throwing sparks

[Big ben]

hi folk s. this is my first post so bear with me if my terms arnt up to par .ive got a sthil 036 installed new rings and piston when i started it the saw started throwing sparks like crazy  from the muffler is this normal break in or have i messed something up?         thanks for your much needed help

[Al_Smith]

Oh Oh ,your doing one of two things .The lesser of two evils is blowing carbon out the muffler .The worst is stripping the lining off the cylinder .Best pop the muffler off and investigate .

[Big ben]

well the piston looks rough around the edge s whats that mean

[Stutz]

Sounds like you need to take it apart.

[Al_Smith]

A few years back I had a PM 610 Mac come to me that needed some attention .The thing had a bad oiler that allowed lube oil to get sucked into the crankcase causing the muffler to plug up .As a result the piston had pulled a lot of aluminum .

That saw blew a lot of sparks,most likely the aluminum burning  or badly passing fire due to stuck rings .

The fix which was half fast at best was to clean everything up and reassemble because repair parts far exceeded the value of the saw .Believe it or not that thing is still plugging away .

Some times you can save a saw with a screwed up piston/cylinder ,some times not .

Now as far as that piston,a metior from Baileys is only around 35 bucks .Fact is I just got one myself.It's not the quality of OEM but it doesn't carry that high  Stihl price tag  either . It should work but how it will hold up is anyones guess .

[Big ben]

well i think the top ring was froze the piston is pinged up pretty bad as well as the jug whats the best thing to do help!

[Rocky_J]

Find the source of the air leak before rebuilding it again? 

[Big ben]

ok put a new jug and piston in seams to be running fine but the carb needs adjusting whats the best way run the screws in all the way and back out a little at a time ?

[Rocky_J]

This might help-
http://www.madsens1.com/saw%20carb%20tune.htm
 

[Al_Smith]

That Madsen thing is a pretty good guide .As long as you hear that "4 cycle " blubber you're pretty safe .To check ,just pull the plug after it's ran a while .

The plug should be a light brownish color .If it's white you are set too lean .If it's black you are too rich . Better rich than lean . I tend to set mine a tad too rich .Then again in all these years I've never cooked a saw engine .

Funny ,some people simply because they don't know any better set them so they just scream at wide open throttle out of the wood . They actually cut worse when in the wood  set too lean . One old rule of thumb that will never change ,it takes fuel to make power .