Mcculloch Super pro 125c can't set Low jet and idle screws correctly

[Ghostbandido]

Hi everyone,
my name Ghostbandido and although I'm new to this forum, I've been reading and learning about chainsaws for about 6 years with all the wealth of knowledge everyone brings here. I've been collecting chainsaws for about 7 years and own about 12, from a small arbor Echo,a Stihl 066,a McCulloch Pro Mac 850 Super, and the final one...Mcculloch Super Pro 125C.
It's in fantastic condition. It started right up, but then died out. So I changed the spark plug, and I reseated the H and L and brought them out to to 1. I started it right up and it screamed ridiculously and I hit the kill switch, I thought the old fella was going to blowup. I opened the H and L to about 1/4 more and it did the same.
I remember the H and L were seriously pulled out to about 6 turns on the H and about 3 on the idle screw. Maybe that is where it needs to be. I am seriously timid to mess with it again until I know what's the right way to set this beast. Any advice for a newbie is appreciated.

Thank you kindly

 

[Woodslasher]

Sounds like it has an air leak, I'd check the intake boot, impulse line, and crank seals. I've had the pleasure of running a few 125's and I have one of my own on the bench, and they should not need to have the screws that far out. Or, check the idle screw and/or carb butterfly. If it has more than a 1/16" or 1/8" gap between the butterfly and the carb bore then the saw could just be running at partial or full throttle all the time.

 

[heimannm]

Young Dan is wise beyond his years, you have an air leak and you need to find it before you cause irreparable damage.

I would start with a close examination of the intake boot and the impulse line.

Mark