(Stihl 192tc) -1 muffler screw + hi temp epoxy + hi temp loctite + new screw = dimpled cylinder wall

[askfault]

Yep. Don't do what I did.

Stihl 192 tc about 1 year old lost a muffler screw while in use.

The saw was stopped and I went to get a new screw at a nearby dealer.

He kept mentioning something about the wall being so thin, but, knowing what needed to be done I just asked for a new screw please.

The screws given were too long so I went back and requested to get replacements that were like the old ones.

He gave me them and I picked up hi temp epoxy and loctite 650 degree F (max temp) and..this is what I did wrong.

The epoxy in a small amount was mixed up and rolled into small earthworms that filled 1/4 of the threaded holes.

Then for "good measure" (yeah right....) I put a blob of hi temp loctite on the screws that were already in the muffler and ready for install (destruction).

I gently took turns tightening one screw then the other till both were secure.

Leaving it to set I was thinking that problem was solved and I went back to the work location for a big surprise.

All geared up I gave the handle a pull to start it up..

It was stuck for some reason.

I tried a few times and then the words from the dealer came to life in my head.

something like, "be careful, the walls are thin.....(walls are thin) ((walls are thin)) (((walls are thin)))....

After teardown completely I now have a dimple on the inside of the cylinder wall that seems to have toasted it (too much epoxy pressurized under the force of the screw gave a new meaning to thin walled cylinder)



Don't do this!!

Next step, is it possible to grind or file off the dimple on the side of the cylinder or will it cut through the nikasil? (sp) coating?

Thinking to get a new cylinder but wanted to make sure nobody else tried my...."repair" and ended up looking like an idiot.

 

[old guy]

Warning noted.

 

[astnmacgto]

Stuff like that happens in the automotive world every so often except it's usually caused by coolant/oil/liquid thread tape/ and other sealers getting behind bolts except it can crack blocks or destroy heads, when something gets behind the bolt something has to give. Just a curiosity thing but what were you trying to do with the epoxy? I'm guessing the threads were compromised?
ADLM

 

[askfault]

Stuff like that happens in the automotive world every so often except it's usually caused by coolant/oil/liquid thread tape/ and other sealers getting behind bolts except it can crack blocks or destroy heads, when something gets behind the bolt something has to give. Just a curiosity thing but what were you trying to do with the epoxy? I'm guessing the threads were compromised?
ADLM

Yes sir, threads seemed a bit compromised.

 

[astnmacgto]

And now you know, every time I make a mistake (which is more often than I care to admit) I just have to remind myself that I now know exactly what not to do next time.
ADLM

 

[ms290]

I have one of these saws, and your experience has been duly noted. As for your cylinder I'm not sure what you SHOULD do, however I know what I would do. My solution is to try trimming that dimple down. It's already broke so if it breaks more, well, big whoop.

 

[joe kool]

the 192t i have (not sure if exactly the same) needed a muffler bolt, i noticed after thinking to use a am one that what was called for was a self tapping type, why this was needed was way beyond me, ( and the dealer cause i asked at the time)
was so long ago i do not recall if he gave me a warning about just screwing it in bare, and not TOO tight, i am sure there would be a spec for the torque?
found looking for carb tuning
the shop manual or owners i d/l had given the instruction how exactly to do it, mine was not easy to adjust either, although i use it for only small stuff, it seems to start and run well now
http://prntscr.com/gwy33x
the repair book said mine was 2005-2009
leaving info for people who may look here
i got this from instruction manual tho