SH2: The Rebuild (Image Heavy) - Page 18 - SV650.org

muzikill · 31-10-11, 11:35 AM

If the main bearing had gone and with the amount of rotor damage there is you would think when you removed the rotor wheel the crankshaft movement would have been obvious.

squirrel_hunter · 31-10-11, 08:05 PM

Quote:

Originally Posted by muzikill

If the main bearing had gone and with the amount of rotor damage there is you would think when you removed the rotor wheel the crankshaft movement would have been obvious.

You would have thought it would be obvious... So checked tonight and yep, its oval. I can rock it up and down, I can also rock the conrods from side to side, but I can't get the pin out of the piston. I need heat.

yorkie_chris · 31-10-11, 08:56 PM

Side to side or angular motion is normal, up and down motion = knackered

squirrel_hunter · 01-11-11, 10:07 PM

Part 18; Two halves don't make a whole:

I have the answer...

I spent a couple of hours taking the motor apart this evening. After getting a little heat on the piston I got the pins out and could go about the rest of it. This time the clutch was intact and the rest of the engine came apart easier than before. There were a couple of screws that were an issue last time but this time the impact driver was not needed.

But before I give the answer out, and its a good one, a picture of my work bench. Its custom made, by me and my Dad. Its unfortunately about 6 inches too tall so I had to stand on a toolbox to get over the engine to split the cases. So here is what an engine looks like, and there are more bits in a box on the floor:

And now the answer.

Note, this is a picture not of two cranks:

And the money shot:

Awesome, a split crank. Quick inspection don't show a great deal of damage to the cases but I'd want to replace a couple of bits for sure. Need to clean it up properly and take a fresh look at it.

So what to do... I have an Arc welder and Stretchie has a Mig welder, I think we can fix it. No?

01-11-11, 10:18 PM

ffs-unreal-would you not be quicker just getting a replacement engine

yorkie_chris · 01-11-11, 10:53 PM

Yeah, stick weld... use cast iron rods, the more carbon the harder it is so that must be better, right? Hog back into shape with angle grinder then file around, finish off with 60 grit sandpaper and spit.

On serious note, this does definitely make me wonder about the wisdom of grinding cranks, as they don't normally snap there. I definitely won't be getting mine ground on big end to build a tuned motor with. Whether that be heat from the initial damage, heat from grinding, stress concentration changes from grinding whether internal or external...

OTOH, split the big ends and post pics, let's have a look. Maybe a rapid seizure could cause the snap. Still not really ideal...

muzikill · 02-11-11, 08:46 AM

Thoughts on the chain of events that led to the damage?

Bearings goosed due to little lube, crank dropped on rotor side causing opposing rotor magnets to hit each other causing further stress on the crank leading to full rotor side crank siezure causing stress in the middle of the crank shaft as the crank siezure wasnt even.

It still amazes me how much power comes from these little engines.

Sent from my GT-I9100 using Tapatalk

maviczap · 02-11-11, 09:06 AM

It'll make a nice paper weight

_Stretchie_ · 02-11-11, 09:30 AM

Quote:

Originally Posted by squirrel_hunter

The rest of the engine came apart easier than before. There were a couple of screws that were an issue last time but this time the impact driver was not needed.

That's cos we put this one together ; )

Quote:

Originally Posted by squirrel_hunter

So what to do... I have an Arc welder and Stretchie has a Mig welder, I think we can fix it. No?

I can sense a future thread to do with Squirrel lay in hospital

Quote:

Originally Posted by husky03

ffs-unreal-would you not be quicker just getting a replacement engine

Where is the fun in that? Plus won't learn anything new just swapping the engine.

Quote:

Originally Posted by muzikill

Thoughts on the chain of events that led to the damage?

Bearings goosed due to little lube, crank dropped on rotor side causing opposing rotor magnets to hit each other causing further stress on the crank leading to full rotor side crank siezure causing stress in the middle of the crank shaft as the crank siezure wasnt even.

Deffo not too little lube I can promise you that, we slapped it on like Mickey Rouke with a slab of butter ; )

andrewsmith · 02-11-11, 09:40 AM

SH

I'd be relegating that crank to paperweight and getting a new one!
Isn't that the 2nd or 3rd snapped one this year?

31-10-11, 11:35 AM	#171
muzikill Member Mega Poster Join Date: Jul 2005 Location: Dunfermline Posts: 1,712	If the main bearing had gone and with the amount of rotor damage there is you would think when you removed the rotor wheel the crankshaft movement would have been obvious. __________________ Learn to maintain your bike, take it apart, rebuild the engine & more (using better bolts ), drop it & fix it again! K3 Job c.v: Engine:remove/split/rebuild/refit. Replace:Gearbox,Fuel pump,Gaskets. Piston clean,rings. Overhaul:Throttle body,Injectors,Brakes,Forks. Remove/refit:Exhaust,Radiator,Oil cooler,Throttle,Air filter,Tank. Replace: Oil,Coolant,grease,brake hoses & bleed.

