BR600 NO SPARK

[pecon16]

I am Stumped (no pun intended) I am working on a family members very abused older BR600.  I cannot get spark.  I have all of the wires disconnected, spark plug out and spin the engine with a drill so I don't have to keep removing the recoil starter.  Due to the condition of the poor thing, I purchased an online  cheap coil.  First, it does not fit properly - and as seen in other postings, one of the screw holes needs to be enlarged...  that one is going back...  so I purchased a sealed new in box Stihl coil....  still no spark.  I have tried several different gap settings...  starting at 010 as the specs say (BS OEM coils come with a gap setting card - but your other ideas are great)...  still nothing.  Since I am only testing for spark, I am not concerned at this time about timing.  Magnets are fine... very strong pull on both magnets....  cranking clockwise from the flywheel end...

Any thoughts appreciated..  I would love to be blown away with the answer to this one.  OH My....

thanks

[ZeroJunk]

I assume you are grounding the plug to the cylinder some way.

[pecon16]

Oh yes --  I have used a copper wire to the head and even grabbed the wire...  nothing...  that is what is boggling me...  I wish I had a known good coil to try...  

[ZeroJunk]

Well, you could have gotten a bad coil. Would be odd to get two bad ones, but possible. Where are you in N.C. ? I have two or three that I "think" are good.

[pecon16]

Midland   South of Concord.

[thedoublejranch]

Is this an electronic ignition system or an old points system?

I had an old Sachs Dolmar that ignition failed. Module toast, no longer available (was made by Bosch) so I ended up installing one of these:

Amazon.com: ELECTRONIC TRANSISTORIZED IGNITION MODULE NOVA II: Garden & Outdoor

and it has been running fine since.

This can be used to convert a points system to electronic too. I converted an old outboard motor from the 50's into electronic ignition too.

[sawguy21]

It was built long after p&c were discontinued. I remember ignition problems with the 4-mix backpacks but can't recall what the solution was.

[joe_indi]

I have had my pack of woes with the 4 mix ignition, mostly on their brushcutters.
At times even the new replacement coil are faulty. There are too many things in that coil. An ignition advance, a speed limiter and God knows what else. If the speed limiter is faulty it will earth the current even when the flywheel is turned over.
As a test coil I keep the original version ignition coil of a Oleomac GS720(black not grey).
I get a spark with this coil, always.
So, a working test coil of sorts is a must. It eliminates the guess work.
But I dont know if a saw coil or a brushcutter coil that sits in the front would spark. They both have anti clockwise rotation of the flywheel while as the BR flywheel rotates clockwise.

[Ben Cut-wright]

Is this an electronic ignition system or an old points system?

I had an old Sachs Dolmar that ignition failed. Module toast, no longer available (was made by Bosch) so I ended up installing one of these:

Amazon.com: ELECTRONIC TRANSISTORIZED IGNITION MODULE NOVA II: Garden & Outdoor

and it has been running fine since.

This can be used to convert a points system to electronic too. I converted an old outboard motor from the 50's into electronic ignition too.

The NOVA you linked states "does not work with most Stihl".   NOVA is meant to eliminate mechanical contact breakers, points.    

[thedoublejranch]

The NOVA you linked states "does not work with most Stihl".   NOVA is meant to eliminate mechanical contact breakers, points.    

I installed it on a 1984 Sachs Dolmar with a Bosch solid state ignition system that failed and it works perfect. Same exact system used on Stihl too.
It certainly is worth a try for $13. Worked in my case.

[Hilltop366]

I'm thinking that the Nova would replace the trigger portion of the ignition, the trigger was used to replace the points and condenser but soon after the trigger was integrated with the coil like it is today.

[Ben Cut-wright]

The NOVA you linked states "does not work with most Stihl".   NOVA is meant to eliminate mechanical contact breakers, points.    

I installed it on a 1984 Sachs Dolmar with a Bosch solid state ignition system that failed and it works perfect. Same exact system used on Stihl too.
It certainly is worth a try for $13. Worked in my case.

The original component the NOVA replaced on the Sachs Dolmar you referenced were both similar devices, but neither are complete "solid state ignition systems".  Certainly not doubting the NOVA worked in that application.  The OP in this thread has an engine which does have coil and electronics encapsulated in a single component.  If by some happenstance the NOVA did somehow trigger spark in the Stihl, there is no assurance timing would be anywhere near correct. And, no convenient method of adjusting timing, as was the case with your Sachs Dolmar.

[ZeroJunk]

Yeah. That is a current production 4Mix blower. It is a single sealed unit with advance or retard depending on how you look at it for easy starting. Sometimes they will not take throttle and you will think it is a carb issue, but it is the coil not advancing with the RPM.

But still, no fire at all with two different units is odd.

[thedoublejranch]

he original component the NOVA replaced on the Sachs Dolmar you referenced were both similar devices, but neither are complete "solid state ignition systems".  Certainly not doubting the NOVA worked in that application.  The OP in this thread has an engine which does have coil and electronics encapsulated in a single component.  If by some happenstance the NOVA did somehow trigger spark in the Stihl, there is no assurance timing would be anywhere near correct. And, no convenient method of adjusting timing, as was the case with your Sachs Dolmar.

You are correct, this Sachs I was working on did have a separate control module outside of the coil. It was triggered by the coil and I did have to move timing and did have some movement/adjustment on the plate (slotted). I just did a websearch and found a guy who already did all the leg work and figured timing etc, I just came it after all the hard R&D was done. ;D
Thanks for the info too. :P