How to replace ignition coil on asthil 029

one of the wires will go to a stop switch as that will be the method of shorting out the coil to stop the engine

Remove the plug and place plug back in plug wire and set where it is close to touching a metal piece and start like you normally would, should see spark coming from plug, if no spark very likely the coil. If coil has omhs listed, disconnect coil and wires and test with ohmmeter

Disconnect the stop switch to rule out a problem here, if there is still no spark with the plug out and earthed against the cylinder, then it sounds like a replacment ignition unit is required

What about intake leaks and engine condition?

valve clearance should be 0.10 feeler guage
Flywheel 0.25 feeler guage

Hi, 8 thou. Regards Phil.

What you have to do is find out the gap clearence between the flywheel and the pickup coil (induction coil}. A quick and dirty measurement is to align the magnetic portion of the flywheel with the pickup coil. fold a mathbook cover in half and insert it betwenn the magnet and the induction coil. adjust the coil so that it is snug - not tight- against the matchbook cover.This should give you a better clearence for the induction coil to work.

if it has a battery
fit a good battery as the system may require 12 volts to energize the ignition system properly

check timming belt and it it is not turning this is your problem and if so this is zero clearence motor so there is also probley more dammage done to the motor

replace the coil it is breaking down