As far as I understand, wet sumping can be present in two ways. One way is when a bike is parked for a while and the contents of the oil tank drain into the sump as was the case in my A50, but another way is when the return of oil to the tank doesn't keep up with supply during running, resulting in smoke and oil coming out of the exhaust. The more the engine revs the worse it gets. The latter is what I think is happening in my B40. There is little change in the tank oil level and I can see a steady flow of oil when idling, and dropping the sump plate allows perhaps an egg cup of oil to run out. So is there a scavenging issue and therefore a need to renew the pump or am I missing something?

Hi everyone
Does anyone know the size of the grease nipple fitted to the speedo drive of an early B40 (1962/63)? Its about 3/16" across the threads and guessing 30+tpi. Possibly 2BA? Its about the same size as on my A50 but its a coarser thread on that.

I'm about to fit turn indicators to my A50 and I'm toying with using LEDs and a warning buzzer. Has anyone fitted anything similar? How loud does the buzzer have to be to be heard above the engine and is it wired in place of a warning light? Is a buzzer compatible with an LED flasher unit?

Cheers

Is it possible to refurb the petrol filler cap from my B40? The gasket is hard and crumbling but I can't see how to remove/replace it.

Has anyone got experience of removing a pilot bush and replacing it with a screw in jet? I have trouble starting my 1968 A50, and everything points to insufficient fuel. It starts fine if I put my hand over the air intake or screw the airscrew fully in. It needs full choke with no throttle to start even when warm. First thoughts are either a blocked pilot jet or air leaks, but once started it runs and idles fine, if slightly hesitant at initial pickup. What effect would there be if the 25 pilot bush was replaced with a 30 pilot jet?... or am I barking up the wrong tree?
...... I've richened the mid range already by lifting the needle a notch and fitting a 3 throttle slide, which has stopped the spitting from the carb and overheating, and prolonged use of choke.

I don't find the Haynes wiring diagram of much use for my 1961 B40. I'm particularly interested in the connections to the ignition switch. Can anyone point me in the right direction?

There are three pipes on the oil union on my '68/'69 A50, one short one which I think connects to the rocker feed and two long metal pipes. Can someone tell me which receives oil from the tank and which is the return?

Ratio describes adding a breather hole to a rockerbox inspection cover to improve breathing in a unit single. I wonder whether anyone has experience of this or have any comments to make about it.
I have just unblocked the breather/drain hole in the inner timing cover of my B40 and with the outer cover still not replaced, it's quite noticeable how much air passes through it as the engine is turned over.

I have oil in the outer timing case to the extent that it oozes out of the kickstart. I'm not clear whether its from the gearbox or engine. According to Ratio its normal for some oil to get into the outer casing but it should drain into the sump through a hole near the bottom edge of the inner casing. I've found what was probably the said hole, but it has a tiny brass plug blocking it off. For the record its an early distributor model that hasn't been on the road for many years.
Secondly, there were no gaskets on the joints just goo. Is this correct?
Any thoughts would be welcome.

Does anyone know of anywhere that stocks B40 piston rings? I bought a set of new Italian ones but they are too wide to fit in the bore once fitted to the piston. Seems like its a common problem. I've tracked down compression rings, old stock, but haven't found an oil scraper ring to fit; its +60 thou. There must be some somewhere.
I've got my fingers crossed.

The old head gaskets for B40s are 48 thou thick whereas the new ones are 36 thou with a raised lip around the cylinder. Does anyone have any views on why the gasket thickness has changed and pros and cons of the two types?

I'm fitting new cast iron valve guides to my B40. The first one was cooled in the freezer first, to shrink it and it broke 3/4 in. The second I fitted at room temp and went in no probs. I've now ordered a replacement to complete the job. Has anyone got experience of whether they should be cooled or not before fitting?

Checking over my recent b40 (1963) purchase I notice that the carb is an amal 376/231. According to Ratio it should be 376/253. I've managed to start it but its as rough as hell. Can anybody suggest whether this carb will work or do I need to change it. I don't want to start tinkering with settings if its a no goer. Thanks in anticipation.