Stinger bushing failures.. Any Aquacraft guys?

[kwiktsi]

Ok, I know this isn't electric, but same principle. I have a Rio 51z and it keeps wiping out the stinger bushings. I have tried 3 different flexes and been through 4 stingers already. Aquacraft has been great with warranty parts but they are stumped as well. There are two short bushings- one at the prop and one at the transom. It only wears on the prop end and to the left side, which to me looks like it can't handle the prop load but they say they have not seen this before. The prop is balanced and sharpened. It is not razor sharp, but definitely sharper than out of the box and it balances perfectly level on my dubro tru-spin.

EDIT- I have made a full floating brass bushing for the stinger and rebalanced the prop. Shouldn't have any issues now.
Joe

[kfxguy]

What size flex? What size is the od of the bushing? See if you can put sealed ball bearings in. I stack 6 together and they hold up. Use sleeve retainer to hold them in. If the hole is too small see if you can find someone with a lathe to bore it out. With that large side load you may need 7 or 8 bearings.

[785boats]

It is not razor sharp, but definitely sharper than out of the box and it balances perfectly level on my dubro tru-spin.

kwiktsi.
When you say "balances perfectly level", do you mean that the blades always sit at the same level position. If so, then the prop is not balanced. You should be able to put the blades in any position & they stay there. If they fall back to that 'level' position, then anything under the center line of the shaft, is heavy. It will be the tongue on one blade, & the last third or so towards the tip of the other blade.
This may be causing the excessive wear on the bushes.

[kwiktsi]

What size flex? What size is the od of the bushing? See if you can put sealed ball bearings in. I stack 6 together and they hold up. Use sleeve retainer to hold them in. If the hole is too small see if you can find someone with a lathe to bore it out. With that large side load you may need 7 or 8 bearings.

Not possible to use bearings. It is a 1/4 prop shaft that steps up to about .305 where it comes off the flex and rides in the bushings. A bearing that size would be huge on the od. The bushings are only about 1/2-5/8" long, so not a lot of support there. I ended up drilling the stinger tube and pressing some brass tube into it then making a floating brass bushing that runs the full length. We'll see how that holds up.

kwiktsi.
When you say "balances perfectly level", do you mean that the blades always sit at the same level position. If so, then the prop is not balanced. You should be able to put the blades in any position & they stay there. If they fall back to that 'level' position, then anything under the center line of the shaft, is heavy. It will be the tongue on one blade, & the last third or so towards the tip of the other blade.
This may be causing the excessive wear on the bushes.

You know, I'll have to double check that. I was always told to spin it and it should land with even "blade" on each side (like an "X" profile). That makes sense though, learned something new. However, I don't think this was the issue- the bushing is only wearing on the left side, any time I have seen an out of balance prop cause bushing wear, it is always all around the bushing, not just on one side. Also, one of the other guys that runs his rio with us, his prop is right out of the box, no balancing, sharpening, etc. I put it on my balancer to check it and it has a very heavy blade on one side that instantly drops- far more out of balance than mine, which will roll slowly level if you give it a bump (not on it's own) and he has had no issues with his bushings. Open to thoughts on this though!

It's odd though- my boat is the fastest of the bunch but has been through about 5 mufflers (the stacks kept breaking loose, went tuned pipe now) and 4 stingers. Guess it's the tradeoff I'm making lol.


Edit- just put the prop on the balancer, if I spin it, it will land parallel more often than not. If I put it in any one position, it will hold there.

[kfxguy]

If you buy a new 1/4" shaft that's 1/4" the whole way, I'm sure it could be done. http://www.ebay.com/itm/10-Bearing-R...item5d2638aced

Come on man....use your noggin! I know you can do it. ^^^^^theres the bearings you need. If you just can't find anyone to do it, and it can be chucked in a lathe, send it to me I'll bore it for you. If those bearings won't work, let me know I'll dig up something else.

