There should be a 1/4" ball in the plunger. Is it the right size?

The reason can also be on the clutch side. I have a pressure plate with a modified thrust button. Probably somebody modified it for a pushrod that was too short.

Will is right. On my cap the vent hole is between the chrome cap and cam plate on one side only. You could drill a small hole there. If the hole is above the cam plate, I would also expect that petrol is less likely to leak through the vent hole.

The oil drains back into the crankcase. When the oil is hot and the viscosity lower, more oil may leak past the pistons.

Thanks. I haven't blanked off the lower breather because it acts as an overflow in case the timing case is completely flooded and the oil would be pushed into the magneto otherwise. I looked at owners' handbooks and they mention Castrol Grand Prix only from 1938 when the closed head was introduced. ...

This is about my 1937 open head NH. I am still having problems with oil coming out of the lower engine breather in the timing case. When I used SAE 30 running-in oil there was no problem. Problems started when I switched to SAE 50 with a few drops. Now it's becoming colder, and there is always a pud...

The Draganfly web site lists all lengths, I think. But it is easy to see. If the old shorter pushrods are used with the single lobe cam, you have to screw in the valve adjuster fully or the valve adjuster isn't long enough at all. As always, the adjuster should be in line with the valve stem at half...

I have a 37 NH with the original carb settings. I have tried both, the original A6/664 as well as the single lobe cam (with the respective followers and pushrods). Both work with the original carb settings. I like to be believe that the twin lobe cam pulls better from low revs, but the difference is...

I use them, too; but I can't hear or notice any difference whether they are fitted or not.

Sorry, no answers. I only have an additional question on this topic, because I need to change the camshaft bushes on my NH as well. The bush in my timing case has an oil groove; the new bush from Drags hasn't. Should there be a groove?

Worn throttle slide?