Trying to start a Stihl MS210 which has sat unused for 5 years. Fuel supply seems OK, but there doesn't seem to be any spark. LT seems OK - ie cut-out wire only connected when switch in stop position. Any suggestions on how to diagnose the problem?

Jonathan, July 2010

Thanks for suggestions. I thought I might be in for a new coil too, but checked the spark plug and found no continuity between the electrode and the cap that pushes into the rubber boot. Strange. Anyway, I gave the cap a good rub with emery and got continuity with around 20kohm resistance (which sounds about right). Refitted the coil and now was getting a good spark. Reassembled and saw started straight away! I think the lesson here is always replace the plug before spending cash on a new coil.

Jonathan, July 2010

If the earth cut out wire is ok ( you could just try disconnecting completely from the unit ) it may require a replacment unit, very strange as i thought it was a new machine, Stihl used to have a life time warranty on ignition units, not to sure if that is still the case, have you tried a proper spark tester rather than the spark plug as this is probably soaked in fuel by now? air gap should be 0.3 mm between unit and flywheel, make sure you have a good earth for the unit body, this is unlikly but make sure there is good magnatism in the flywheel.Always remember electronic units work off speed of rotaion, so you need to give it a good crank over. Good luck

Husqvarna man, July 2010