K4.6 Starter Shaft HPI 15234

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My starter shaft for my K4.6 engine is badly worn and causing the one way bearing to slip. I've replaced the one way bearing but it still slips. The Starter shaft seems to be rarer than cryptonite, I've searched google for hours and the part is out of stock everywhere. has anyone got any ideas of an alternative or know anywhere that may have the part? I'm based in the UK.
Bought the truck second hand as a little project for my son, but so far we haven't even been able to get it running.
Cheers
 

ELWOOD

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My starter shaft for my K4.6 engine is badly worn and causing the one way bearing to slip. I've replaced the one way bearing but it still slips. The Starter shaft seems to be rarer than cryptonite, I've searched google for hours and the part is out of stock everywhere. has anyone got any ideas of an alternative or know anywhere that may have the part? I'm based in the UK.
Bought the truck second hand as a little project for my son, but so far we haven't even been able to get it running.
Cheers


Do you have the Ball end with the cross pin (Roto start ) or the 1/4" Hex ball (Nitro start) at the end of the starting shaft ?
 

olds97_lss

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Do you have the Ball end with the cross pin (Roto start ) or the 1/4" Hex ball (Nitro start) at the end of the starting shaft ?
This 87617 vs 87116




I just gave mine away recently, well for shipping costs. The old engine, rotostart and shaft. I think it used the chrome one. It had a pin in the end.

If it were me, I'd huck it and get a pull-start. Or, I'd cut a slot in the sides of the cup with a dremel and find a dog bone that would fit in it.

Maybe the losi one would work?
https://www.amainhobbies.com/losi-spinstart-starter-shaft-losb5104/p5974
 
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It's not the roto start shaft that I'm looking for, its the internal starter shaft that goes into the internal one way bearing inside the motor behind the roto start shaft. Its worn on the end where it sits in the one way bearing, and I can't get it to grip in the bearing.
 

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ELWOOD

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By the way are you starting engine with a drill ? as they can over torque your OWB and damage the shaft if you don't "clutch" the drill down like the NITRO start dose. Try sanding shaft with oil and say 2000 grit wet/dry sand paper. just do the area where OWB rides ,stay away from the area where the shaft is in the bronze/brass bushing in the back plate.

https://www.ebay.com/p/HPI-15234-Starting-Shaft-NITRO-Star-K4-6/672824465
 
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Here is one

By the way are you starting engine with a drill ? as they can over torque your OWB and damage the shaft if you don't "clutch" the drill down like the NITRO start dose. Try sanding shaft with oil and say 2000 grit wet/dry sand paper. just do the area where OWB rides ,stay away from the area where the shaft is in the bronze/brass bushing in the back plate.

https://www.ebay.com/p/HPI-15234-Starting-Shaft-NITRO-Star-K4-6/672824465
Yes i'm using a drill with a clutch, I thought it could be the drill over powering the one way, although I have the clutch set on the lowest setting and its not clicking off. I will have a go at sanding the shaft.

I am already in contact with the seller on that ebay listing but the postage to the UK from USA is ridiculous, it would be nearly as cheap to source another engine!
 

ELWOOD

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Most cordless drills have a DRILL setting and a SCREW setting ,the clutching only works on the SCREW setting. you may have already stressed your new OWB. Wow I didnt know shipping was that bad to UK I just know from UK to USA can take month or more with "Royal Air: and then its stuck in customs for another week or so, I guess you pay either way.
 
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I have had some results, I replaced the one way bearing again and it turned over a few times before slipping with the drill, I pulled it apart again and noticed that it wasn’t actually the bearing slipping, but the whole bearing slipping in the housing, so I refitted the bearing with some anaerobic retainer and tried again. No more slip, but the drill (18v Dewalt cordless) wouldn’t spin the engine quick enough for it to fire up.
So I tried my Sullivan starter from my helicopter and it fired straight into life! Managed to give it a blast up the road before the throttle servo saver kept jamming he throttle open as it’s slipping on the servo output shaft. So need to fabricate another throttle assembly. Oh and I’m waiting on some brake pads to come as there isn’t a lot left of them.

On a plus note, I think I’ve found a solution to the starter shaft, I’ve ordered a hobao one from a .28 hyper engine that looks identical and was in the UK so hopefully it will fit! Watch this space! I might finally get the old girl running at some point!
 
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