I know this isn't a chainsaw, but I think a few of you might use this McGyver -ness.
Once these TS420 Stihl muffler attachment threads get stripped, then you tap them for 6mm bolts and they get stripped again, you start to run out of options.
Drill through the fins behind the exhaust flange. I use a 1/4" first, then a 3/8" drill bit. Try not to get too shallow, or too deep. Take care to get the angle right, and steer clear of anything that you can damage, like transfer port access covers. After Its drilled take a garden variety 026 bar adjuster nut, which has 5mm threads and slip the little end into the end of a 6" long Piece of common 3.1mm fuel hose. Then drop It down the hole and rotate the hose to align the threads with the mufffler screw. Walla... you've got a round anchor In a round hole that won't spin, and It has the correct 5mm threads. Once you get the muffler screw started, just Pull the hose off and tighten the piss out of It as much as you want.
I chamfer the holes and file flat the exhaust flange , and the muffler Sealing surface.
I've done this on a few TS500i's too.
It's way cheaper than a new cylinder.
Once these TS420 Stihl muffler attachment threads get stripped, then you tap them for 6mm bolts and they get stripped again, you start to run out of options. Drill through the fins behind the exhaust flange. I use a 1/4" first, then a 3/8" drill bit. Try not to get too shallow, or too deep. Take care to get the angle right, and steer clear of anything that you can damage, like transfer port access covers. After Its drilled take a garden variety 026 bar adjuster nut, which has 5mm threads and slip the little end into the end of a 6" long Piece of common 3.1mm fuel hose. Then drop It down the hole and rotate the hose to align the threads with the mufffler screw. Walla... you've got a round anchor In a round hole that won't spin, and It has the correct 5mm threads. Once you get the muffler screw started, just Pull the hose off and tighten the piss out of It as much as you want.
I chamfer the holes and file flat the exhaust flange , and the muffler Sealing surface.
I've done this on a few TS500i's too.It's way cheaper than a new cylinder.
