Stihl MS280 no start (no spark?)

[CarlMs280]

Hi, I have a Stihl MS280 that I bought new about 4 years ago.  I was working fine last fall, but would not even try to start yesterday.  I assumed it was a plugged up carb even though I did drain out the gas and ran it dry last fall.  I took the carb off and took it apart, sprayed carb cleaner in all the holes.  The diaphrams looked to be ok still (as flexable as I think they should be).  I put it back together, got some fresh premium, mixed it 50 to 1 and filled it up.  Put in a new plug.  Still no start.  Sprayed some (flammable) WD40 in the carb.  Still no start.  Pulled the plug, put it in the boot, ran an alligator clip from the ground of the plug to the fins on the engine, switch on - no spark.  (did it in a dark room to make sure there was no spark)  I need to get a T-27 screwdriver as I can't remove one part of the cover my my T-27 socket (to deep).  Once I get that off I will try to check the coil.  (I have a DMM).  Am I going the right way or have I missed something?

Anyone know where I could get a service manual or wiring diagram for the 280?

[joe_indi]

Remove the starter cover.
Check if the flywheel-ignition module gap is too much. Or whether it was too little (Your are looking at a flywheel replacement then).
If the gap is too much, use  newspaper three leaves thick for a temporary setting.
You could also disconnect the black lead from the ignition module.This removes chances of earthing from a stripped stop lead.
See if you get a spark now.

Joe

[boobap]

I've got a MS270 manual, but not the 280...can't imagine there is much difference  ??? . I do however, have the 280 IPL if you want it...PM me your email address.

Todd

[CarlMs280]

Ok, I got the T-27 screwdriver and pulled the cover.
Are newspapers standard thickness around the world?  It was snug with 3 thicknesses of newspaper but I could still move the paper around when the flywheel magnets were aligned with the coil.
I have some vague memory that you are not supposed to use a steel feeler gauge for this sort of thing?  If not, is brass OK?

I checked the coil resistance from the spark plug electrode to ground: 1.47K ohms.

I pulled the black wire off of the ignition module.  Sill no spark.

Probably the ignition module?

Thanks Joe, for the wiring diagram.  Not much to it (unlike a car).
Carl.

[Cut4fun]

I just use a business card to set the gap.

[timber tramp]

I just use a business card to set the gap.

  Me too.
I would think a brass feeler guage would be just fine to use as well.    TT

[joe_indi]

I just use a business card to set the gap.

  Me too.
I would think a brass feeler guage would be just fine to use as well.    TT

So would I, if not a bit of that aluminum from a milk powder can.
But here the closer gap would get some juice out of that ignition module if it was working even a little bit.
It takes a lot to kill a Stihl saw module but there are exceptions.

Carl, I would also examine the HT lead for any missing insulation.
Is the connection end of the spark plug tight on the spring in the plug boot or is it only the boot which is holding it in place?

The module looks quite the same as that of a MS180(018/017).


You could pull the module out of a 18 or 17 and try for a spark.
If you do get a spark then the fault could be attributed and confirmed to the ignition module.
Try a screw driver on both ends of the magnets on the flywheel.Is any end showing up as being weaker?
Joe

[CarlMs280]

Thanks to all who posted.  It turned out to be the ignition module.  Swapped it out and it fired right up.

I used the business card to set the gap when I installed the new one.  Is that generally good for all small engines or only Stihl?

It was cool that I could fix it myself (with help from here) instead of just having the dealer fix it.   
(I like the dealer and they seem to have reasonable prices, but just it just seems better to do it myself)

Thanks,
Carl.

[Cut4fun]

I use the business card on my Huskys, Poulans, Redmax's, Stihl's, Solo's, Jonsered, Partner's, etc etc  ;).    smile_banjoman