Oil stud arrived today, fitted and no leaks... but nothing is ever straight forward is it... ran for a few minutes then started smoking like a good 'un... guess it's pulling oil in from the valve stems or some such?? A job for tomorrow now I think, need a couple of beers to drown my depression
Interesting, my 350 is a sort of 1950 scruffy twin of yours. I bought it as a basket case but have not had much spare time lately so its been a slow reassembly in fits & starts. However I had a burst of activity last week and got it running again. Like yours it started smoking once it got warm.... I'm not going to worry yet as I still have the wiring to invent and a few other details (e.g. terrible chain case) and I suspect that after a few shakedown runs I'll find plenty of of other issues. One of my concerns is that it has a cut and shut "trials" silencer that is a bit loud. I was tempted to go high level but looking at yours the speedo cable routing round the outside doesn't look ideal. Could it go inside the line of the pipe?
Thanks Steve and Pete, lots of routing and wiring issues to fix myself yet so 'maybe' is the best answer... Didn't look like a great flow back to the tank I have to say but I have over filled it, the manual said 4 pints I think but I had to stop at just over 3... so if it's wet sumping what's the solution? Oil pump off and shown the air line? Rather hoping so in some ways, didn't really want to strip it all the way back down again...
Had another look today... flow of oil back to tank is more of a drip than a flow... what should it look like? Also had another thought, the gauze on the bottom oil strainer was in bits when stripped down, I replaced with new gauze but a finer mesh, could that be a cause?? It wasn't a lot finer but a bit none the less.
The oil pump in a single is essentially two pumps in one. The small one pumps oil into the engine, the larger one pumps oil back in to the tank. So the large pump should have no problem removing all the oil from the sump just bringing up what the small pump delivers to the engine. It should look like a straw in your mouth that has picked up the last few drops of your favourite milkshake, milk with a few bubbles. Can't think the gauze would cause any problems
Any air leak on the return between the pump and the strainer is critical. Cracked pipe, gasket behind pump, and the extra little round one where the pipe comes out on the crankcase face and sealing of the balls in the pump itself. The scavenge pump has many times more capacity than the supply pump so once the excess is returned on start-up it has a lot of air in it so it's an intermittent flow in normal circumstances. Not sure about the fine gauze. When the bottom plate is in place there's not much encouragement for the oil to find it's way into the return line and the rotating flywheels probably don't direct it to the bottom of the cases. Quite a few competition types have used scrapers to help guide the oil to where it needs to go. Nev
Coincidence or not... removed the gauze altogether, fixed a leak in the rocker oil pipe and changed the oil from 20/50 to SAE 50 - something has worked, seems to be running great now not a puff of smoke... Pretty much just the wiring to complete now and I'm away... managed to locate a clutch cover but have had to make a brake pedal as a temporary fix, just hope my welding holds out!!
Just been for the first spin out on the road... superb One significant fault though on check-up back home... obviously she didn't like all of the gearbox grease and decided to spit some out (see photo), any ideas why?
Apart from that, not looking too bad if I do say so my self ...in to the fettling stages now I hope...