Carb balance reduce thread size

[FeckityFeck]

Bonjour, someone has drilled out the M4 hollow bolt that is used to balance the carbs (where you would screw in the copper extension pipe engine side of the carb) and replaced with an M5 Helioil.

 

How does one go about reducing thread a size back to a hollow M4.

 

 

 

 

 

[Gixer1460]

Make up a new copper extension pipe with a M5 thread or make a plug with M5 thread and then try to re-tap with M4. Could be tricky as M4 - M5 has not a lot of material between the cut threads.

[jensvonbustenskjold]

+1 on a new pipe with m5. 

Is this for all 4?

 

[Wolf]

Self cuting inserts come in diffrent wall thickness that can take it back diwn