My friend bough a Mk1 CRM off e bay some months ago. It was a bit of a bargain. The only down side was that it is a bit noisy. The noise is of a kitchen mixer/blender type that raises and lowers with engine revs(really hard to describe) He has had the engine rebuilt by a professional, who found nothing wrong but the noise is still there.
A fellow Mk1 owner suspects that it may be the balance shaft bearings, which I have also suspected as the bike is otherwise running fine.
Is it possible to change the bearings:
1) with the engine in the bike.
2) do the cases need to be split.
I would like to help him but have a limited attention span. Unless the job is done and dusted in a day it will lay open for ever.
Thanks

I think you are right in the balancer shaft bearing as it will make a hell of a racket on its way out.
you dont need to split the engine or remove it from the frame, just remove the clutch casing and basket, and the rotor on the oposite side. The next thing is the problem, the bearing will almost always need to be cut out with a dremel, unless you can heat the case up and knock it out but very unlikely.
Try doing a serch as i am sure i did a step by step last time i did it. Good Luck, Jon

make sure you check the balance shaft before you replace it with new bearings,if the shaft is damaged mine had an inprint of the bearings on one side you will more than likely need a new balance shaft as well or the noise will re appear very quickly
shaft was about £67.57 seal £4 needle roller bearing £18 all plus vat from lt
shaft(£35) if you can wait for six weeks from japan

yes you can do it in place
and yes the bearing is a pig to remove

If the shaft is worn/damaged. Has anyone turned the damaged area down and fitted a larger internal diameter bearing

Just a thought - haven't looked into bearing possibilites . Do I remember someone making a bronze bush to space out the turned down area

i looked at doing something similar,i am sure it can be done but quite a bit of grief,i took the cowards way out and bought the parts
originol poster seemed to implie no patience so he may struggle going that route

Thanks for the advice. I'm glad that it can be done with the engine in the frame.
I've done a search a looked through most of the tech area but have drawn a blank on your write up Jonorow.
I have however gleaned a reasonable amount of info that should make the job easier.

Hi eddie, i have just checked myself and your right, all i got was a mention that i had done it and then went into how to remove the clutch basket, so i will post that to help you.
You will need a flywheel puller to get the rotor off too (M27x1)

i have just done my balancer shaft so i will give you a run down.
- drain coolant and oil (no need to remove the waterpump cover)
- remove exhaust (not essential but makes it easier)
- remove kickstart lever and front coolant hose
- disconnect the oil pump cable and hoses (may be able to leave these in place, dont forget to plug the hoses)
- undo the case bolts and remove case (should come off with no problems, just push the kickstart shaft in at the same time)
- place in gear and remove the 5 clutch bolts.
- remove the clutch plates (be carfull of the last narrower plate and spring plate, these must be on the inside (MK3/AR only?))
- haynes like refit (reverse of removal) just becarefull when putting the new gasket on, mine slipped of the stud and i punched a perfect hole just above it so had to use sealant to block the hole!
Hope this has been helpfull. Jon

There are some tools I made when working on my project on Pg1 of the write up in 'Motards/Specials'.

dont forget to re-bleed the pump when you connect it---sorry if stating the obvious

Thanks for the help.
I recently fitted a new clutch in my Mk3. I discarded the 2 thin plates when fitting the EBC clutch.
What a difference this made. Before it was a pain to find neutral and almost impossible to start in gear all because the clutch was dragging.
I will sort out with him what he wants to do but at least it is all achievable and should not break the bank.
With regards to the M27x1 puller is there any other way of getting the flywheel off?

I bought a simple little tool 20 years ago for about £5 ' super little tool thats been a gods send over the years . i expect a google search should reveal a supplier of these tools for not a lot money and they are mostly a common thread on most bikes .
Regards Mike

I have tried and failed in the past to remove a flywheel with out a puller, and failed almost ever time!. Racespec sell them fairly cheaply. JOn

This shows the wear in the balance shaft it is no wonder the bike was making such a row.

UGLY

SNAP, i have one exactly the same, luckily i had a spare so changed it. There is one on ebay at the mo, so might be worth buying that rather than a new one. Jon