Quick impulse line question

[fletcher969]

Hi all,

I'm chasing what I'm sure is an air leak somewhere in my MS361 (erratic behavior I cannot eliminate via carb adjustments), and I don't have easy access to a compression and/or vac tester, so before I retrieve said tools and tear it down to check the oil seals, piston, rings, etc., I was wondering if the impulse line should swivel/rotate 360 degrees where it attaches to the the crankcase/cylinder? I've never actually replaced an impulse line on these Stihls, but I did notice when I was checking my impulse line (which is solidly attached to the nipple) that I can rotate it like one might the hands on a clock. In other words, the nipple itself rotates in its seat. Is this normal, or might this be a source of air?

Thanks.

 

[president]

Yes, if it rotates there must be free/open space for it to move seal it

 

[fletcher969]

Yes, if it rotates there must be free/open space for it to move seal it

Thanks. Any suggestions what I can use to seal it that will endure all the vibration? I would think some epoxy might do it, but that would also make the nipple a permanent fixture of the crankcase (not that I can think of a reason off the top of my head why that would be a problem).

Also, should I assume the nipple seat/slot has worn, or is something else indicated?

 

[Chainsaw Jim]

Jb weld works perfect for nipples.

 

[lone wolf]

Nipples should stay firm when checking.

 

[KenJax Tree]

[emoji1] you said firm nipples

 

[Cj genever]

I always keep some permatex right stuff sealant in the shop. I've used it to seal plastic carb nipples on vintage saws. Works great and is elastomeric, so it can deal with the vibes. It is a decent glue, but much less permanent than epoxy. I haven't found an application this stuff doesn't work for other than where you want aerobic to avoid clots

 

[fletcher969]

Thanks everybody. I picked up some Permatex along with a compression gauge and vac hand pump. I can always use the epoxy I have on hand if the Permatex fails at some point.

 

[o8f150]

Nipples should stay firm when checking.

every nipple I have personally check doesn't start firm but after a few minutes they firm up when checking

 

[lone wolf]

every nipple I have personally check doesn't start firm but after a few minutes they firm up when checking

OK, that is a lot more accurate.