Sachs Dolmar 110 no spark

[Howard Justice]

Used this Sachs Dolmar 110 saw couple years ago…. As usual a screamer! But it unfortunately was left in rain storm. Now no spark. Checked this week and still incredible compression …. But not star. Ordering new plug … but if that doesn’t fix it ….. do i then look at magneto? And are they even available for this saw I bought in 1989? BTW I do not significant experience repairing saws beyond the basics.
Thanks much!

 

[J D]

With your new plug check for spark before you screw it into the saw (remember it needs to be held against the cylinder). Next I would try disconnecting the kill switch to eliminate that.
Have you dumped the gas & put fresh mix in it?
Are you sure water hasn't made it into the crankcase?

 

[L34]

Is the flywheel magnets/coil poles rusty?

 

[Howard Justice]

With your new plug check for spark before you screw it into the saw (remember it needs to be held against the cylinder). Next I would try disconnecting the kill switch to eliminate that.
Have you dumped the gas & put fresh mix in it?
Are you sure water hasn't made it into the crankcase?

Thanks…. How would I know if water entered crankcase?

 

[Dogtracks]

Hello, new to this site and wondering if someone has some magic for my no spark problem.
I have a Dolmar ps7900 with no spark, I have replaced the Coil and still no spark, read on here about bad flywheels so I replaced the flywheel ( both OEM ) and still no spark, the kill switch is new and disconnected so it's not that.
I have 3 plugs 1 new, I have continuity from head to screws on coil, and I tried adjusting the gap between coil and FW magnets and no spark. The saw was giving me some problems last summer which I thought was the kill switch, the saw sat in an unheated garage all winter but that never seemed to be a problem. Any ideas as to what's going on with this saw would be appreciated as I'm lost at this point.

 

[J D]

Thanks…. How would I know if water entered crankcase?

Take plug out, turn it upside down & pull it over a bit.... Unless the cover & air cleaner were off or it was in a position for the exhaust to fill up with water it's unlikely that will be your problem

 

[J D]

Hello, new to this site and wondering if someone has some magic for my no spark problem.
I have a Dolmar ps7900 with no spark, I have replaced the Coil and still no spark, read on here about bad flywheels so I replaced the flywheel ( both OEM ) and still no spark, the kill switch is new and disconnected so it's not that.
I have 3 plugs 1 new, I have continuity from head to screws on coil, and I tried adjusting the gap between coil and FW magnets and no spark. The saw was giving me some problems last summer which I thought was the kill switch, the saw sat in an unheated garage all winter but that never seemed to be a problem. Any ideas as to what's going on with this saw would be appreciated as I'm lost at this point.

Welcome aboard, you will likely get a better response by starting a new thread of your own.
In the mean time, what did you set the coil gap to, did you disconnect the kill switch at the coil (to eliminate the wires as well), are you using your original ht lead, is the coil new OEM or at least known to be good?

 

[Howard Justice]

I will do that. I mistakenly must have opened in some else’s thread…. I’ll go back to working on it this weekend when have new plug. Grateful for your guidance.

 

[J D]

I will do that. I mistakenly must have opened in some else’s thread…. I’ll go back to working on it this weekend when have new plug. Grateful for your guidance.

This is your thread, I was referring to Dogtracks asking about his 7900 with similar issues

 

[Howard Justice]

Ok. Thot so….. are you a Sachs Dolmar fan?

 

[Dogtracks]

Welcome aboard, you will likely get a better response by starting a new thread of your own.
In the mean time, what did you set the coil gap to, did you disconnect the kill switch at the coil (to eliminate the wires as well), are you using your original ht lead, is the coil new OEM or at least known to be good?

Thanks for reply, I set gap to 3mm and tried a wider too, yes disconnected kill wire at the coil, brand new coil (red) has exact numbers as original OEM and OEM flywheel.
I'll try starting a new thread...

 

[L34]

Coil gap should be about 10tho.
3mm seems far to wide.
Use a business card to do gap.

 

[Dogtracks]

Thanks for reply, I set gap to 3mm and tried a wider too, yes disconnected kill wire at the coil, brand new coil (red) has exact numbers as original OEM and OEM flywheel.
I'll try starting a new thread...

Sorry it's 0.3 mm, first I used a business card and that didn't seem to work so used something thinner, I don't think it's a gap issue

 

[Dogtracks]

Well here's something, I put a ground wire to the plug and grounded to the screws on the coil, I turned the flywheel with a cordless drill and at fast rpm and I see a spark. It doesn't spark at low rpm, and the spark is not very bright when it does spark. I took the ground wire off and held the plug on the head, spun the flywheel with the drill and had spark at high rpm, but not very bright spark, I don't think I can pull this thing over fast enough to generate a spark.

 

[J D]

Ok. Thot so….. are you a Sachs Dolmar fan?

I have a couple & I like em. A 110i was one of my first saws actually... but these days I have considerably more Husky's in the shed

 

[J D]

Well here's something, I put a ground wire to the plug and grounded to the screws on the coil, I turned the flywheel with a cordless drill and at fast rpm and I see a spark. It doesn't spark at low rpm, and the spark is not very bright when it does spark. I took the ground wire off and held the plug on the head, spun the flywheel with the drill and had spark at high rpm, but not very bright spark, I don't think I can pull this thing over fast enough to generate a spark.

What plug are you using & what is the gap set at?

 

[leaf]

Ignition coils in chainsaws do go bad. I relatively recently repaced a coil on a Stihl 034 and on a Husky 455. Both went from nada to starting and running well with new coil. Carefully measure resistance on primary side (spark plug wire to ground - anything close to zero or over a few killo-ohms is suspect) and secondary side (kill switch tab to ground - zero or anything over a few hundred ohms is suspect). Suspect only means suspect. Best to compare with a known good coil. Intrernal electronics of coil modules vary, you may be "looking" at a capacitor or semiconductor. Generally speaking, flywheel magnets don't go bad unless flywheel gets assaulted. But coil modules have their failure rate...

 

[Dogtracks]

What plug are you using & what is the gap set at?

I've been using NGK BPMR7A and since have no spark tried Champion, gap 0.5 mm

 

[Dogtracks]

Ignition coils in chainsaws do go bad. I relatively recently repaced a coil on a Stihl 034 and on a Husky 455. Both went from nada to starting and running well with new coil. Carefully measure resistance on primary side (spark plug wire to ground - anything close to zero or over a few killo-ohms is suspect) and secondary side (kill switch tab to ground - zero or anything over a few hundred ohms is suspect). Suspect only means suspect. Best to compare with a known good coil. Intrernal electronics of coil modules vary, you may be "looking" at a capacitor or semiconductor. Generally speaking, flywheel magnets don't go bad unless flywheel gets assaulted. But coil modules have their failure rate...

Thanks, I'll check the resistance when I get back home, fishing this weekend... I did play with the flywheel to see if it had any damage, it would draw a hanging screwdriver from about an inch+, I didn't think it was bad but replaced it because nothing else was working

I've been using NGK BPMR7A and since have no spark tried Champion, gap 0.5 mm

I was thinking I should try a hotter plug ?

 

[J D]

I was thinking I should try a hotter plug ?

Plug temp will make no difference if there's no spark... & you have the correct spark plug.
Did you replace the HT lead with the coil?