Have a Stihl TS 420 cut off saw. Primarily use it for cutting metal decking and steel work. Have owned the saw for a couple years now and within the past two months I have had to replace the muffler bolts twice. The same bolt snaps inside the block and has to be removed using an easy out bit. Last time I tried to use hi temp lock tite and it happened again. Any advice on how to fix this issue? Has anyone else had this issue with Stihl equipment?
I own a masonry company and have around a dozen of these saws. Those bolts have broken off on nearly every one of them. These are great saws, but it is a fatal flaw and it never happened on any of our older 400's. I have no luck with easy outs, so I end up having to get replacement jugs. It stinks having to put a new cylinder on a saw that runs perfectly except for the deafening noise. Stihl gave me the replacement jugs for free on a few of them but they are not going to stand behind them any more so I am considering going with Husquavarna from now on.
miterman Husquavarna parts more money .More plastic parts on saw.
The next time you replace with a new jug, try taking the bolt out and replacing it with a grade 8 or aircraft quality bolt and see if that gives you anymore life.
Are you using a torque wrench when reinstalling the bolts ?
You could install a new gasket using stainless steel bolts tig or wire weld a piece of stainless welding rod.... a jumper between the two bolts so they can't back off.
Problem is that the OP's muffler bolts are breaking, not backing off - at least that's how I read it. It may be that the bolt is over-stressed which would lead it to fail once it had been through a few dozen cold->hot->cold cycles. Is there any space available to use a slightly longer bolt with a spacer over the shank to take up the additional length..? That's the usual solution for exahust bolts breaking.
Yep, long as you can as Nige suggests, and if at all possible use studs and nuts, always works better for me, though I haven't used them on cut off saws, just motorcycles engines.