Strut bushing ?

[tiqueman]

I rebuilt a boat a few months back and installed a Miss Vegas strut. I crafted my own strut bushing using 2 pieces of brass.. cut the slots in it etc etc. A few runs w/ that set up and a minute or so into a run it would begin to develop a whining sound. I actually thought at first I had a bearing going bad in the motor, but after a bench test with the motor out I found that it was fine and determined the annoying sound was from the strut. I thought maybe it was something I did wrong in the home built bushing, so I spent the insane amount of money on an AC bushing and had the same results. I changed out the brass bushing for a lead teflon and have had no problems since. My AC SV runs the factory strut bushing and is quiet as can be.

So I just finished a twin build using HOTR 4mm stingers. I drilled about 3/8 into the end using a 1/4" bit, and again, made my own bushings to allow 3/16 shafts and omit the 4mm stuff. First run was quiet as can be. But was only 45 seconds long before losing a prop. 2nd run, the whine developed and 3rd run its even worse. Im using Grim grease and tried adding oil w/ no results. Is this just a common problem w/ the brass bushings. Im thinking of going the led teflon route w/ these as well. But not having a drill press, Im hesitant to try and drill all the way through the stinger. If I drill it just a bit more, another 1/8 or so to give it approx 1/2" depth, is that spaced enough for the use of two lead teflon bushings in each stinger?

Thoughts?

[Jeff Wohlt]

Put a couple of spots of solder around it on each end and file it down so it fits tight in the strut.

[m4a1usr]

I rebuilt a boat a few months back and installed a Miss Vegas strut. I crafted my own strut bushing using 2 pieces of brass.. cut the slots in it etc etc. A few runs w/ that set up and a minute or so into a run it would begin to develop a whining sound. I actually thought at first I had a bearing going bad in the motor, but after a bench test with the motor out I found that it was fine and determined the annoying sound was from the strut. I thought maybe it was something I did wrong in the home built bushing, so I spent the insane amount of money on an AC bushing and had the same results. I changed out the brass bushing for a lead teflon and have had no problems since. My AC SV runs the factory strut bushing and is quiet as can be.

So I just finished a twin build using HOTR 4mm stingers. I drilled about 3/8 into the end using a 1/4" bit, and again, made my own bushings to allow 3/16 shafts and omit the 4mm stuff. First run was quiet as can be. But was only 45 seconds long before losing a prop. 2nd run, the whine developed and 3rd run its even worse. Im using Grim grease and tried adding oil w/ no results. Is this just a common problem w/ the brass bushings. Im thinking of going the led teflon route w/ these as well. But not having a drill press, Im hesitant to try and drill all the way through the stinger. If I drill it just a bit more, another 1/8 or so to give it approx 1/2" depth, is that spaced enough for the use of two lead teflon bushings in each stinger?

Thoughts?

How much of the flex hard shaft is being supported? The more the better. Also, you are drilling a relief/ clearence without a drill press? You got better eyes then me for sure. Its tough to drill straight with a hand drill. Especially when going a distance like you need. Dont hose up some good hardware if you dont have the right tools. With stingers I like at least 2" of stubb support but if you support each end with a narrow bushing it can actually be better for reducing friction. Lead teflon bushings are amongst the best. Time proven and with excellent lubricity characterics they are old school yet a great choice. But they wear fast if the drive is prone to vibration or out of tolerance dimensions.

A little more detail might help in your setup.

John

[tiqueman]

Put a couple of spots of solder around it on each end and file it down so it fits tight in the strut.

They are tight in the stinger already and cannot spin if thats what your getting at.

How much of the flex hard shaft is being supported? The more the better. Also, you are drilling a relief/ clearence without a drill press? You got better eyes then me for sure. Its tough to drill straight with a hand drill. Especially when going a distance like you need. Dont hose up some good hardware if you dont have the right tools. With stingers I like at least 2" of stubb support but if you support each end with a narrow bushing it can actually be better for reducing friction. Lead teflon bushings are amongst the best. Time proven and with excellent lubricity characterics they are old school yet a great choice. But they wear fast if the drive is prone to vibration or out of tolerance dimensions.

A little more detail might help in your setup.

John

All of the hard shaft is being supported. Im not sure what your saying about a relief clearance. But as mentioned in my original post, the stinger (again originally set up for 4mm shafts, with the 4mm bushings removed) accepts a 7/32 brass tube with a good fit. I then drilled the tail end of the stingers about 3/8 deep using a 1/4" bit. Then made the bushing like a standard bushing using 7/32 brass with a small piece, in my case about 3/8long of 1/4" brass tube over one end.
What other detail do you need? Im not sure what else I can say about it?

[ozzie-crawl]

is the bushing straight inside the alloy strut ?
to bad you cant drill stingers out to 1/4 then add 1/4 brass tube,then you would have brass to brass contact.

[Jeff Wohlt]

Yep I thought it was spinning inside the stinger. Check your shaft good and see if it is making contact somewhere. It would be real shiney.

[tiqueman]

is the bushing straight inside the alloy strut ?
to bad you cant drill stingers out to 1/4 then add 1/4 brass tube,then you would have brass to brass contact.

Yep I thought it was spinning inside the stinger. Check your shaft good and see if it is making contact somewhere. It would be real shiney.

I looked for wear spots as well. Nothing catches my eye. Using a caliper as deep as it can go, which seems to be about 1/16" from being all the way to the end of the drilled 1/4" area, its tru and the bushings should not be going in crooked.

Before I changed out the bushing in my single drive, it ran thru 1/4" brass and I had the same issues. Also it spins extremely free when all is installed.. both drives.

[Jeff Wohlt]

Probably should not even worry about it then. Might be a bearing in the motor?

[tiqueman]

Probably should not even worry about it then. Might be a bearing in the motor?

Just as my single drive, w/ motors disconnected from the shaft they are quiet as can be. Plus these motor in the twins have less than 8 minutes run time on them.

[ozzie-crawl]

is the noise there in the water or only when on the bench

[Rumdog]

Are your bushings a slip or press fit? If they are slip, do the rotate freely within the strut?

[tiqueman]

is the noise there in the water or only when on the bench

Both

Are your bushings a slip or press fit? If they are slip, do the rotate freely within the strut?

Press

[ozzie-crawl]

on the bench they all ways make a terrible noise, how bad is it when in the water?

[tiqueman]

on the bench they all ways make a terrible noise, how bad is it when in the water?

Its not horrible, but you can hear it. Enough that it drives me nuts. An observer would probably not recognize the noise and think its normal. But like I said, it bothers me and IMO means something isnt quite right. I will be up near the LHS mid week. I will probably pick up a few sets of lead tef bushings and be done w/ it. This mornings run, she was quiet w/ fresh grease and oil on the first pass, then started shortly ther after.

Im leaning towards a friction noise, seeing how that once fresh grease is slung around it then starts... I more just wanted to know if anyone else has the same issue and it seems at least 1 does. Also the amount of support needed in using the teflon bushings. Can I only carry half the stub shaft, or do I have to get one up near the front?

The one I installed in my single drive cat I havent even had to think about after swaping to them them. They are quiet as can be.

[Jeff Wohlt]

As long as you have one midway on the shaft and at the end you are fine. Some of the older Fuller struts on had one at the end of teflon such as the Octura style. I always crammed another down it pushing the other one midway on the shaft.

Some German struts I modified for bearings have a brass ring at one end and one at the front...I find these to be the smoothest turning.

Does it sound like this one? It has bearings.

http://www.youtube.com/watch?v=RM8keupHaHw