Welcome to ArboristSite.com! Log in or Sign up to interact with the ArboristSite community.

ArboristSite.com Sponsors

  1. Please see this post Click Here Please ask questions if you have them!! I hope this is going to be great for us all.
    Dismiss Notice

Stihl MS 440 max tuning

Discussion in 'Chainsaw' started by tygerorange, Mar 8, 2009.

  1. tygerorange

    tygerorange ArboristSite Lurker

    Apr 7, 2008
    Likes Received:
    I am trying to get as much power as possible out of my 440. I have already tweaked the muffler and put a high flow air filter kit on it. What else can I do to get more power? I am lookin into getting it bored out. Any thoughts?
  2. timberwolf

    timberwolf Addicted to ArboristSite

    Aug 29, 2002
    Likes Received:
    Get the saw ported.

    You can't for practicle purpose get a chainsaw cylinder bored out, the cylinders are plated unlike a cast iron bore in a truck. boreing and honing a closed to cylinder is difficult and few if any performance shops will touch such a job. Even so when boering out 2mm over the port timing and such gets altered and you would need to reestablish porting numbers and sizes.

    With machene work a 046 cylinder can be fit to the 044 to give it 77 cc or a 046bb jug to give it 82 cc.
    Last edited: Mar 8, 2009
  3. drunkenredneck

    drunkenredneck ArboristSite Member

    Dec 18, 2006
    Likes Received:
    Are you doing the work or haveing it sent off??

    Well you could start by pulling the limiter caps so you have enough tunability for modifications, then widen the exhaust port and polish it, clean up the transfer ports, open up the intake port, degree the saw to see what kind of timing numbers the factory has it at, adjust the transfer intake or exhaust to maybe get some better timing numbers, remove the base gasket to get some compression, lessen the squench, lighten the rotating mass ie. flywheel clutch, open the muffler up more, mill the piston and cylinder to up compression and or generate better fuel mixture, moly coat the piston skirts so they slide easier, open up the windows in the piston so the air will flow easier, index the plug for a better spark, add auxilary ports to the cylinder wall, put ceramic bearings in the bottom end, hone the guides in the bar so the chain slides easier, hone the rough edges in the throat of the carb to generate a more consistent undisturbed airflow, pull the keyway in the flywheel and adjust the ignition timing, match the case halves to the cylinder ports and remove any casting imperfections in the case halves, make a new cover for the muffler so that you can in effect supercharge the cylinder fuel mixture with the harmonics generated by the exhaust gasses, build a tuned pipe, build a velocity stack for the saw, experiment with clutch drive sprockets to get the best cut time, go to a thinner bar oil, race chain, sprocket tipped bar, make a pipe for a muffler and run an outlet to a miniture turbo then to a metal intake aft of the carb to turbo charge the motor, alky, heck if your this far you mine as well just drop in a big block.....I like to help but come on use the search button this stuff is on here everywhere. you can email me if you want detail about some of the stuff, and trust me there is plenty more. :jawdrop:

Share This Page