Tune up?

[dodge man]

How often do you need to take your chain saw in for a tune up? I've got a Stihl that is about 3 years old and it just doesn't seem to start and run as well as it once did. I kind of bogs down once and while, and is hard to keep running at times. I blame half of it on the lousy quality of gas.

I've change the plug at least once and the air filter a couple of times. I really don't want to mess with the carb but I half rebuilt a lot of carbs on cars in the past.

 

[xyz123]

If you rebuilt car carbs you got it made. These things are so simple to rebuild. Complete kits $7-$12 if it was needed later on.

Check your tank gas filter and lines for cracking that could be a air leak. Check your impulse line etc.

It might just need a little L or H adjustment and idle.

Saw model?

Todays ethanol in gas stiffens the diaphragms up where they dont work right.

Most places say at least 89 octane min, I try to stay 91-93 octane, link on subject. http://www.madsens1.com/saw fuelmix.htm

Basic's of carb tuning link Saw Carb Tuning

 

[rswyan]

What he said ..... they are easy to rebuild, and if you have already rebuilt an automotive carb, I gotta think it would be a piece of cake for you.

I just had to do the carbs on an Echo Power Blower and a Stihl 031AV chainsaw .....

The Stihl I actually got the carb kit for and rebuilt it, and the Echo I just took apart and cleaned the internal filter screen inside the carb (crudded up) ..... probably actually rebuild the Echo with a kit this winter.

This was the first time I tore into any type of carb .... :thumbsup:

 

[dodge man]

Thanks for the links, that helped. I'm guessing its the low speed screw. It doesn't idle great, and when you start to cut with it, it often bogs down and dies.

 

[xyz123]

Could be L, but could also be a stiff diaphragm. I had one do as you describe, running out of fuel in the cut bogging down to nothing because of stiff diaphragm.

Another good read on fuels etc. Information on Engine Seizures

 

[dodge man]

I ended up turning the screws out about a 1/4 turn. I also bought some 93 octane gas and tried it. What ever the fix, it runs a lot better. The problem with fuel in my area is you can get pure gas, but it is only 87 octane, if you go higher octane, it almost always has 10% alchol.

 

[Kubota 2350]

I ended up turning the screws out about a 1/4 turn. I also bought some 93 octane gas and tried it. What ever the fix, it runs a lot better. The problem with fuel in my area is you can get pure gas, but it is only 87 octane, if you go higher octane, it almost always has 10% alchol.

If I had a choice between pure gas at 87 octane and premium with the alcohol, I'd run the pure 87 in my saws.

 

[easygo]

I thought higher octane gas burns cooler, but I don't know how the ethanol figures into that.

I have a Stihl that I bought six years ago. I had to replace a fuel line and it went to the shop for adjustment once. I could only guess at the proper setting but they have the knowledge and digital RPM thingy to set it properly. I asked the guy about getting a new plug. He said if it runs good no real need. It runs like a champ now.