McCulloch Chain Saws

[heimannm]

I had the 73 running today, discovered a crack in the gearcase cover I hadn't noticed before...oil was seeping through. Still having some issues with the carburetor as well, it will run up to full speed but doesn't like to idle consistently. I tried two different carburetors and the second one was better but not as dependable as my 77. I will have to look in the garage attic, may be another 4-30 or 47 up there with a carburetor I could try.



I cleaned the cover very thoroughly and applied JB Weld to the inside to seal it up. I've had great success with JB Weld in similar situations.

I was reminded when the saw was running that many older saws do not have any cover over the "cheese grater" dust guards...and the guard as two less fins than it did when I started. I was able to find the screwdriver...eventually...out in the grass...after it bounced off my head.

Mark

 

[Jethro 2t sniffer]

Speed of cranking over a points saw doesn't produce a hotter spark.In fact if you pull the plug out & ground it to the saw you should be able to produce spark while turning the FW by hand.The electronic ignitions require a brisk pull to get a good spark though.
On your SP81,your condenser could be getting weak,but usually it'll start breaking down when your saw gets warm/hot.If it's running at a high idle it could be crank seals.

Na no high idle it runs mint. Just a weak ish spark. Misses and wants to die if left to idle on first start for a few seconds. Goes good with a fresh plug but soon goes back to its grumpy starting.

 

[edju1958]

Na no high idle it runs mint. Just a weak ish spark. Misses and wants to die if left to idle on first start for a few seconds. Goes good with a fresh plug but soon goes back to its grumpy starting.

I'd start with giving the points a good cleaning.If that doesn't work then it may be time to put a chip in it,unless you have a stash of condensers.I'd have to go with dirty points though because running a strip of paper through them isn't a proper way to clean them..

 

[edju1958]

I got the newest Timber Bear on Tues.& I went through it fairly well.It was quite dirty & probably hasn't ran in 20 yrs.or more.I ended up pulling the carb & rerbuilding it,put it back on,but couldn't get it to idle for nothing.I had the idle screw turned in all the way & I fiddled with the needle settings to no avail.I put a brand new Zama on it today & the saw runs great now.The Walbro carb is apparently trash.After all that ,I put the bar & chain on it & couldn't get the oiler to work.I put kerosene in the tank thinking & hoping that the oil pick up was clogged with old sludge/oil.After playing with the oiler for several minutes I drained the tank & tipped it upside down & behold,the oil line & pick up fell out.Now I must tear the entire saw down to replace the oil line.As someone here put it a few yrs.ago,Mac took an oil line & built a saw around it.

 

[Jethro 2t sniffer]

I'd start with giving the points a good cleaning.If that doesn't work then it may be time to put a chip in it,unless you have a stash of condensers.I'd have to go with dirty points though because running a strip of paper through them isn't a proper way to clean them..

That's how I cleaned them hahaha . It did help though

 

[Syncop8r]

 

[Maintenance supervisor]

Na no high idle it runs mint. Just a weak ish spark. Misses and wants to die if left to idle on first start for a few seconds. Goes good with a fresh plug but soon goes back to its grumpy starting.

Jetho, most of my vehicles were points growing up. Changing them out every year was just part of the maintenance. Given the opportunity I always opt for electric ignition! Its just a consistent preforming system, easier starts and rpm. Hell I just converted my 68' Plymouth to HEI ignition .

 

[heimannm]

Repairs to the gearcase cover complete, back together and running again. Still weeps a little from around the starter cover even with two gaskets.

I guess after 67 years a little leakage now and then is to be expected...





Mark

 

[edju1958]

That's how I cleaned them hahaha . It did help though

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

 

[Syncop8r]

SES in Invercargill have them $35/40 NZD.



https://sesdirect.co.nz/collections/chainsawparts?q=ignition+module

 

[Jethro 2t sniffer]

Thank you guys

 

[JohnL]

I like points ignitions on small engines. Hotter spark at low rpm, most of these old saws aren't being used enough that they will wear out anytime soon, learn to set the gap and don't worry about it. Would only convert to a Chinese module if points kit is NLA.

 

[edju1958]

I like points ignitions on small engines. Hotter spark at low rpm, most of these old saws aren't being used enough that they will wear out anytime soon, learn to set the gap and don't worry about it. Would only convert to a Chinese module if points kit is NLA.

There are plenty of points still out there & the ones that are in the saws yet are usually still good,but they aren't worth a hill of beans without a good condenser.Condensers are scarce as hen's teeth & getting to be too expensive as well.Also,a condenser can go bad from just sitting on a shelf.NOS means nothing.

 

[edju1958]

I pulled the Timber Bear down today & replaced the oil line.It took some time as ya have to almost completely dismantle the entire saw.After taking the muffler off I found the gasket to be disintegrating,luckily I had one on hand that I got 2 orders ago from Mark.I didn't have any silicone sealant on hand so I used MotoSeal.I'll wait till tomorrow to put oil in,I'm waiting for the MotoSeal to cure overnight.I'll need to hunt up a couple of heat insulators & screws that go into the back plate,they're gone.

 

[Ironhorsedoctor]

Na no high idle it runs mint. Just a weak ish spark. Misses and wants to die if left to idle on first start for a few seconds. Goes good with a fresh plug but soon goes back to its grumpy starting.

Are you using a resistor plug or non resistor plug? Non resistor plugs for point and condenser ignition systems and resistor plug for CDI ignition systems. For those interested! A non resistor plug combined with a CDI ignition will ultimately fry the coil. A resistor plug with points and condenser tends to deliver a weak spark.

 

[Jethro 2t sniffer]

Are you using a resistor plug or non resistor plug? Non resistor plugs for point and condenser ignition systems and resistor plug for CDI ignition systems. For those interested! A non resistor plug combined with a CDI ignition will ultimately fry the coil. A resistor plug with points and condenser tends to deliver a weak spark.

I'll have a check n see. Interesting

 

[heimannm]

It is interesting that the 600 Series owners manual calls out the AC non-resistor plug (CS42T) and/or the Champion resistor plug (RDJ6).

The owners manuals for the 80's vintage saws with electronic ignitions call out for non resistor plugs, for example the PM850 and PM 850 Super call out 63432 which is the AC CS42T or alternate Champion DJ8J. There are a few calling for 93017 which, as best I can determine, is the Champion RDJ6 again.

The latest spark plugs I have by part number (301149) intended for the 32/35/38 cc model McCulloch saws are DJ7Y and those are all some of the last editions of electronic ignitions produced by McCulloch.

I have several saws with electronic ignitions running on the non-resistor Champion plugs and so far never an issue.

What is the theory behind the resistor type plugs being used in the saws with electronic ignitions?

Always learning...

Mark

 

[Syncop8r]

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.

 

[edju1958]

I was always told that ya need to use a non-resistor plug on a chainsaw.Like Mark,I run non-resistor plugs in my electronic ignition saws & don't have any issues.

 

[edju1958]

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?