McCulloch Chain Saws

[heimannm]

I can do a bit better than that Ed...

I have two different types, the wire screen with the flocking that you are familiar with, and another that is more like a thin felt, but limited quantities of each of course.

Mark

 

[j-jock]

Were resistor plugs around when the points saws were made?

I thought resistor plugs were something to do with radio interference and wondered what that had to do with chainsaws.

Resistor plugs were designed in the 40s, to cut down on radio interference. Back then, all ignition wire was solid metal. In later years, the manufacturers designed resistance wire, made from carbon impregnated cloth. The wire, was designed to have approximately the same resistance, approximately 5,000 ohms, as the resistor in the plug, and thus eliminating the need for the extra cost of building a special spark plug.
I was taught that the ignition resistance had virtually no effect on the operation of the ignition system.

You can calculate the voltage needed for electricity to jump across a spark gap with a simple formula: voltage equals the air gap length in centimeters times 30,000.
I don't have my calculator handy, but assuming the gap is .035 in:
0 .035 in x 2.54 cm/in x 30,000 = required voltage to fire the plug = 2,667 volts
I could not find any information regarding how much the resistance in the plug or the wire changes the voltage required to fire the plug.

Whether it is a point triggered standard ignition or an electronic ignition, would not change the voltage. The difference with an electronic ignition is, that the higher secondary voltage of the electronic ignition, reduces the total current draw in the system.
In automotive use 12v system..... normal draw equals approximately 2 amps.
electronic system, primary voltage 400 v, and current drain equals approx .1 amp
The lower amount of current in the electronic, CD, system, is why the plugs live longer.

 

[edju1958]

I can do a bit better than that Ed...

I have two different types, the wire screen with the flocking that you are familiar with, and another that is more like a thin felt, but limited quantities of each of course.

Mark

Why the crazy prices on the 600 series AF?I thought someone out there was making aftermarket AFs?Back about 4 or 5 yrs.ago I bought about 10 used AFs for something like $20.I'll be danged if I didn't use 'em all.

 

[Maintenance supervisor]

I put solid metal core wires in my 68' Plymouth Fury once and could hear what the aliens were saying about us through the 8-track player!

 

[Rotax Steve]

Speaking of electronic ignitions.....I put oil in the Timber Bear today & couldn't seem to get it to oil,so I fired it up.It ran for about 10 seconds,then died.I tried restarting it but it would only sputter.Had to tear the recoil/fan housing off again & replace the ignition module.Put it back together & it fired right up & now it runs & oils well.I noticed after cleaning the AF that the flocking is mostly gone.I looked on feebay & saw that the price on the AFs is outrageous.One seller has 2 for $188 & another has an AF for $121.What's up with those prices?

 

[Rotax Steve]

Speaking of electronic ignitions.....I put oil in the Timber Bear today & couldn't seem to get it to oil,so I fired it up.It ran for about 10 seconds,then died.I tried restarting it but it would only sputter.Had to tear the recoil/fan housing off again & replace the ignition module.Put it back together & it fired right up & now it runs & oils well.I noticed after cleaning the AF that the flocking is mostly gone.I looked on feebay & saw that the price on the AFs is outrageous.One seller has 2 for $188 & another has an AF for $121.What's up with those prices?

I see one's that show a "buy it now" price of $222.95 from Randy's Engine Repair but they must be typos and he accidentally hit the number 2 one too many times. I'm sure it's $22.95. Randy's Engine is good dependable parts. FeeBay must be all supply and demand because I've gotten them for $8 a piece before. You can even get them on Amazon.

 

[Ironhorsedoctor]

There was an interesting article a few years back that I hadn’t been able to find. It referred to pulse width and voltage feedback on
non resistor spark plugs and ignition module on chainsaw and other small engines. I did find these tho!

 

[Ironhorsedoctor]

I know that's how you "cleaned" them,I remember your post from last yr.The paper probably just wiped off any oil that may have accumulated.
Ira may be right in that he said you should probably convert the 81 over to an electronic chip.They're easy to do & will be more reliable.No "scary" points to worry about.I can buy the chips on Amazon or eBay for around $10-$15.There are 2 different types - a 1 wire (which I prefer) & a 2 wire

The electronic chip will bypass the OEM points and condenser and create a spark but the saw may not have the same performance and power do to the different ignition timing. Both systems create spark but they create it differently. If I’m not mistaken Stihl in their 028 series had an early and late model. The IPL shows two different ignition systems with two different flywheels. If the electronic chip works that’s great! If you encounter issues see if you can find a compatible flywheel or some how tweak the timing. Points rarely fail. They burn and pit and will need to be cleaned and readjusted. The main culprit is the condenser!

