[Thomas]

The reason why heat can separate parts are the different material expansion coefficients for the body (aluminium) and the nut (probably brass). The former is about 25% larger. You can't damage the metal with a heat gun or the oven. The temperatures are far too low. I would start with the oven and see if it works. 
Thomas

[Peter 100]

Thanks John
How hot do you have to get it, just warm or quite hot. I am a bit worried about damage. Would putting in the oven for a bit be sufficient?
Pete

[singleminded]

Heating will help remove the large nut that holds the jet block in place. I have found that the gasket between the nut and body seem to get glued together, i have had to pass a 1 inch bar through the body before to get it free.
When stripping the carb to clean the jet block you MUST warm the body so that the jet block can be LIGHTLY drifted out, if you try to get it out cold and it is a good fit in the body you can distort the whole jet block and give yourself more trouble.
Good luck.
John Hood

[Peter 100]

Thanks Thomas i will have to remove it and give it a try with a bit of heat.
Pete

[Thomas]

Hi Pete! Cleaning maybe with an interdetal brush but I personallywould dismantle the carb. For the union nut a heat gun might help.
Cheers, Thomas

[Peter 100]

Hello to all.
Bike will start but virtually cuts out right away. I think fuel stavation ie blocked somewhere. Is there a way to clean passageways with carb in situ. Also i have had the carb off in the past and could not manage to undo the union nut at the bottom of the unit, it was rock solid, any suggestions how to undo??
Many thanks.
The carb is fitted to 1934 model 9.
Pete