I have a lees sachs 4.2 that i can not get to run right.I have to heat a plug up in the tiller to even get it to start,after it starts it will not run long also does not run good.Can not move throttle much it will die.after a while it will not start,can take the plug out and put it in the tiller and start the tiller and let it run a couple of min. and then we put the plug back in the 4.2 and on and on and on......I have set the needles from 1 turn out to 3 turns out and it makes no difference?????I give,anybody got any advice?????...THANKS...Jerry

rebuild the carb...

This carb was rebuilt about 3 years ago(i rebuilt the card) and was run by rcing1 then i let it set for 3years.The diaphrams are bad now?Would they dry rot????

No dry rot, they get stiff and don't respond fast enough....Take the diaphragm out and hold it by the edges...If it crinkles it's gone....

Rebuilding it will not be a problem,can the lever on the needle valve cause this type of running and also does anyone know the stilh saw # this thing came out of ....THANKS...Jerry

I built those engines for about 3 years and most were sold by Dick Bennett of B & B Specialties. They were not out of a Stihl saw but assembled
from original parts obtained directly from Sachs and subsequently Makita.

All 4.2 Sachs based engines use Mahle cylinders, some have an extension on the bottom that goes into the case, some are flush on the bottom....
My old chainsaw reference book shows a 120 super with a 49mm bore, look on the casting at the base...The number is cast.....49ZN2 or 49ZN4.....47 on the base is a 3.7...