Identify gearbox

petemark · Post by **petemark** » Sun Apr 19, 2009 11:55 am

Hi all
I recently aquired a heavy weight single which is a bit of a mongrel,
It has a twin down tube frame which I think is 1960 or later, engine
no starts 57/18s****, it's coil ignition, has old tin primary
chaincase,dynamo electrics, V5 states Ist reg 1983, classed as a historic vehicle.
I will be contacting the dating officer to try to pin down its
origins.
meanwhile the gearbox requires some work & I need to determine if
it is a Burman or an AMC box, the no is M17409 can anyone assist ?
What are the visual differences between the two gearboxes.
Thank you

dave16mct · Post by **dave16mct** » Sun Apr 19, 2009 7:00 pm

It's an AMC gearbox by the number. Look at the oil filler, it should be held by two screws. Cheers Dave.

wilko · Post by **wilko** » Mon Apr 20, 2009 2:30 am

Coil ignition with dynamo electrics?? Hmmmm.. i think i'd be converting to magneto ignition if i were you, even tho coil is original?

56G80S · Post by **56G80S** » Wed Apr 22, 2009 11:06 pm

Pointless remark really, but the plate on the AMC is the access to the fit the clutch cable to the operating lever. Easy to snap the hole in the flat cover off if too energetic. On the Burman it is a screwed cap. Be aware that thereare broadly two Burman boxes.

Mine came with an AMC which I've now swapped for the Burman I refurbished and is "correct" for the model year.

I've now learnt that chasing originality is less important than getting out and riding it! The AMC has a slicker change but I found the clutch more vulnerable. The Burman seems tremendously robust box, but not easily hurried. Others may differ in this opinion.

Johnny BEdited by - 56G80S on 22 Apr 2009 10:07:14 PM

Don Madden · Post by **Don Madden** » Thu Apr 23, 2009 3:10 am

I pretty much agree, Johnny B, but my '56 scrambler was my desert sled for decades & I fitted the AMC 'box as I could bang on the shift lever when my foot was close enough without using the clutch as I was hanging on with hands feet & tail didn't dare loosen my grip to pull any levers. Desert terrain is very rough but I don't use the bike to compete now so am returning the original gearbox to its rightful place.

Cheers, Don.

petemark · Post by **petemark** » Thu Apr 23, 2009 11:22 am

Thanks to all who answered my query, I have just had a reply from the dating officer who
has confirmed the gearbox is AMC which left the factory in 1957 in a 600 matchless, oh dear
I did say it was a bit of a mongrel.
Thanks again