31-10-11, 08:56 PM	#173
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: SH2: The Rebuild (Image Heavy) Side to side or angular motion is normal, up and down motion = knackered __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

01-11-11, 10:07 PM	#174
squirrel_hunter Member Mega Poster Join Date: Apr 2005 Location: Sunny Swindon Posts: 3,579	Re: SH2: The Rebuild (Image Heavy) Part 18; Two halves don't make a whole: I have the answer... I spent a couple of hours taking the motor apart this evening. After getting a little heat on the piston I got the pins out and could go about the rest of it. This time the clutch was intact and the rest of the engine came apart easier than before. There were a couple of screws that were an issue last time but this time the impact driver was not needed. But before I give the answer out, and its a good one, a picture of my work bench. Its custom made, by me and my Dad. Its unfortunately about 6 inches too tall so I had to stand on a toolbox to get over the engine to split the cases. So here is what an engine looks like, and there are more bits in a box on the floor: And now the answer. Note, this is a picture not of two cranks: And the money shot: Awesome, a split crank. Quick inspection don't show a great deal of damage to the cases but I'd want to replace a couple of bits for sure. Need to clean it up properly and take a fresh look at it. So what to do... I have an Arc welder and Stretchie has a Mig welder, I think we can fix it. No? __________________ "A little enthusiastic?" May I add here, GG is awesome and I think I am in love with Stretchie...he rocks my world! SH2 \| 2MA \| GROM \| YSR

01-11-11, 10:18 PM	#175
husky03 Guest Posts: n/a	Re: SH2: The Rebuild (Image Heavy) ffs-unreal-would you not be quicker just getting a replacement engine

01-11-11, 10:53 PM	#176
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: SH2: The Rebuild (Image Heavy) Yeah, stick weld... use cast iron rods, the more carbon the harder it is so that must be better, right? Hog back into shape with angle grinder then file around, finish off with 60 grit sandpaper and spit. On serious note, this does definitely make me wonder about the wisdom of grinding cranks, as they don't normally snap there. I definitely won't be getting mine ground on big end to build a tuned motor with. Whether that be heat from the initial damage, heat from grinding, stress concentration changes from grinding whether internal or external... OTOH, split the big ends and post pics, let's have a look. Maybe a rapid seizure could cause the snap. Still not really ideal... __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

02-11-11, 08:46 AM	#177
muzikill Member Mega Poster Join Date: Jul 2005 Location: Dunfermline Posts: 1,712	Thoughts on the chain of events that led to the damage? Bearings goosed due to little lube, crank dropped on rotor side causing opposing rotor magnets to hit each other causing further stress on the crank leading to full rotor side crank siezure causing stress in the middle of the crank shaft as the crank siezure wasnt even. It still amazes me how much power comes from these little engines. Sent from my GT-I9100 using Tapatalk __________________ Learn to maintain your bike, take it apart, rebuild the engine & more (using better bolts ), drop it & fix it again! K3 Job c.v: Engine:remove/split/rebuild/refit. Replace:Gearbox,Fuel pump,Gaskets. Piston clean,rings. Overhaul:Throttle body,Injectors,Brakes,Forks. Remove/refit:Exhaust,Radiator,Oil cooler,Throttle,Air filter,Tank. Replace: Oil,Coolant,grease,brake hoses & bleed. Last edited by muzikill; 02-11-11 at 08:57 AM.

02-11-11, 09:06 AM	#178
maviczap Member Mega Poster Join Date: Mar 2007 Posts: 9,097	Re: SH2: The Rebuild (Image Heavy) It'll make a nice paper weight __________________ We're riding out tonight to case the promised land Make everyday count RIP Reeder - Jolly Green Giant and comedy genius

02-11-11, 09:40 AM	#180
andrewsmith Member Mega Poster Join Date: Apr 2010 Location: Newcastle upon Tyne, Just south of salad dodging country Posts: 7,750	Re: SH2: The Rebuild (Image Heavy) SH I'd be relegating that crank to paperweight and getting a new one! Isn't that the 2nd or 3rd snapped one this year? __________________ RIP Reeder 20/07/1988 - 21/03/2012. Always missed squire!!! Every year we meet old friends, gain some new ones, lose old ones and you always remember them all. “Live as if you were to die tomorrow. Learn as if you were to live forever.” Mahatma Gandhi

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