Stihl saws...not running

[jj3500]

Anyone having these issues?

I own 3 saws, all which are well used and well maintained.

the two i'm having problems with, Stihl MS066 and Stihl MS 361, they were literally running fine. Bucking for hours. I shut down to move my splitter, I come back to it, 5 mins later, then it now won't start. I've changed plugs, NGK, changed gas, dumped the old gas contents, new mix and new 93 octane. Pull and pull,...zip. ?

I ran into this a few hours earlier, i bought plugs and that cured the problem. Now that its happened again, i'm thinking its something else. Bad gas, i know the gas isn't the same anymore but i literally just bought the new gas yesterday. New 2 stroke oil out of a sealed container.

anything that i'm missing that someone can recognize quickly?

thanks for any input.

One of the last things i want to do is give my saws for 4/5 days to a shop and then whack me for ~$100/per saw.

ouch!

 

[Clarkbug]

What do your air filters look like?

The fact that it happened earlier isnt a good sign. What did the plugs look like when you pulled them?

Can you pull the muffler to check the piston for scoring?

 

[Jags]

The fact that it is two saws at the same time might point to a common item - fuel. If there was crude in the old fuel it may have been drawn into the carbs (on both machines). Unfortunately simply dumping the old and refilling won't clean out the carbs.

Can we assume that you have spark on both machines?

 

[Clarkbug]

Might want to swap fuel filters out too. If they are plugged up with any crud that was in the gas can, that could be part of the issue.

 

[The Weimar]

Lots of little variables to check, as the previous posts have called out. If the fuel is new, check the fuel filters swimming around in the tanks, check the fuel line also, as a small crack will lean it right out, like trying to drink through a cracked straw.. Check the air filters, check to see if you have spark. Some older machines/coils can get temperamental when they get older, and if you run the saw hard and get it really hot, the coils will start to throw inconsistent current and may cause the saw not to start, once you shut it down. Other than that, there isn't too much else going on there.

 

[TreePointer]

Good advice already posted. Covering some more issues:

When applicable, have you changed each saw's configuration for cold weather operation?

When you finish operating your saw, crack open the fuel cap and listen for sucking sound. I've been around more than one 361 that has reached vapor lock condition which prevents restart after being set down for a while. A quick fix is to remember to crack open the fuel cap immediately after stopping the saw to relieve the low pressure condition in the tank.

 

[jj3500]

great tips! thanks gents. I'll get a look at all the mentioned above.
its snowing and ~27 degrees out. I'll sit it out for a bit.

thanks again.