I have a stripped thread on my Commando barrel. Specifically the 3/8 stud between the barrels.
Is it possible to drill and tap for a helicoil? Will the cast iron require any special precautions or tools?
If its not a "diy" fix, what needs done to repair it.
Thanks in advance
Dave
if it's in the base flange
- Log in to post comments
I thought...
... he was talking about the one between the pushrod tunnels. The one you need a slim 3/8" drive socket to get at. There isn't a lot of meat at the bottom here and it often breaks through into one or other tunnel but a helicoil should have enough at the top end to hold. The main issue would be getting it true with the existing hole.
- Log in to post comments
Thanks, it is the one at the…
Thanks, it is the one at the top. Drilling and tapping shouldn't be a problem as I can set it up in my bench drill. I was more concerned about the cast not being able to be tapped.
- Log in to post comments
Cast iron is easy to drill…
Cast iron is easy to drill and tap, the high carbon content acts as a lubricant (but still use one on the tap) and the swarf is a fine powder so a good vacuum after the thread is cut is a good idea.
- Log in to post comments
Thanks all. I didn't…
Thanks all.
I didn't realise that the thread was BSC. I was just going by the exploded-parts list on the Norton site.
I haven't pulled the barrels yet and would have checked when I did. But its good to have a sanity check.
- Log in to post comments
Stripped thread
Helicoil is the way to go. I have done this before no problem.
Paul
- Log in to post comments
About 30 years ago I fitted…
About 30 years ago I fitted a Recoil insert for one of the cylinder base studs on my 99 , Still working perfectly , still have the kit, probably never use again. What size is it? Where are you based Dave.?.
- Log in to post comments
then the stripped thread is actually in the crank case, not the barrels