question on tube dia.

[Gary]

I know this was covered in another thread but my question was not really clarified.Im running a .187 cable in a 1/4 brass stuffing tube and it seems alittle loud like mabe its moving around to much in the tube. Will a 7/32 be better? I heard they were to tight and generate to much heat on the .187 cable but it does fit nice and snug with no cable side movement. I always ran a nylon liner and back to back testing has shown no speed increase without it so mabe a smaller dia. tube????????? Any thoughts.

[forescott]

I hope it works well because the 7/32 tube is what I have in my 41-inch mono set up. I havent run it yet, but I think it will work great. I may just need a good recommendation for what type of lube to use!

[forescott]

1/4 inch just seemed waaay too sloppy to me!

[steveo]

both are ok for what i have read i just switched to 1/4 from 7/32 and alittle sloppy but nothing that bad, i think i can live with alittle more noise with a a less resistive drive line
i have not run the boat yet i moved the motor foward and just went a head and changed it up, there is a quite a difference between the two being smooth

[steveo]

i was just thinking if its to noisy maybe you could slip a piece of 7/32 through the 1/4 up to the bend that might help i might experiment with that

[forescott]

Why did you switch?

[BakedMopar]

I use 1/4" with my .187" cable. Not an issue. I've had issues with the 7/32" though on one boat as it had too much bend. Think of it this way, that's the same diameter you use for a 3/16" stub bushing.

[Gary]

Well noise is not important to me but i just thought it sounded a little loud like it was winding? up a tiny amount and causing a vibration within the tube which i know will rob power and cause a possible problem. Forescott i switched only to find a tad more speed. Boat is stuck around 84-85 and i just like the chase for more!!

[Gary]

Well answerd my own question today. Tried the 7/32 tube and it was smoking hot. Cooked all the oil out real fast so i guess it is to small a diameter. Now i know !! Thanks anyway guys.

[forescott]

Oh crap! Bad for me! What rpm do you think you're spinning?? My setup should be around 30,000 unloaded rpm. Maybe my setup will run cooler?? I'm not looking for 85+ mph.

[Gary]

Im around 38,000 at top speed. It was pretty hot and when I took the hatch off smoke came out. Not good!!!!Driveshft was also discolored.

[AlanN]

The tighter fitting tube needs constant lubrication. An oiler works but you must still be carefull. 1/4" and 3/16" cable doesn't really like 20,000+ rpms. I have been through this many times with larger hulls. I often have to re-do the stuffing tube. My best 3/16" stuffing tube was an S bend out of 1/4" and filled with Mercury cable grease for my 1/8 scale. Didn't have to regrease every run. Not sure if it was the s bend or the strut that kept the grease in. But I did put alot in. Then held my finger over the opening when I pushed the cable in. Messy but effective.

[forescott]

Anyone out there having success with 7/32 tube & 3/16 flex??

[BakedMopar]

This morning I put four two minute runs on my hydro spinning mid 30k unloaded (.250" /.187"). Still had a good amount of grease left on it when I took it out at home. I agree that it ain't quiet but it works and you'll never hear it once in the water.

[marko500]

I run a 3/16 cable in a 7/32 tube in a cat and no problems yet, but I regrease it after every other run. I did sand down the cable very slightly before I installed it and the tube has a VERY slight bend in it. I also run a 3/16 cable in a 1/4 tube on a hydro and have no had problems after about 8 runs. The cable in the hydro definitly feels easier to turn by hand. I will probably end up switching the cat over to the larger tube eventually.

Mark