wvengineer
ArboristSite Lurker
Hello all first post, and a quick question.
Anyways MS 361 stock saw. Chain runs at idle. I initially thought it might be the clutch springs, but then I started thinking that the idle was too high. I have also been feeling like the rpm's have been too high at WOT. I'm using an automotive tach set to 4-cyl. The instrument I'm using is meant to be connected to the coil. So for a 4 cyl I'm thinking that whatever it's reading it's dividing it by two. If that's the case then my saw is way over. The idle is like 5k and WOT is around 20k or so. I know it seems like half of that would be about normal. Something's wrong here. And just to be sure we're on the same page I'll explain why I'm doubling my rpm reading for a 2-stroke. For a 4 cylinder every 180 degrees of crank rotation get's a spark on one of the cylinders. Since this thing is made to measure from the - side of the coil then it's reading all cylinders. It would be dividing the reading by two because it would read spark on at least two cylinders for every 360 degrees of rotation. The 2-stroke is one for one. One spark for every 360 degrees of rotation. So where did I go wrong in my thinking? If my thinking is right then I'm in trouble because I'm going off of the service manual and turning the LA screw all the way down will stall way before it reaches 2800. Again is my logic just wrong?
Thanks for the help.
Anyways MS 361 stock saw. Chain runs at idle. I initially thought it might be the clutch springs, but then I started thinking that the idle was too high. I have also been feeling like the rpm's have been too high at WOT. I'm using an automotive tach set to 4-cyl. The instrument I'm using is meant to be connected to the coil. So for a 4 cyl I'm thinking that whatever it's reading it's dividing it by two. If that's the case then my saw is way over. The idle is like 5k and WOT is around 20k or so. I know it seems like half of that would be about normal. Something's wrong here. And just to be sure we're on the same page I'll explain why I'm doubling my rpm reading for a 2-stroke. For a 4 cylinder every 180 degrees of crank rotation get's a spark on one of the cylinders. Since this thing is made to measure from the - side of the coil then it's reading all cylinders. It would be dividing the reading by two because it would read spark on at least two cylinders for every 360 degrees of rotation. The 2-stroke is one for one. One spark for every 360 degrees of rotation. So where did I go wrong in my thinking? If my thinking is right then I'm in trouble because I'm going off of the service manual and turning the LA screw all the way down will stall way before it reaches 2800. Again is my logic just wrong?
Thanks for the help.