[singleminded]

What year is your bike? What is the condition of the plug? have you tried a new plug?
Do you get a spark from the HT lead if it is held near to the head ie about an 1/8th inch,a lot of the old mags won't jump a big gap but they are fine.If the spark at the plug or lead is OK then your carb may be blocked.
If there was a lot of oil in the sump I would have expected your bike to disappear in a cloud of smoke,mine does if I don't use it for a week or so without disconnecting the oil feed pipe.
The tell tale on mine does not pop out much but the oil pressure on my gauge is OK and have run it for many hundreds of miles like that..A roller/ball bearing type engine does not need a lot of oil.  John

[VicYouel]

Some  questions....... was the oil indicator firmly out and was oil returning? Were you using old fuel or new and was petrol tank "pet sealed?"

Have you checked points gap and timing? May have slipped/settled.

[Steve_M90]

The bike (Model 90) was started after 10 year lay-up. MagDyno rewound. Oil replaced in engine and gearbox. Ran well initially but with the following observations: a occasional popping noise (perhaps coming from the carburettor), vapour and dark fluid (for a while) from exhaust connection to the cylinder block, one exhaust has more gas flow. Engine has probably run for about 20 minutes including a 300 yard run. Now I can crank the engine through tdc (not easy but possible compared with before running it) and the engine won't start. I think I had too much oil in the system when I first started the engine as some oil must have drained into the engine before I topped the tank up - not sure this is an issue. Question is: what can I do to determine the issue or do I need to strip the engine to look at valves and piston rings.