Ms660 - no spark

[welwell]

Alright fellow Arbs. We have a ms660 (never really liked it tbh) that has developed a fault. There’s no spark, we’ve tried the usual stuff, new spark plug, checking the gap between flywheel and sender, wires, ht lead, all connectors are good on the kill switch. It’s proving to be a right head scratcher. Any ideas people? 

[Stubby]

27 minutes ago, welwell said:

Alright fellow Arbs. We have a ms660 (never really liked it tbh) that has developed a fault. There’s no spark, we’ve tried the usual stuff, new spark plug, checking the gap between flywheel and sender, wires, ht lead, all connectors are good on the kill switch. It’s proving to be a right head scratcher. Any ideas people? 

Coil failure ?

[Treetom15]

+1 for new coil maybe? I’m sure on L&S engineers they’re not crazy money, just make sure you get a genuine stihl part. 

[Stubby]

The only other thing , and its rare , is the flywheel has lost some magnetism but I still think coil . 

[Ian C]

I would go with coil, non genuine aren’t that expensive and easy to fit.

[spudulike]

The 660 has the polymer flywheel and you need to pull the saw over fast to get a spark so before lashing out on any expensive parts....pull it over hard with the plug out, connected to the cap and earthed on the cylinder.

DO it in subdued light as the 660 is one of those saws that you need to pull it over fast to get it to spark.

 

If there is no spark, check the condition of the flywheel and see if the magnet part of the flywheel has good strong magnetism and no damage as I have seen a 461 with similar and it was the flywheel that had taken a knock and not the coil!

 

If that checks out, check the HT lead out...continuity from the cap to the laminate, it should conduct, if not, remove and check the HT lead, if it conducts, the coil is probably fooked.