Grease Problem? ( noob alert)

[the5]

Well i got my MG running. I did a dry bench test for the first power up. First it was nice smooth sound then stated to make a shuttering sound them bck to normal. This happened back and forth. All this grease had came out from the flex shaft. Is this normal? Also the flex pipe was hot. Also hw do i grease a flex shaft and does amin have the grase?

[jac4412]

No that is definitely too much... When I run my MG I don't notice any grease coming out at all... What type of grease are you using? What flex do you have? If your flex shaft is fluttering like that either you've got the wrong flex in there or its been damaged in some way... or there's a problem at the coupler. Either way you shouldn't be getting enough friction to cause heat and a leak.. somethings wrong.

[the5]

this was all done on the bench and i may have pushed it too hard. I bought the boat used. It had a neu setup in it. I dont no the grease but could you recomend some? Also how should you attach a flex shaft to a motor?

[Rumdog]

Is your prop balanced? Also, do not run WOT on the bench.

[the5]

Ohh i ran full throtel is that the problem?

[sundog]

this was all done on the bench and i may have pushed it too hard. I bought the boat used. It had a neu setup in it. I dont no the grease but could you recomend some? Also how should you attach a flex shaft to a motor?

Like Rum said, don't run WOT on the bench for more than a spurt. You probably had too much grease on the shaft. Too much grease will ADD FRICTION and slow things down. Most any grease will do - apply a light coating on the flex shaft. A stuffing tube immersed in water won't build up heat like on the bench. If the flex is flopping around in the tube, consider using a teflon liner as well. Attach the flex line to the motor with a collet for best results.

[domp444]

Could the flex shaft be flopping around because there is no force/resistance on it? It's just pushing air, when it's in the water it should have more resistance, and I think this would stop the flopping. Does that sound right?

[forescott]

I'm assuming that all the geico's have had the flex shafts replaced that were the wrong rotation! Make sure the flex shaft is wound in the right direction and spinning the right way.

[forescott]

I've learned that not just any grease will do. The lighter greases will wash away really fast when heated up by the flex cable. I stick with the grimracer grease. It seems like it would be too thick, but a thick grease will thin out when it gets hot and you need it to stay in the stuffing tube and not work its way out too quickly.

[sundog]

Forescott I stopped using Grimracer grease a while back as it is too viscous. Try to turn the flex shaft with your fingers after applying Grimracer and you'll see what I mean. I don't believe grease heats up enough to lower viscosity significantly when the boat is in the water. But what grease to use is a much debated subject. Whatever you feel good about using will work. You may have to re-apply some more often. If you stop using Grimracer grease your boat will go faster. Of course I'm talking about FE here, not petrol boats where the torque can be much higher. In that case a thicker grease may not affect things as much.

[Rumdog]

Lol. No wonder my boats have been such dogs. That damned grimacer grease. Rofl.

[sundog]

Lol. No wonder my boats have been such dogs. That damned grimacer grease. Rofl.

Rumdog I suspected my statement might be cause for heated debate, but I jumped right in with both feet anyways! Yeeeeaaahh!.

[forescott]

I used to use thinner lithium grease because, like you said, the prop seemed hard to spin by hand with thicker grease. But I found I was getting a lot of water up the shaft. After one short run with thin grease I would pull the flex and find the cable dripping with water and no signs of any grease. If you think about the tight tolerances between the flex shaft and stuffing tube and that shaft spinning at 25-30k rpm. I believe that thick grease is gonna get hot enough to thin out a little. Would you grab hold of a cable if it were spinning at that speed? Yeeouch!! Back at ya sundog!

[sundog]

If you think about the tight tolerances between the flex shaft and stuffing tube and that shaft spinning at 25-30k rpm. I believe that thick grease is gonna get hot enough to thin out a little. Would you grab hold of a cable if it were spinning at that speed? Yeeouch!! Back at ya sundog!

I guess we'll get lots of opinions on this, but tight tolerances and thick grease don't get along well in my opinion. How hot does Grimracer grease need to get to become viscous? And ask yourself, does it get that hot in most boats? I run mostly smaller boats where this can make a big difference, but I still think it applies to larger boats as well.

Gotta take care of business, Y'all discuss this amongst yourselves. I'll check back this evening!

[AlanN]

The alignment of the stuffing tube to the strut is not straight. This can cause excessive friction in the stuffing tube. And if the bend in the stuffing tube is not just right (alot of trial and error here) it will also build up heat. I have chased down alot of heat causing bends and alignments in my drives. There can be multiple reasons for a hot tube. The stub shaft may not be centered on the flex cable. Keep working on the drive line until you can keep the stuffing tube from getting hot.