rite dont know if anyone can help but ive got a 1wg that just wont run on cylinder number 4 , its had two engines in it and both wont run on that cylinder ( what are the chances of two engines in the same bike having the same problem ) ive changed the coil and cleaned the carb about 4 times but nothing seems to work , help

You had trouble with the first engine, then I read you were asking for cam positions on this engine ?
If the valve clearance is ok ( you must have done them when asking for cam lobe position) and there is compression and you have swapped plugs/leads around; it points to the carb.

Will it not run on 4 at any revs or only idle.?
Is the plug wet.?
If no other carbs; can you swap float + float valve/ slide c/w needle/emulsion tube/jet block from no.4 to another cylinder.?

Is the top cover properly on the carb inc the little o ring. ?
The slide should move up the same as the other 3 even if not running on that cylinder when engine revved.
You said in other posts; you checked the diaphram.

Can you access a compression tester.?
It may be 2 engines with low comp. on no. 4 but you cannot tell without a comp test.

With the engine running but airbox off spray some carb cleaner into the offending carb. If it fires then its a fuel / carb problem.
If it doesn't, check the plug is sparking. Pay attention the plug cap, unscrew it cut 10mm off the lead and screw the cap back on. If you have a spark at the plug.
Check compression. Checl the valve clearances for that piston, even if you set them before.