Sachs Dolmar 112 Won't run

[droback]

New poster here but really impressed with the knowledge so here goes.

I have a SD 112 I purchased new in 1989. Ran good all these years until now. It's been on the bench for a few months and am just getting back to it.

Saw will turn over and run for a bit - pretty rough coughing and spitting. I can rev just a bit and then it cuts out (coughing and spitting all the way).

Lots of blue smoke and muffler has built up a thin coating of oil from this.

Carb has been rebuilt with standard HK rebuild kit including regulating needle.

Any help appreciated...

 

[Danno]

Start with the easy stuff. What's the scoop on the fuel lines?

 

[pioneerguy600]

Points and condenser ignition or electronic?

 

[sachsmo]

Check your compression,

I had a few of these that felt good, but they won't run under 110PSI.

New rings are cheap if the cylinder is not too bad.

Check out this guy for rings. Super to deal with.

Chainsaw Parts

 

[droback]

points or electronic

Points and condenser ignition or electronic?

Hey pioneerguy - good question, haven't taken that apart yet - it's all original...

But, manual indicates points as do most of the postings I've read here - (except one that said after a certain year they started to use electronic on the 112's ???)

 

[droback]

Points and condenser ignition or electronic?

BTW - spark seems strong and is blue

 

[sachsmo]

You basically need three things.
Spark
Fuel
Compression

If you have all three of these, it will run (as long as the spark is at the right time)

The only way the spark can be off is if the key sheared.

I would check compression first, rings are consumable, and can stick in the lands.

 

[droback]

You basically need three things.
Spark
Fuel
Compression

If you have all three of these, it will run (as long as the spark is at the right time)

The only way the spark can be off is if the key sheared.

I would check compression first, rings are consumable, and can stick in the lands.

Thanks sachsmo

Will check compression and fuel lines tonight.

The "spark at the right time" may be an concern - especially if has points...

 

[Danno]

If you've never touched the fuel lines, then my money is on those. About due for some, I'd say given it's age.

'course, my 028 has NEVER had new few lines and seems to be just fine, so I could be way off base on this.

 

[pioneerguy600]

BTW - spark seems strong and is blue

I asked that question because I have fixed more than 30 of the 112`s that had a common problem with the wire that connects the points to the coil. That wire will fail inside the insulation jacket, you can`t see it but the wire corrodes off inside the jacket, the engine will run at idle most times but it becomes very erratic at higher RPM. The wire will usually fail very close to the coil, only way to find the break is to pull on the wire with a moderate amount of force and it will streatch if the metal wire has failed inside the jacket.

 

[Nardoo]

I had similar woes with my early 112 so took Jerry's advice and checked the ignition. He was right, so an easy fix was to ditch the old points and condensor and replace the coil with an electronic one from the same series of saw (I used one from a 120Si). Really easy upgrade and my little 112 goes better than ever.

Al.

 

[pioneerguy600]

The 114143 500 electronic module is a direct swap in, done dozens of these swaps and it does away with those problematic coil wires.

 

[jeeptj19992001]

did you leave fuel in it, bet it is also due for a car overhaul

 

[whelenfan]

I had similar woes with my early 112 so took Jerry's advice and checked the ignition. He was right, so an easy fix was to ditch the old points and condensor and replace the coil with an electronic one from the same series of saw (I used one from a 120Si). Really easy upgrade and my little 112 goes better than ever.

Al.

Very nice looking saw!

 

[tomdcoker]

[Lots of blue smoke and muffler has built up a thin coating of oil from this.

Is this build up oil or carbon. If it is oil then it sounds like it is running to rich.

If the saw is orange in color it probably has points, possibably electronics. If it is black and white it should be electonic. Tom

 

[droback]

Ok.

Fuel line is new from tank to carb and line in tank looks good.

Compression tests out to just over 125PSI.

The saw is all orange (not the silver model) purchased in 1989. Any way to know for sure if points or electronic without pulling flywheel? Did any orange models of this era come w/electronic?

Did some searching for the P/N 114143 500 suggested - but no luck so far.

 

[droback]

Hmm, my last couple post attempts seemed to have gone no where so one more time

Fuel line from tank to carb is new and line in tank looks ok.

Compression tested out at 125PSI.

Saw is all orange (not the silver one) and purchased new in 1989. Any way to tell if points or electronic without taking off flywheel? Did any of the all orange 112's from that era have electronic ign?

No luck yet on finding 114143 500 electronic module P/N

 

[sachsmo]

Replacement ignition module for Dolmar

 

[sachsmo]

Compression testers can be all over the place.
125 is not ideal, but should run (150+ is what i would look for).
Have you pulled the muffler to look at the piston?
(you can email me a pic and I will post it)

Pioneer Guy has a lot of experience with saws so His advice is where I would start.
Even if your piston/cylinder is not scored, I would put a new ring in just because it's time. (and it's cheap and easy)

 

[droback]

Compression testers can be all over the place.
125 is not ideal, but should run (150+ is what i would look for).
Have you pulled the muffler to look at the piston?
(you can email me a pic and I will post it)

Pioneer Guy has a lot of experience with saws so His advice is where I would start.
Even if your piston/cylinder is not scored, I would put a new ring in just because it's time. (and it's cheap and easy)

Yeah I was wondering on the compression as my 032AV and Husky 257 both have better than 150psi. I did pull the muffler and I'm not a real expert but piston looks reasonable good (a couple small scratches) and the ring seems to be in the slot tight and is shiny silver. I'll try to send a pic tonight.

So - start with the top end or the electronics or maybe just do both.

Thanks sachsmo