outdoorhunting

Somebody out there has gotta know. I'm building a 60 size GP Extra 300 S & powering it with a Super Tigre 90. I'm using a "Bisson type" muffler & the stock muffler screws are too long ( Italian motor) If I can get the size,then I might be able to order them. I think (a guess) that I need 3.5MM by15MM. Yeah I checked out RTL Fasteners, they don't have 3.5MM. Any ideas? Thanks in advance!!

aerowoof

super tigre used to use an almost unkown thread size here in the states,british whitworth threads,not sure if /when they changed to something else

R8893

My Feedback: (20)

I have drilled out most of my ST muffler mount holes and tapped them with the next size larger American (English) sizes. 8-32 works IIRC

outdoorhunting

That's what I usually do. The Italian motors apparently the screw threads into the engine head. There's not enough room to drill. The screw goes through the muffler into the cylinder.

bipeguy03

Supertigre Engines use an 8-24 for the mufflers in everything from the 60 and up. 50 and the lower engines use 6-24. Had this problem last year. you can buy pre packaged replacements from tower for like 5 or six bucks. little bit much but it takes out all the guess work.

Hope this helps!

wzak29

My Feedback: (1)

cut the screw

outdoorhunting

Can't. The threads don't go all the way to the head. I could use washers, but it would look like "fido's butt".

jjscott

Try www.microfasteners.com

They seem to have 3.5mm, but only one pitch. See page 5.

Jim

Clay Walters

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFY16