Help needed

[JED]

I have got to the point that I need to ask the silly questions. Along with a very good friend of mine we have just finished restoring a 1917.
The whole bike has been gone through including the engine and gearbox the bike starts second and third kick everytime and sounds great,
the problem we have is that its seems to be get very very hot on the rear cylinder very quickly, we have checked the timing, checked all
the ignition side of things, we have checked everything we can think of.
Can anybody suggest what we have missed. I know they run hotter on the rear but this is too hot. (We have straight 50 oil in the bike!).
Many Thanks

Jed

[23JDCA 808]

Running lean on rear cylinder? Too little fuel or an air leak at intake manifold? Piston or piston ring clearances too tight?

[Tommo]

Have you checked the ignition timing on both cylinders?
Do you have a 45 degree mag that has a 45 degree interrupter ring fitted?
You may have a mismatch of 42, 45 and 50 degree parts in your magneto
To do the above tasks correctly you will have to fit a degree plate and have both of the cylinder top mounting plugs out so that you can accurately measure where both pistons are exactly when the ignition contacts open.
If your bike is an electric model and not a mag model disregard what I've said above.

[JED]

Hi Bill,
Thankyou for your reply, we have checked both plugs and they both are a little on the rich side, definatly not on the lean side.
We have also checked the manifold and all is sealed and tight.
We have done some more tests and to give you some kind of idea with both barrels cold and a running time of 5 mins, front cylinder
value side 87c piston side 74c. Rear cylinder valve side 192c piston, piston side 111c.
Many Thanks again
Jed

[JED]

Hi Peter,
Thank you for your reply. Its a electric model.
Many Thanks
Jed