stihl 076 bogging down

[symamania]

Gday guys question for yall.

My 076 I use in my CSM is acting strange I can cut 2 slabs with it perfect then for some reason it keeps bogging down and barely wants to run the only time it seems to run properly is when it leans out on low fuel. Ive had it in to the Stihl dealer and after $250 later its still the same!!!!!!

I run it with 25:1 fuel mix from their recommendation. I also got a new fuel cap for the 076 because it was leaking  out of the grub screw on the cap. I got a new one and that still leaks is this a common thing with those caps or whats the deal.

Any ideas of why my saw is running this way? The chain is nice and sharp and pulling good chips when its running right.


cheers

[mad murdock]

How is it outside when you are milling? Maybe try it real early when it is cool to see if there is any difference.  I know my 075 does not like it much when it is in the 90 deg range outside or above.

[symamania]

thanks for the reply murdock it was probably around 16 deg Celsius today so wouldnt think it was a heat problem 

[mad murdock]

What kind of gas are you using?  In the states, a lot of states have mandated ethanol blends, which dont work as well as straight gas. To get past this some states allow premium grades to be pure gas (no ethanol) some do not.  Not sure what you have there, but sometimes grade and quality of fuel can affect engine performance in certain conditions.  Another thing is check to see that the saw is clean of buildup around the flywheel, airpath for cooling air.  If you are milling a lot with it, the real fine dust likes to collect in the saws cooling air path and thwt really makes it run a lot hotter than it should, as sawdust is a great insulator, not a conductor of heat, stopping the heat transfer from the metal to the air. A good thorough cleaning with compressed air on regular intervals is a must for a milling saw to keep it running at its optimum. This will obviously require taking the starter cover and sometimes the top cover off. As well as the bar cover etc. i do this a couple times each milling season if i am doing a lot of milling. Otherwise i do it once a year if i am just using the mill occasionally throughout the year.

[sawguy21]

Have you checked the spark arrester? It could be plugged from running that rich oil mix.

[ZeroJunk]

It is not out of the realm of possibility that the ignition is starting to break down from heat and when it cools back down it will work OK for a while.

[HolmenTree]

Sounds like a fuel tank venting problem or the fuel line filter pickup not positioning  right.
Not familiar  with these saws but sounds like the leaking grub screw in the filler cap is the fuel tank vent like other saws from that era.