don't run it for more than a second or two on the bench just to see if things are working. I will load up with as much grease as I can in the tube. Any opinion on pulling out the liner and just running without it I hear some yay and some nay. Maybe it's just a personal choice.

[Ripper]

Thanks Martin, You and Detox are in agreement and that's enough for me. I'll keep my finger off the trigger when it's dry and always make sure it's loaded with grease which I've been pretty good at keeping up on especially running the 4082-2200Kv on 5s with an M645 it gets pretty scary around 60. I just know with that kind of power when I blow something up it's gonna blow big time.

[detox]

Your strut bushing acts as a squeegy, removing most of the grease as cable is slid into stuffing tube. Remove your strut bushing from strut before greasing then slide bushing over greased prop shaft. Now grease your cable then insert bushing/cable into stuffing tube/ strut.

Lately I have been using transmission fluid mixed with Grimracer grease. First I grease the cable then I dip cable into transmission fluid.

I like the liner, but lots of experienced racers do not use liner (.187" cable with .250" brass tube).

[TheShaughnessy]

If you get the Proboat grease.gun you can just pump the stuffing tube full of grease. No need to remove bushings. If you want to take out the liner it would be best to go to .187 flex instead of the stock .150. Or keep your cable and go to 7/32 k &s tube, but that would be a pita. Just my opinion, but at that rpm bushings are going to wear faster and maybe.that little bit of slop is making all that noise.

As for bearings. Yeah they are cool but, the ones I run are 10 bucks a pop they don't last forever and it seems to get worse if you have any strut angle. Maybe having two in the rear of the strut would help. Then again I don't want 30 bucks in bearings in my strut. I will stick with bushings in the future, but that is just me.

[martin]

Most racers that i know use custom struts with 2 bearings at the rear of the strut & 1 sometimes 2 at the front. 1 bearing at the rear is next to usless as it simply wont take the load & ends up wearing faster. The ball bearings i use are $1 each so i can replace as & when.

[TheShaughnessy]

where are you getting these bearings at? I'm not sure i could even fit two of them in the rear. I'm going to try though because i agree, 1 in the rear is next to useless as it seems to be loaded more then the front. I pulled the wire drive and the inside of the rear bearing came with it.

[martin]

Im in the UK & get them there, the ones i use are for rc car axles + anything else they use them on in cars. I custom make most of my struts so i make them to take whatever i need re number of bearings or different size bearings & shafts.

[mtbenjamin77]

Thanks Detox, that's kind of what I thought but wasn't sure. I've never heard it while it's running under load. I don't run it for more than a second or two on the bench just to see if things are working. I will load up with as much grease as I can in the tube. Any opinion on pulling out the liner and just running without it I hear some yay and some nay. Maybe it's just a personal choice.

If you run without the teflon get rid of the stock stuffing tube It flimsy junk replaced it with a 1/4" tube and run a 3/16 flex. your drive will be smooth as silk loaded or not. i think the rattle is that thin stuffing tube vibrating