Good day all,
I'm after a bit of chainsaw repair advice. I've got a lovely little MS200T that's recently developed a wobbly exhaust. I've noticed in the past couple of years that the bolts occasionally seem to come loose, but they've always tightened up and the exhaust has held firm again for months. I recently took it in to the local dealer for a general service and repair. When I collected it they said they'd also had to put an exhaust bolt in as one had dropped out, (unbeknown to me). The first time I used it when I got it back it ran sweet as a nut for a couple hours and then the bloody exhaust came loose again, by the time I noticed and checked it was missing a bolt already. I ordered a couple of genuine stihl replacements, put the missing one back in and ran it again. This time it only lasted a couple of minutes before they both shook loose. Conclusion is that the threads are obviously stripped in the holes, (didn't feel right when I tried to tighten them so I had an idea of the problem already).
I'm somewhat reluctant to take it back to the dealers again as I've spent far too much money in there recently. Also I discovered that the remaining exhaust bolt in there when I got it back last time was nothing like the original stihl type. It was much coarser and looked like some kind of self tapper. So someone must have known there was a problem with the thread but it wasn't mentioned to me. Plus it seems like a crude repair attempt;- re-tapping the hole or using a helicoil would surely be better. (To be fair to the dealer place it may not have been them that put it in as I've had it repaired elsewhere in the past).
So my question to you knowledgeable chaps is;- how easy would it be for me to install helicoils myself? From my brief research it appears that is the best repair to this quite common problem. What exact size of helicoil do I need? If I have to drill out the holes how accurate must I be, i.e. can I use a hand-held drill? As I don't own a drill press unfortunately.
Thank you. Sorry about the long-winded post again, this was my attempt at being succinct!
Simon