I have a Royal 40 with stripped muffler threads. Could someone please tell me what size bolts these things are assembled with?
I can probably retap and use longer bolts if I can figgure out what size they are.

Royal .40
I'm not sure what size they are, but I would guess that they are metric! I had a Royal .40, but as I remember the muffler was not tapped, the engine case was. The screws went through the muffler and into the engine. If you retap, it shouldn't matter about the bolts. Just use either Std or Metric...what ever tap you have, because your going to in-large the holes anyway. Sorry, not much help, am I? Just trying to help anyway.
Suptter

hey Suptter,
Tryin beats the heck out of nothin don't it?

Avinut,
It sure does! I'll do whatever it takes to keep flying myself!

The screw is metric M6

Hi!
No way they are M6!
That's a 1/4 of an inch! You most mean M4...(4mm)?


Regards!
Jan K
Sweden

Well ,guys,if it was English I would guess it as a 6/40. So what does that come out in metric?

Duh!

I guess you are right. I must have slipped off my keyboard again.
M6 is just too large, and m4 is correct.

Although 6-32 might fit as well. I guess what'sw where I got the 6.

Well, I gave up on the size and retapped to 6/32 so we can close this thread. Thanks all!

I re tapped at 7/37 worked good