AJS & Matchless Owners Club

No problem with your english, I think it's far better than mine. Annars kan vi snakke skandinavisk, jag är svensk, men bosatt i Estland Thanks for pointing out about about the non return valve, will check that.

More oiling troubles. For the first time I had the engine running for a while. 5-10 minutes. It's the second time I have it running, first time just very briefly. Proper oil return, but under valve covers it's totally dry. Bottom end is 55, cylinder heads probably 52-53-ish. Two screws valve covers, but no oiling grooves in the rockers.

I can see several reasons for dry valves-rockers: 1. wrong or incorrectly fitted head gaskets. 2. Not been running long enough to pump up oil to the heads. 3. Cylinder heads and rest of engine don't fit together. 4. something else?

More likely to be the metering jets blocked in the heads. They have a very small hole, less than 1mm. I use a very fine guitar string to clear them but I think you'll have to remover the heads to clear them. Early 55 had a different oil metering jet (next to the oil filter in the crankcase) then quickly changed back to the rotating oil distributor 022385. Perhaps check that if you've got the distributor that it's OK. My 55 twin had the distributor and I had no problems.
Dave

Let the engine run for ten more minutes (while oiling with an oil can). Still no oil to the top ends. Removed one cylinder head. There's no metering jets in these cylinder heads, channels in the heads are circa 3 mm. Totally dry in the channels. There's plenty of oil in the cylinder bores, perhaps even more than needed, but I'm not an expert. From the emgine number mine's on of them with a metering jet instead of rotating oil distributor, so next thing is to check that area. I think I have the parts to convert if needed.

After what I've read there are three different rotating distributors, with holes 3/64' (1,2 mm); 1/16' (1,6 mm) and 1/32' (0,8 mm) The one I found in a box is 1,2 mm. Is there a reason to enlarge the hole to 1,6 mm ?

I would leave it at 1.2 mm for now. When you fit it you must use the correct copper sealing ring under the cap. If you use a fibre washer you can end load the distributor.
Dave.