Tim Berframe
ArboristSite Lurker
I have a 18 year old Stihl 025. Has less than 75 hours of use (3 cords / year for 10 years then basically nothing for past 8 years). Always started 3 pulls after sitting for a year or more - not this year. It started but ran terrible and was unusable. Opened the carb and it was plugged with green slime.
Assuming ethanol troubles, I just bought a new carb. Wouldn't start.
Changed fuel line, filter, checked intake boot(it is fine). No start.
Spark seemed weak so I changed coil, plug, and spark plug wire. Strong, hot blue spark. No start.
Changed base seals and sealed up bottom real carefully, new impulse line. No start.
Did compression test. 1 pull 60psi; 2 pulls 90 psi; 3 pulls 120psi; by 10 pulls 150 psi (this may be because of fuel now in the cylinder?) So, I have at least 120 psi.
I have good fuel supply - a nice white vapour with every pull.
The piston and cylinder look brand new. I can see cross hatch on the cylinder and the piston skirts have no wear or even discoloration on them. I didn't measure the ring gap cause I couldn't find a spec. Tiny bit of carbon on top of piston.
So, I have fuel, compression, and spark. That only leaves timing. The key on the flywheel is cast into the flywheel and is fine.
Pouring gas into the cylinder or into the air intake with a new, dry plug doesn't even try to kick. Dry base with choke and start lock etc etc like usual doesn't even try to kick.
So, my question is : Is it possible that the new coil is mismatched to the flywheel so that ignition timing is off? I have spent hours trying to find anything on line that would list specific pairs of part numbers. Unfortunately, I tossed the original so can't check part number. The replacement Stihl coil # is 400-1306. The book says the factory flywheel is 1123_400_1203. Is there a different flywheel to get me going?
Assuming ethanol troubles, I just bought a new carb. Wouldn't start.
Changed fuel line, filter, checked intake boot(it is fine). No start.
Spark seemed weak so I changed coil, plug, and spark plug wire. Strong, hot blue spark. No start.
Changed base seals and sealed up bottom real carefully, new impulse line. No start.
Did compression test. 1 pull 60psi; 2 pulls 90 psi; 3 pulls 120psi; by 10 pulls 150 psi (this may be because of fuel now in the cylinder?) So, I have at least 120 psi.
I have good fuel supply - a nice white vapour with every pull.
The piston and cylinder look brand new. I can see cross hatch on the cylinder and the piston skirts have no wear or even discoloration on them. I didn't measure the ring gap cause I couldn't find a spec. Tiny bit of carbon on top of piston.
So, I have fuel, compression, and spark. That only leaves timing. The key on the flywheel is cast into the flywheel and is fine.
Pouring gas into the cylinder or into the air intake with a new, dry plug doesn't even try to kick. Dry base with choke and start lock etc etc like usual doesn't even try to kick.
So, my question is : Is it possible that the new coil is mismatched to the flywheel so that ignition timing is off? I have spent hours trying to find anything on line that would list specific pairs of part numbers. Unfortunately, I tossed the original so can't check part number. The replacement Stihl coil # is 400-1306. The book says the factory flywheel is 1123_400_1203. Is there a different flywheel to get me going?