McCulloch Mac 120 - Condenser replacement.
- Thread starter Noremac
- Start date
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This shows they have no points....
https://www.leonschainsawpartsandre...0_120_130_chainsaw_ipl_217019__sep._1983_.pdf
Maybe you have an earlier version of this?
https://www.leonschainsawpartsandre...0_120_130_chainsaw_ipl_217019__sep._1983_.pdf
Maybe you have an earlier version of this?
This is what the condenser looks like.
OK. Yeppers... I see some units DID use points.
https://www.mccullochchainsawguide.com/mcculloch-chainsaw-parts/mcculloch-100-series-160s/
Yikes.... pricey for new OEM!
https://www.ebay.com/itm/1261695312...PfRp8LSejkzGRUvAeCZW883A==|tkp:Bk9SR9C83pmuYw
https://www.mccullochchainsawguide.com/mcculloch-chainsaw-parts/mcculloch-100-series-160s/
Yikes.... pricey for new OEM!
https://www.ebay.com/itm/1261695312...PfRp8LSejkzGRUvAeCZW883A==|tkp:Bk9SR9C83pmuYw
McCulloch used the same condenser on many saws from the 1960's forward.
I would start by cleaning the points, I have found very few bad condensers.
Mark
I would start by cleaning the points, I have found very few bad condensers.
Mark
Funny thing, I cleaned the points. Managed to get spark again. When I put it all back together in it's casing, I lost spark and haven't been able to gain it back. It's gotta be the condenser right? Points gapped to .018 and flywheel/coil gapped to .013.
That is pricey. I could make my own for a few bucks, if I knew what capacitors to use...
Barrow or buy a digital DVOM. Digital Volt Ohm Meter and test the condenser. It's basically a capacitor. A meter with capacitance test would be better but not fully required.
From some general net sleuthing, the condenser should be around .18-.22 uF (micro farad) when using a meter with that function.
If you still strike out, you could convert the saw to electronic style with an ignition module.......
https://www.ebay.com/itm/1856718766...Kjzquo58A+Wvit0ITxXwr4NA==|tkp:Bk9SR66U6qiuYw
https://www.ebay.com/itm/3929929652...TbdWZPR0TMPM0c2sSAoKYC8H8=|tkp:Bk9SR66U6qiuYw
If you still strike out, you could convert the saw to electronic style with an ignition module.......
https://www.ebay.com/itm/1856718766...Kjzquo58A+Wvit0ITxXwr4NA==|tkp:Bk9SR66U6qiuYw
https://www.ebay.com/itm/3929929652...TbdWZPR0TMPM0c2sSAoKYC8H8=|tkp:Bk9SR66U6qiuYw
Thanks for your time Chevboy0167. Vintage Engine Repairs got me in the right direction. Your video did help me with the condenser and seems to be working fine.
Thank you Vintage Engine Repairs! Followed Chevboy0167 on the Condenser and it does seem to be working fine. Followed your video for the rest and found my secondary winding in the coil is not giving a reading. What could have caused the secondary winding to fry? I managed to get spark before I put it all back together.... Can you short out a coil?
Did you set your multimeter to resistance rather than continuity?
Yes. Got 1.5 on primary and no reading on secondary.
Interesting! No rust anywhere? Where you testing from? The spark plug boot / spring or the tiny barb on the coil pack once you have removed the HT lead?
meteoritedude
New Member
i had 2 mac's that had that symptom - spark on bench, then no spark when re-assembled into case. One, the problem turned out to be the kill switch. it was all bent out of shape. Eliminated it, put in a button instead. On the other one, the kill switch wire was being squeezed a bit when putting the case on. The wire ran thru a maze inside.
Often times the coil will test O.K. on the bench but not with the wire clipped on the saw due to the connector in the boot pulling away from the plug wire. Pull the boot off, clip about 3/16" off the end of the plug wire and replace the connector and the boot.
My bet is still on the points, you may need to clean them again.
Mark
My bet is still on the points, you may need to clean them again.
Mark
I had 1.5 when it was mounted to the engine. Now 2.1 on the primary. Still nothing on secondary. All points are clean and rust free.
Attachments
Do as Mark says about removing the boot. You can then get a good connection with your ohmmeter onto the HV lead for a good test of the coil secondary.
I agree with Mark, if you had spark and then lost spark you probably need points. When I see or suspect erratic points I pull the flywheel then disconnect the coil primary lead from the points and rotate the crankshaft and monitor the points making good contact with the Ohmmeter while I rotate the crankshaft. Old points are usually contary when disturbed and sometimes they just wont come around even with a good burnishing because they no longer have the good points mating surfaces.
Also if you suspect a condenser might be OPEN I've connected a test condenser to the kill switch wire and if the saw runs normal you then know that the condenser is bad without first having to pull the flywheel and monkey with the old one. I've even disconnected the old condenser if I suspect it's intermittently erratic and if I did not have the correct one for re-mounting under the flywheel I just install one at the coil or kill switch area. (it's electrically connected to the same place but not under the flywheel) I very rarely find a condenser bad but when one goes erratic it can really upset the ignition and engine performance. Most all ignition points condensers are the same value in UF of .18-.22. It's the physical mounting that is the hangup and some old condensers are like trying to buy a VINTAGE dinosaur egg, they are hard to find and then over priced because they have the part number you THINK YOU want. (people helping people)
I agree with Mark, if you had spark and then lost spark you probably need points. When I see or suspect erratic points I pull the flywheel then disconnect the coil primary lead from the points and rotate the crankshaft and monitor the points making good contact with the Ohmmeter while I rotate the crankshaft. Old points are usually contary when disturbed and sometimes they just wont come around even with a good burnishing because they no longer have the good points mating surfaces.
Also if you suspect a condenser might be OPEN I've connected a test condenser to the kill switch wire and if the saw runs normal you then know that the condenser is bad without first having to pull the flywheel and monkey with the old one. I've even disconnected the old condenser if I suspect it's intermittently erratic and if I did not have the correct one for re-mounting under the flywheel I just install one at the coil or kill switch area. (it's electrically connected to the same place but not under the flywheel) I very rarely find a condenser bad but when one goes erratic it can really upset the ignition and engine performance. Most all ignition points condensers are the same value in UF of .18-.22. It's the physical mounting that is the hangup and some old condensers are like trying to buy a VINTAGE dinosaur egg, they are hard to find and then over priced because they have the part number you THINK YOU want. (people helping people)
