My understanding is that in 1956 the primary drive was moved outboard slightly to accomodate the new FERC. This involved a new longer crankshaft drive spindle (1140-56), wider LH crankcases (1400-56) and a longer gearbox mainshaft. Since you think your bike might be a late registered '55 model is it...

The ones I got from Club Spares last year are 1.5mm thick and have been no problem in my overheating prone VB for the last 6000 miles.

Colin, Here's a better view of the brackets on my '49 rigid single which might help with placing your holes. Rigid Single.jpg There should also be a reinforcing plate (6565-35) between the two top bolts inside the toolbox - not listed by Draganfly but easy enough to fabricate. Rigid toolbox reinforc...

Most of the exhaust clamps back then were steel bands NO fins at all.. Nev 39 (top) 46 (bottom) SQ4.jpg These are the original parts from my 1939 SQ4 (top) and my 1946 SQ4 (bottom). The fin removal of 39 clamps appears to be identical for left and right exhaust which would tie in with the 39 parts ...

Colin,

It looks to me that the holes in the top of your toolbox are in the wrong place - they should be closer to the lid. The picture is a Sq4 but I think it's the same for a single.

Pete

Liam, 1431-37 are the crankshaft main bearings which have a 1.125" bore. The bearing for the gearcase between the coupling gears and the primary drive should be part 1432-37 which is identical to the main bearing except its bore is 1.124" i.e. one thou smaller. Unfortunately 1432-37 is uno...

Nev It's also very important to get the small end boss central. The small end boss was central to the crankcase join and the big-end was smooth with no discernable vertical play. The relined standard bore and piston were smooth with little wear. Do you see any evidence of something being where it sh...

I am surprised that the roller used in place of it doesn't show damage. Has the inside of the timing pinion worn away the timing case? Paul, Both the outer bearings are lipped and it appears to have been shimmed so as to get the desired end-float between the two lips. Hence the timing pinion is hel...

There's nothing 'positive' as such to locate the crankshaft and the lipped rollers don't seem mind about dealing with end-float Simon, I seem to remember that the end-float on BSA twins is controlled by the timing side bush which is pulled onto the crankshaft by the timing pinion. The actual float ...

My VH engine has always been mechanically noisy and harsh so I have finally had the engine apart to investigate. I found nothing unusual until I removed the crankshaft and found it had three roller bearings rather than the outer driveside bearing being a deep groove ball bearing. driveside main bear...