MS 440 tuning

Van · Jun 1, 2004

Hi, I am new on this forum but have been lurking for awhile now. This is a great forum with a lot of knowedgable folks contributing and I have learned alot here. (end of sucking up and on the the question) I have a question about the carb settings on my 440. Last week I ported out the muffler from 3/8 stock to 1/2", then adjusted the carb. The saw seems to run about 20% better. The first question is - The carb has these limiting adjustment screws with red caps, can or do they need to be removed? The saw was set with a tach and is idling about 2750 and runs 13500 wot with no bar on, getting about 13000 rpm with the bar installed, 20" bar. I run my mix at 45 - 1 The second question Should I richen it up some more and lower the rpms? I have had it a year and dont want to fry it. Thanks for any and all help.
Van in AR

lucky · Jun 2, 2004

Van, welcome aboard!

About the mix ratio and the rpms; Sounds ok to me but I don't know it all. I'm sure you'll get as many different answers as you'll get replys.
I have found a cheap and easy way to tamper with stihl's limiter caps. Get a size #4 I think??? machine screw. It can be left or right hand thread. Or get the stihl tool(left hand thread) You can thread this screw into the limiters. Once it's threaded in tight you'll be able to twist the limiter until the plastic tab lines up with the slot in the carb. Then pull out. Adjust the carb as needed then replace the limiter caps to prevent the screws from falling out. Good luck and enjoy AS! John

Lawn Masters · Jun 2, 2004

So thats how those things come off, I've always used a set of needle nose pliers and just pulled them off. I guess theres a tool for everything.

rahtreelimbs · Jun 2, 2004

Sounds like you are fine to me. I would suggest that you tune the saw in the wood, then make a note of what the RPM is for future reference. I would also check the rpm only with the bar & chain on the saw. Change to a good synthetic oil like Maxim K2 or Mobil 1 MXT2 at 32:1 and you are good to go!

Van · Jun 3, 2004

Thanks for the replies!!!
If I do change from Stihl oil to one of the better synthetics do you think that 40 to 1 will be enough to protect the 440? (I also have a 038 Super that I bought new in 1983 thats still going strong and it specified 40-1) My dealer told me to just mix the 50-1 for both saws because the oil has gotten better and it would also be OK for the 038, I have been fudging on that by mixing the bottle to 2 1/4 gallons and getting a 45-1 ratio (just figured as long as im not fouling plugs what would it hurt. But if 40-1 would be better I will do that. Since the muffler port has been increased and the carb richened up the saw screams, after the muffler mod cutting tests I changed the rim sprocket from a 7 slot to a 8 slot. All I can say is WOW: blob3: It now outcuts a friends of mines MS 460, by finding and reading the posts it has really peaked my interest. Wife was woke up the other night at 11 PM by the sound of me tuning saws in the farm shop: D Now I want a 066, or a big Husky, Congratulations: YOU guys have created another monster-----and I love it.
Van