noise in Mystic 29

[Boats a go go]

I am fairley new to boating . I have a Proboat Mystic 29 and have probably run it 25 times. I have greased the drive about 5 times and now i am getting a noise at high speed that sounds like the flex shaft is scraping on the tube ?? Any suggestions on a fix .
Thanks
Boats a Go Go

[roadrashracing]

I grease my flex after each day of running, how does the liner look?

[Darin Jordan]

Check a couple of things...

1) Remove the motor, then slide the flex shaft all the way in until the drive-dog seats against the strut. Make sure that the front of the propeller shaft it's not contacting the teflon.

2) Make sure that the teflon isn't rotating inside the brass. This is really NOT likely to be an issue, since the teflon in these is pretty hard stuff and fits pretty tightly in the tube, but worth looking at.

3) Make sure that the motor is mounted such that it's not forcing the flex up against one side of the stuffing tube/teflon.

4) Look at the propeller shaft and make sure it's polished smooth where it contacts the strut bushing. If it looks burned or like it's seizing, then your strut bushing may need attention. I always run my propeller shafts through my buffer and polish them to a mirror finish. Seems to help. The bushings in these struts are hard, and not very forgiving. Once they start to go, they can seize on the shaft. Haven't seen this much, but it's something to look for.

5) Make sure that the wood around the area where the motor is mounted is firmly glued down. The large flat motor-mount area isn't glued in all the way around, and I've seen them get loose. I epoxy coat all of the wood and seams in this area, and a lot of the noise from the boat running goes away. The wood here resonates the any vibrations and vibrates against itself in the joints. Epoxy it all and that will help.

6) Don't use TOO thick of grease... The Pro Boat or Grim Grease is great stuff. I would also look at using some 90W, or similar (I use Mercury lower unit lube) on the propeller shaft itself. It tends to get into the bushing and stay there better. If you use too thick of grease on the shaft itself, it'll cause drag, especially when it's cold out. It's in the bushing itself where it's the most important to grease/lube things.

Hope something here helps!

[Boat guy]

Just reading since I have a similar issue What do I do if the Teflon is spinning or vibrating inside the tube, I have same issue on miss Geico and I have pulled the entire liner out to check for a crack and it's fine. The vibration is coming from the strut but the bushings look ok and no damage to wires in shaft. I will check all pars to see if loose but I epoxied all of it after the first crash. I noticed the trays etc were all loose and needed epoxy on the back transom as well. Prop is balanced and even w the prop off it makes a bad vibration and you can feel the strut get hot. Just with a little running. 1-3 seconds at most. When full of grease it goes away for a bit. Any help. Thx

[Boats a go go]

If I didn't know better I would think you had my boat. I have tried everything you have to no avail . I am now waiting for some Proboat grease to see if that changes anything. I have been using axle grease that I use in my boat trailer ( this may too thick ? ). The only thing you have done that I haven't is remove the teflon liner. Mine dosen't seem to want to come out ?? My boat is out for repairs ( slight racing accident) but hope to get it back running soon so I can continue my quest for a smooth running boat.

[Boat guy]

Right I have pro boat grease it goes away for a while but comes back. Do you have lead Teflon bushings in strut. That was my next move. Also new shaft looks bent, also had bad accident w mine.

[Boat guy]

I am told replace the brass with lead Teflon bushing in strut may fix it. Also told new shaft will fix it but it looks like you tried that as well.
We are in the same boat, all jokes aside!!

[Boat guy]

Has anyone tried to make a bushing for the strut out of something else?

[Darin Jordan]

Guys... I've had the same issues... I tried some oil on the stub shaft instead of grease. Seemed to work pretty well.

[Boats a go go]

Hi guys . Thanks for all the info. My boat isn't back together yet but before the accident I tried some of Darin's suggestions . The motor was slightly out of alignment . I fixed that . I checked to make sure there were no loose parts . I can't figure out how to get the teflon tube out as it isn't loose at all. With all that said it was a little better but still somewhat noisey. I just got the proboat grease so that is my next change and will also try Darin's heavy oil on the bearing. I have never tried to replace or make a new bearing . I will see how these changes stand up before I get into that .
Thanks guys for all the help

[nokiaprinter]

Darin, may i ask what kind of oil did you use?

[Darin Jordan]

Darin, may i ask what kind of oil did you use?

It's a mixture of STP and Marvel Mystery Oil...