13-09-2020, 07:31 PM
Ian, you are a genius!
The pitch of a 2BA thread is 0.81mm and of a 5mm thread is 0.80mm, which explains why the 2BA screw fitted albeit a little loosely. I only have a 5mm taper tap but it has cleaned up the first few threads such that the G&L needle now readily enters part way. No obvious metal swarf emerged, just some grey powder suggesting that it is just severe corrosion on the threads. A plug tap should clean the rest of the thread and I should be in business.
Thank you again for taking the trouble to look out your carburettors and for your very helpful advice.
John.
The pitch of a 2BA thread is 0.81mm and of a 5mm thread is 0.80mm, which explains why the 2BA screw fitted albeit a little loosely. I only have a 5mm taper tap but it has cleaned up the first few threads such that the G&L needle now readily enters part way. No obvious metal swarf emerged, just some grey powder suggesting that it is just severe corrosion on the threads. A plug tap should clean the rest of the thread and I should be in business.
Thank you again for taking the trouble to look out your carburettors and for your very helpful advice.
John.