Dan Forsh
Addicted to ArboristSite
Quick re-post as I realised that I'd put MS220T not 200 in the title.
It's been a while since I last poked my nose into the innards of any saw, so I might have lost my mojo; someone has asked me to look at their MS200T with 'carb problems'.
It's the first time I've worked on this model and it's a fiddle little thing, but the carb is the same as any other, so I hoped that a repair kit would be the simple solution.
Initial symptoms were that it would fire on choke, then rev a little then die. Stripped the carb out and it's a Zama with anti-tamper on the high speed screw. Opening the carb up it looked nice and clean with nothing immediately obvious except I noted that the control lever looked too high (not level with the bottom of the chamber as we are told they are supposed to be).
I fitted the new parts and noticed that the new lever also appeared to sit high but thought I would try it and see first. No real improvement same symptoms. Went back in and had a go at adjusting the lever down. At this point I wasn't confident that setting it level to the bottom was really correct as it seemed to need a significant adjustment with the pliers to get it there. I did it anyway in the certainty that both the Stihl manual and a Zama general carb manual both said this was the correct position.
Reinstalled the carb and the saw would fire over on choke but seemed to be just firing on the initial charge from choke with nothing beyond that, as in less than a second when moved to half choke. It seems to me that the significant adjustment of the lever is no longer actuating the needle at all.
So out it comes again and I reinstall the original lever at the original position. Still fires over on choke nice and easy and fires up and will continue to run on throttle lock, but dies as soon as I touch the trigger to bring it off half choke. So now my finger tips are numb from pulling this thing out and putting back in and I'm in need of some suggestions.
I will add that I cleaned the air filter first time round and blasted the body through with carb cleaner, also replaced the fuel pickup filter. Can't see any issues with the fuel line and the tank vent seems okay too.
Any ideas? I don't have the facility to pressure test the unit.
Dan
It's been a while since I last poked my nose into the innards of any saw, so I might have lost my mojo; someone has asked me to look at their MS200T with 'carb problems'.
It's the first time I've worked on this model and it's a fiddle little thing, but the carb is the same as any other, so I hoped that a repair kit would be the simple solution.
Initial symptoms were that it would fire on choke, then rev a little then die. Stripped the carb out and it's a Zama with anti-tamper on the high speed screw. Opening the carb up it looked nice and clean with nothing immediately obvious except I noted that the control lever looked too high (not level with the bottom of the chamber as we are told they are supposed to be).
I fitted the new parts and noticed that the new lever also appeared to sit high but thought I would try it and see first. No real improvement same symptoms. Went back in and had a go at adjusting the lever down. At this point I wasn't confident that setting it level to the bottom was really correct as it seemed to need a significant adjustment with the pliers to get it there. I did it anyway in the certainty that both the Stihl manual and a Zama general carb manual both said this was the correct position.
Reinstalled the carb and the saw would fire over on choke but seemed to be just firing on the initial charge from choke with nothing beyond that, as in less than a second when moved to half choke. It seems to me that the significant adjustment of the lever is no longer actuating the needle at all.
So out it comes again and I reinstall the original lever at the original position. Still fires over on choke nice and easy and fires up and will continue to run on throttle lock, but dies as soon as I touch the trigger to bring it off half choke. So now my finger tips are numb from pulling this thing out and putting back in and I'm in need of some suggestions.
I will add that I cleaned the air filter first time round and blasted the body through with carb cleaner, also replaced the fuel pickup filter. Can't see any issues with the fuel line and the tank vent seems okay too.
Any ideas? I don't have the facility to pressure test the unit.
Dan
