Whilst on my weekly coffee run through the hills my M20 started to make an unusual noise, but still running okay. I decided on caution and turned around and headed home. While doing so the noise stopped and everything seemed okay.
Back in the shed running the bike on the stand through the gears trying to get the noise to reappear I noticed the ammeter was not showing a charge.
I then removed the end cover off the generator and sure enough it wasn't rotating, a stripped fibre gear. Obviously the noise was the generator gear acting like a chain saw and stripped the teeth down until it lost contact. Had I known that I could have finished my run.
I obviously need a new fibre gear. My magneto is MO1 dated 4/45, which is about right for my bike. It has the fibre gear with the clutch set up, I am not sure if that's right for my model or a later setup fitted. I do have a new old stock solid fibre gear which I believe is from early models.
Can anyone (are you there Ian) advise what's best. The clutch setup is obviously to protect the fibre gear, although it didn't help me, or should I just fit the solid gear. It is tight on the shaft so it will take some careful fitting, probably have to strip the magneto to fit.
Being in West Australia the chances of getting a gear here is probably nil, so I would most likely have to source one from the UK.
Is there anyone in the UK that sells parts for these, must be on email and accept paypal and post to Australia.
Also when fitting a new fibre gear do they need grease on them of leave dry.
Thanks in advance.
email (option): tknalder@iinet.net.au
I can supply you with a good used fibre gear and I also have an improved seating washer for the clutch spring..(the arms of the spring sit on the washer and it's prone to distortion/wear after extended use)..
The question is why did the teeth strip in the first place?...It infers excessive loads so it would be best to check that your dynamo is turning freely...When refitting a very small quantity of light grease applied to the gear teeth is all that's needed...If you have an earlier fibre gear and the only dimensional difference is the width of the teeth (earlier ones are narrower) you could use it OK...I guess it's your decision there and you have to consider why the gear was widened in the first place...
Contact me off forum reference supply of the parts...Ian
email (option): ian@wright52.plus.com
Thank you for replying Ian.
I restored my bike back in the mid 80's before internet days and as parts were hard to obtain locally the fibre gear which was second hand went back in. I guess 30 plus years the teeth wore out until eventually failed. The generator does spins freely but when being driven and charging I guess there is a certain amount of load on the gears.
With todays internet worldwide shopping has changed things significantly for the better.
I will certainly keep your offer in mind, I only just found out I might be able to get a new one here so waiting on a response. I never checked the width of the teeth on the solid one but will do as wider teeth would be stronger.
email (option): tknalder@iinet.net.au
Hi you could try Bils Bikes and bits at Birdwood In SA I don’t have his number but I am sure he is on the web, I may have one in the shed somewhere.
Cheers
Beware of new fibre gears unless they are NOS or you know their provenance...There are new Indian gears out there and the tooth form is not correct..(that seems to be an Indian speciality)...When running they whine like crazy due to this problem and they don't get better over time...I know, I tried to 'run one in' over a number of months without success...In the end I removed the ear plugs and fitted a NOS gear I'd come across...No further problems....
Even a good used gear would be a better option by far...Ian:gear: :gear:
email (option): ian@wright52.plus.com
I tried fitting a new one (India made I am guessing) and the center hole was a little to big and the the gear would not stay centered on the clutch. So went back to the original one and all is still OK.
Were those fiber gears ever replaced by metal ones?
I came across some and wasn’t sure it was legit.
I looked at my NOS solid gear, fibre with steel centre and it is the same width as the later clutch type, being 1/2". I would rather fit the clutch type but if all else fails then in it will go, at least the bike will be running again. I did see Indian ones on Ebay and wondered about them because they are not really that cheap especially if inferior. I will take Ian's experience and advice and avoid them. Still got a couple of irons in the fire so a new genuine or UK manufacture might turn up.
email (option): tknalder@iinet.net.au