Cracked threads in center hub

[Rauno Vekkila]

Hi!

I had a project motor under strip down or perhaps even rebuilding process. Among many other things I found this. Is this common broblem or is someone just torqued bolts too hard?

 

[MaxMidnight]

Not something I've ever seen reported before so no, not common.

Assuming the height of the posts can be maintained then it may be worthwhile trying to helicoil. I'd use a pillar drill to ensure that the holes stay perpendicular to the face of the basket.

MM helpful hint #5: Don't try to tighten bolts with a hammer.

 

[Rauno Vekkila]

Thanks. I thought that Helicoil option also. Perhaps cut some material down with lathe and set shimms. First I’ll ask for a professional opinion on the crank is it worth saving.

 

[maleko89]

Hi!

I had a project motor under strip down or perhaps even rebuilding process. Among many other things I found this. Is this common broblem or is someone just torqued bolts too hard?

I'm wondering if someone used a home made tool or screwdriver to hold the clutch boss on those posts in order to remove the nut and inner clutch components from the shaft?

 

[02GF74]

Wow - that's horrific.

My guess is someone fitted a plate with holes larger than the bolts and tightened the bolts so the alloy pushed through the holes then used a pry bar/chisel to hit the plate from behind.

Anyway, exactly how this was done doesn't matter but how to fix the mess.

From your name it sounds like you may be in Finland so I don't expect availability of spares to be anywhere as good as in USA. You may be able to find a spare in Europe.

I would look to getting a replacement.

If the threads are stripped then helicoil may be fitted but there doesn't look to be much metal left once the posts have been drilled and tapped for the helicoil. Note rule of thumb is helicoil (or any thread) needs to be be 1.5x bolt diameter in length - it may be possible to drill the holes deeper and tap the holes and use longer bolts (I'm not familiar with this component)

Also I would expect it is important for the plate to sit parallel on the basket so the posts need to be the same length - you need to measure this and if not, have them machined and use a spacer so the length is the same.

Depending on what needs to be done to fix this, make sure the part isn't going to fail as that may trash the engine case resulting in even larger bills!!!

My gut feeling is it will be cheaper and safer to replace.

BTW this part is spinning at high RPM so any repair should be the same for all posts (and bolts the same length) so the assembly is balanced.

Sean (THE Vmax guru) may advise.

 

[sdt354]

I'm wondering if someone used a home made tool or screwdriver to hold the clutch boss on those posts in order to remove the nut and inner clutch components from the shaft?

My first thought too Mark. Only an air impact, or proper holding tool, easy to make from old disk, should be used.

 

[Parminio]

I would look to getting a replacement.

If the threads are stripped then helicoil may be fitted but there doesn't look to be much metal left once the posts have been drilled and tapped for the helicoil.

That.

I'd definitely replace it. It may be a long shot, but you could see if Sean Morley @one2dmax has one (he works on tons of Vmax's and may have an extra) and also even @CaptainKyle as he has quite a few Vmax's and may have one as well or know where to get one.

 

[CaptainKyle]

That.

I'd definitely replace it. It may be a long shot, but you could see if Sean Morley @one2dmax has one (he works on tons of Vmax's and may have an extra) and also even @CaptainKyle as he has quite a few Vmax's and may have one as well or know where to get one.

I have quite a few of them

 

[Rauno Vekkila]

Wow - that's horrific.

My guess is someone fitted a plate with holes larger than the bolts and tightened the bolts so the alloy pushed through the holes then used a pry bar/chisel to hit the plate from behind.

Anyway, exactly how this was done doesn't matter but how to fix the mess.

From your name it sounds like you may be in Finland so I don't expect availability of spares to be anywhere as good as in USA. You may be able to find a spare in Europe.

I would look to getting a replacement.

If the threads are stripped then helicoil may be fitted but there doesn't look to be much metal left once the posts have been drilled and tapped for the helicoil. Note rule of thumb is helicoil (or any thread) needs to be be 1.5x bolt diameter in length - it may be possible to drill the holes deeper and tap the holes and use longer bolts (I'm not familiar with this component)

Also I would expect it is important for the plate to sit parallel on the basket so the posts need to be the same length - you need to measure this and if not, have them machined and use a spacer so the length is the same.

Depending on what needs to be done to fix this, make sure the part isn't going to fail as that may trash the engine case resulting in even larger bills!!!

My gut feeling is it will be cheaper and safer to replace.

BTW this part is spinning at high RPM so any repair should be the same for all posts (and bolts the same length) so the assembly is balanced.

Sean (THE Vmax guru) may advise.

Oh yes, I’m from Finland. Most likely I will find used spares from here but this is definitely not the only issue..new cases came with the project engine.

Thank God my bikes main engine is in working order so I don’t have to hurry with this beaten bas****

 

[Fire-medic]

Just remember to JB Weld it sufficiently, treat it like a jigsaw puzzle, and when it's hardened, sand-down the case exterior after you've applied the smoothing JB Weld coat to the outside. That should do it.

Or not.

I'd get a new clutch hub, or a used one from CaptainKyle. [email protected]

I have a Motion Pro clutch hub holding tool that is the right tool for the job. Motion Pro Clutch Hub Holder - RevZilla

 

[Vinmax]

Oh yes, I’m from Finland. Most likely I will find used spares from here but this is definitely not the only issue..new cases came with the project engine.

Thank God my bikes main engine is in working order so I don’t have to hurry with this beaten bas****

There's a perfectly good explanation of how that engine got to looking like that;

 

[DreamV4]

Check ebay prices.

 

[norcalAF]

Just remember to JB Weld it sufficiently, treat it like a jigsaw puzzle, and when it's hardened, sand-down the case exterior after you've applied the smoothing JB Weld coat to the outside. That should do it.

Or not.

I'd get a new clutch hub, or a used one from CaptainKyle. [email protected]

I have a Motion Pro clutch hub holding tool that is the right tool for the job. Motion Pro Clutch Hub Holder - RevZilla

On my first bike, a Suzuki intruder 1400 I bought well used, I noticed a small oil leak that seemed to be originating from the center of one of the engine covers. Imagine my surprise when my finger poked straight through the cover with minimal pressure! Someone had used jb weld to plug a quarter sized hole. I had ridden the bike several hundred miles with it like that. I ended up taking the cover to a local guy that welded aluminum and had it properly fixed for $20.

 

[Fire-medic]

Making a heliarc repair is definitely the way to go. I hope people recognize that my comment about using J-B Weld to try and piece a case back together again was a tongue-in-cheek comment about some of the dodgy fixes people attempt to make, and in no way should be anything that someone should attempt as a fix on a busted case.

Being famous that people find on their bikes as they're attempting to funnel them into safe operational condition that can be a scary Prospect, as you found out. It makes you wonder about what else might be done or not done or safely done. Any used bike should get a thorough going over to check for operability. Perhaps we should have a new Thread about all the stupid things people find with their used bikes. Did you happen to take any pictures of that JB welded side case cover?