[kwiktsi]

Oh yeah, it can be done if I swap out the flex to a standard 1/4" flex- then I need to add a collet as well as remove the stock adaptor since it is slip in square drive. Way more work than I'd like to put into getting an RTR to work! Also, at this point, I don't think full bearings are needed- it's a stock Zen 26 with a pipe on it, I don't think the RPM's are high enough to justify it. These don't turn the RPM's that our electrics do :). There are many reliable, 60+ mph boats at our spot with just brass bushings and zero issues. I doubt I'll have any more issues with the new bushing I made, but I'm just stumped as to why my stock ones won't hold up when others are that are far more neglected and abused .

As for the lathe- If I do change anything and need it bored, I'll have to keep you in mind :). I have mine here but crashed it last week cutting something really small and stripped the spindle gears. Don't realize how much I use it until it doesn't work lol.

[kwiktsi]

Just checked out those bearings- that would actually be do-able if I did want to swap the shaft out for a standard 1/4 flex with collet. I'll see how the brass bushing holds up and at least I know that this is always an option.

[dasboata]

Ok, I know this isn't electric, but same principle. I have a Rio 51z and it keeps wiping out the stinger bushings. I have tried 3 different flexes and been through 4 stingers already. Aquacraft has been great with warranty parts but they are stumped as well. There are two short bushings- one at the prop and one at the transom. It only wears on the prop end and to the left side, which to me looks like it can't handle the prop load but they say they have not seen this before. The prop is balanced and sharpened. It is not razor sharp, but definitely sharper than out of the box and it balances perfectly level on my dubro tru-spin.

If my lathe wasn't broken at the moment, I'd just chuck the stinger in there, drill it out and make a full length brass floating bushing for it. The bushings aren't very long, so I think they are too small for the boat anyway, but a couple of friends have Rio's as well and I'm the only one with the problem. Heck, one of them is running the prop out of the box and rarely greases things. Mine comes apart after every outing (usually about 1/2 tank) for cleaning and grease. I added a grease fitting to the new stinger so we'll see how it does with grease being pumped into it between runs. Any thoughts? Thanks.
Joe

Perfectly level is not balanced ! add another bushing or 2 in the strut

[kwiktsi]

Perfectly level is not balanced ! add another bushing or 2 in the strut

Yup, learned something new today :). I had been misinformed years ago and just never knew any different. However, it will stop level more often than not if spun but if I put it in any position and let go, it stays there, so it's got to be fairly close at least, no? Even if it is out, would an out of balance prop cause it to wear on one side only like that though? Any failures I've seen in the past from an out of balance prop, the whole thing has been wallowed out. Thanks.

[dasboata]

Don't know what kind of bushings they use I use lead Teflon, the brass sleeve will work cut some grease holes in it , pics of the drive line shaft and strut would help

[kwiktsi]

Don't know what kind of bushings they use I use lead Teflon, the brass sleeve will work cut some grease holes in it , pics of the drive line shaft and strut would help

I'll take some pics when I take it apart to clean it again. The stinger is about 3" long and it is bushed the entire length with the brass now. I did drill grease holes in it as well and chamfered them on the outside. I also went ahead and re-balanced the prop, now it stops random places when you spin it and definitely holds wherever you put it. I don't foresee any further problems, I am just stumped as to what was causing it to begin with. Maybe a combo of the prop not being balanced properly coupled with barely adequate bushings? They are literally just a bit over 1/2" long and there is one on each end of the stinger, so they won't handle much load at all. They wouldn't even last a full tank typically.

[kwiktsi]

Well, with the prop rebalanced and my floating brass bushing, I ran the snot out of the boat today with no sign of wear at all. Between this and the tuned pipe (instead of the stock pos canister), today was the most I have used the boat without failure. Ran great! My Daytona also ran it's first laps with other boats today and while I had to slow down a bit in the turns, it destroyed them on the straights and handled the chop much better than I had expected. Overall, a very good day with the boats and no breakage :).