Stihl FS 45 won't start

[Buzgod]

Aussierod,

The ignition module of most, if not all, stihl equipment is considered to be disposable and even in their own Stihl dealers there is no standardized way of measuring the AC volts as a trouble shooting tool. That being said it could be that ignition module. If I had that FS 45 in my shop I would run the gamut of vacuum/pressure tests on the crankcase and def check out the muffler/spark arrestor.

 

[aussierod]

Aussierod,
def check out the muffler/spark arrestor.

Dang nabit, I've been used to the old style square mesh screen.

I wiped all the grease away from the FS45 exhaust outlet and had a closer look.

BINGO!! :wink:

OK, so this model has a screw in insert with a round mess inside that can be taken out with a 15mm socket.

Thing runs like new now. Customer got a new carby in the ordeal as well.

Ow well, live and learn.

Thanks mate :thumbsup:

 

[woodworker34]

I am completely flumoxed (Olde English word). My Stihl FS45 suddenly stopped whilst in use about 6 weeks ago and would not restart. So I started checking and found no spark. I replaced the magneto coil, ON/OFF switch (but that is OK) and spark plug and now I get a spark, but still no start. My next action was to buy and fit a new carburettor in case the small fiddly diaphragms had perished or split and at the same time cleaned out the fuel tank and filter ( but already quite clean) and removed and cleaned the silencer/muffler which here in the UK has no spark arrester. Compression is good and there are no signs of any crankcase leakage. As far as I can tell, the magneto/spark timing is OK as the flywheel magnets are centred on the magneto as the piston comes to top dead centre. What's left? Do I just junk it and put it down to experience having more or less completely rebuilt it ?

Any ideas anybody? Grateful for any insight on this intractable problem.