MK2 balance shaft - what to do?

[kernow crusty]

Hi, Ive had a search and couldnt see anything that directly answered this.
Im finally getting the Mk2 engine rebuilt (discovered knackered mains growling and crunching away). As Id quite like to go and use the bike for a nice long time, Ive decided to sort the bottom end fully. The balance shaft shows signs of wear, not horrendous, but not pretty so hears the query:

I see some have sourced new balance shafts, this year even, can anyone give me directions to a source? (Looks like Japan, and yes, I know they arent cheap).

What happens if you dump the balance shaft? I like the ploddy bottom end of my CRM and its rather civilised road behaviour, so I suspect losing the shaft gives me more vibes and maybe less plod?

Any other suggestions? I see the recent mod of sleeving the shaft, but to be honest, Id rather spend the extra and get a new one.

Regards kernow crusty

[knackeredMk1]

See - viewtopic.php?f=20&t=5536

EddieEvans has removed his balancer shaft. As I recall there is a little more vibes that arn't noticable off road but are noticable on road. I suspect that the engine is freer to rev up but slightly less tractible,as you suggest. Whether anyone can notice this is another matter ............

[Eddie Evans]

If you get the part no. you can get a price here then check with LT as they can be cheaper.
http://www.davidsilverspares.co.uk/part ... rt-number/

I fitted a new shaft and bearings to mine for the chatter marks and noise to come back less than 2000 miles later. Don't know what caused it, I am sure that I had lubed the area during the rebuild possible wear in the clutch needle rollers, emulsified oil.

Peed off I took the balance shaft gear off replacing it with a spacer. So the balance shaft is still fitted but no longer spins with the engine.

The bike is used purely for trail riding and I have not really looked back. I do however think that long road rides would start to become a problem.

On initial start up there is a lot more vibration but this does smooth out once it warms up and to be honest I don't notice it anymore. It has full knobbly;s fitted so its not that smooth on tarmac anyway and once off road engine vibs are not noticed.

I would say that it has lost a small amount of grunt but it is definitely more snappy and acts like a 250 smoker should.

Future plans I have is to get a balance shaft ground down to the standard needle roller sleeve dimension and fit that. Think the needle roller is 2mm wider which could cause a problem with the seal but got to be worth a try. Repair would then be a simple new standard needle roller.

[fallenmikethebike]

Hi Krusty, long time no hear, seasons greetings,I hope you get the old girl sorted soon.
I wonder if just removing the weighted portion of the shaft would be of any benefit, so much less balancing effect, but the same shaft, and a lot less load on that shaft.
Thinking more, just a machined shaft would do the same job.
Mike

[back off road]

ive got a spare ,dont no how good it is , does anyone no the original measurements so i can check if its worn or not

[kernow crusty]

Thanks for that chaps, hmm...decisions! Think I'll price a shaft then decide!

Cheers KC

[Mudfacetony]

I have disconnected the balance shaft on my mk3. I removed the gear and had a space made the innder diameter of the shaft (made it a snug slide fit), the outer diameter was about 10mm bigger. 44It vibrates more than my mk2 (whih still has th balance shaft). I like both, the mk3 is more responsive and the vibes are not that much more than the mk2 and a cheap fix