 

[Ironhorsedoctor]

I see one's that show a "buy it now" price of $222.95 from Randy's Engine Repair but they must be typos and he accidentally hit the number 2 one too many times. I'm sure it's $22.95. Randy's Engine is good dependable parts. FeeBay must be all supply and demand because I've gotten them for $8 a piece before. You can even get them on Amazon.

I don’t think it’s a typo! I’ve seen quite often on eBay. I shake my head and laugh and move on. Seller posts an outrageous price waiting for a fish to hook. All you need is an mis informed buyer and the seller has a great day! Sellers monitor their sale items. What do they have to lose! Absolutely nothing!

 

[edmxz2002]

Can anyone tell me what the resistance readings should be for a mac 1-76? I have a saw that has no spark. Here is a little background on what I have done. When I got the saw, I poured some mix into the carburetor, it started and ran for 20 or so seconds. I removed and cleaned the carburetor. Put the carburetor back on and now, no spark.

Someone put in a chip (before I got it). The points and condenser have been eliminated. I am trying to determine if the coil is good before I spend the $$ to try another chip.
I have checked the stop switch and wire. When disconnected from the coil, it is open circuit. When plugged back into the coil I get a direct connection to ground. Any advice on what to check is greatly appreciated.

TIA
Ed

 

[Maintenance supervisor]

The electronic chip will bypass the OEM points and condenser and create a spark but the saw may not have the same performance and power do to the different ignition timing. Both systems create spark but they create it differently. If I’m not mistaken Stihl in their 028 series had an early and late model. The IPL shows two different ignition systems with two different flywheels. If the electronic chip works that’s great! If you encounter issues see if you can find a compatible flywheel or some how tweak the timing. Points rarely fail. They burn and pit and will need to be cleaned and readjusted. The main culprit is the condenser!

I find and I think most do that chip conversion gives an older saw with points ignition a little more zip and better throttle response.
I've keep some points but I've converted enough to notice a difference that I'm gaining some performance.
Points will continue to function long after a service should have been done ,but always at the sacrifice of easy starts or sluggish rpms and misfiring.
Electric ignition is working or not , rarely you notice it breaking down before it fails. Always delivering the same performance.

 

[knightmax]

Sorry been absent...Been busy unbagging parts...

 

[Syncop8r]

Sorry been absent...

Should we excuse him fellas?

 

[bob kern]

Should we excuse him fellas?

Absolutely!

 

[edju1958]

I contacted Miss Joan,Bob J.'s lady-friend,& she says that he just spends the entire day in front of the tv.He has no interest in going out to the shop whatsoever.It's been exactly one yr.since he had his heart attack.I haven't talked with Bob since his birthday back in Feb.

 

[edju1958]

Silly me,I've been rambling on about the latest Timber Bear.I've been told that it doesn't exist unless there are pics.well here they are.

 

[knightmax]

I contacted Miss Joan,Bob J.'s lady-friend,& she says that he just spends the entire day in front of the tv.He has no interest in going out to the shop whatsoever.It's been exactly one yr.since he had his heart attack.I haven't talked with Bob since his birthday back in Feb.

She tells me the same. Bob has no desire to go to the shop at all.

 

[flatsfisher]

I don’t think it’s a typo! I’ve seen quite often on eBay. I shake my head and laugh and move on. Seller posts an outrageous price waiting for a fish to hook. All you need is an mis informed buyer and the seller has a great day! Sellers monitor their sale items. What do they have to lose! Absolutely nothing!

a lot of ebay vendors use a large sum as a placeholder so no one will order that item until they get more stock in.

 

[mbellot]

Hey Mark H. - Have you opened an Amazon shop? These look awfully familiar.

https://www.amazon.com/GardenPal-Compatible-McCulloch-Replaces-Replacement/dp/B09GFBWFYP

 

[Jethro 2t sniffer]

We have a lovely blue spark