MCCULLOCH The official McCulloch thread

[heimannm]

I actually have a corner of my display area dedicated to the 33/35/39 model saws. You can't see it in this photo but there is a Super 33 with the brush cutter attachment handing from the ceiling. The 35A was added after this photo was taken.



Mark

 

[Squareground3691]

I actually have a corner of my display area dedicated to the 33/35/39 model saws. You can't see it in this photo but there is a Super 33 with the brush cutter attachment handing from the ceiling. The 35A was added after this photo was taken.

View attachment 361185

Mark

I’ll take that Mcculloch jacket if it’s a XL . Lol

 

[edju1958]

The heat range is the least of your worries and a moot point sense the plug dynamics are no longer any where close to what it left the factory as. Plus, it's a chainsaw, Not a formula 1 car. Lol!

I beg to differ Steve.A plug that's too hot can potentially burn a hole in the piston.A plug that's too cold won't get nor keep the engine running.In essence,we need the Goldilocks plug.One heat range up or down won't matter too much,but beyond that one could be flirting with disaster.

 

[Steve]

I beg to differ Steve.A plug that's too hot can potentially burn a hole in the piston.A plug that's too cold won't get nor keep the engine running.In essence,we need the Goldilocks plug.One heat range up or down won't matter too much,but beyond that one could be flirting with disaster.

I seriously doubt you would be able to melt the large electrodes on an 18mm plug in a 57cc chainsaw running stock timing at 6-7:1 compression ration on 87 octane. But, I'm going to plead the @Al Smith rule on this one. "It's your saw, do what you think is best."

 

[jacob j.]

View attachment 361162 View attachment 361161

Excellent work - that turned out nice.

 

[Bmcnue]

I beg to differ Steve.A plug that's too hot can potentially burn a hole in the piston.A plug that's too cold won't get nor keep the engine running.In essence,we need the Goldilocks plug.One heat range up or down won't matter too much,but beyond that one could be flirting with disaster.

An 18mm plug won’t work, at least based off of what you’ve said so far. You mentioned the inserts you got that are the same as the ones suggested from McMaster-Carr just fall through the hole. The inserts from McMaster require either a 3/4 or 18mm tap to install which is the same or bigger than the 18mm plug. If the insert falls through so will the 18mm spark plug. Now if you were mistaken and didn’t have the same insert, then you could go with that insert and still stick with an OEM plug with no worries of melting a hole in your piston

 

[Al Smith]

About the only way you could burn a hole in a piston is running extremely lean .The plug itself won't do it nor will voltage firing it .If you find a burned off electrode and you know how to "read " a plug it will always be too lean of fuel mixture . As such most likely you'd hang a piston before it ever poked a hole in it. Saying that again do what you think is best .

 

[Stevemb]

I actually have a corner of my display area dedicated to the 33/35/39 model saws. You can't see it in this photo but there is a Super 33 with the brush cutter attachment handing from the ceiling. The 35A was added after this photo was taken.

View attachment 361185

Mark

that’s awesome! I’d definitely like to do another 33 with a different attachment.
I really like the look of the D44 too, so looking for one of those right now. Thanks for the kind words, I’m a beginner at this just kinda tinkering..so far

 

[Al Smith]

Here's an example going back over 50 years ago .My bud Jerry had the fastest '57 Chevy I ever saw .It had a hopped up ,cammed up 327 running 4 dueces .These were not Stombeg model 97 carbs .Stromberg /Bendix 500 CFM monsters with butterflies the size of a Campbells soup can. Just to keep it running he had to lean it out .Ran like a scalded ape but not for long .Burned holes in 3 out of 8 pistons in one night .Out to find another engine over that deal

 

[edju1958]

We had a Case combine on the farm that had a 4 cylinder Ford engine on it.I was out combining oats & it just quit on me.We had a friend come over & we pulled the engine apart to find that a hole had burned through one of the pistons.All the plugs were the same as I recall & the engine was never run lean.Maybe it was just a fluke?

 

[edju1958]

I finally got that pesky PM 5700 running! I put a new fuel line in it & a different carb.The original carb has something wrong with it that I can't figure out.I had to turn the lo screw out 2 full turns for it to throttle up without stuttering,then it wouldn't idle because it was set too rich.On top of that the hi needle wouldn't stay in,it kept falling out even with the spring on.Once I swapped out the carb it fired rioght up & idles nicely,throttles up well too.Here are some pics (just a rebadged Timber Bear or PM 605).I don't think this saw has ever seen wood,the interior was clean as a whistle,no sawdust anywhere.

 

[Al Smith]

Only once I saw this on a GMC 366 big block V8 truck engine .It scorched one piston .What caused it was a leaky spark plug which was repaired by an insert .The plug might have been loose and rattled around wobbling out the hole .What the damage was done by that one cylinder running lean .In theory when it came up on compression it blowed most of the charge out past the plug leaving it lean .How they found it was it finally blowed the plug out .That truck my bud had with a 60 foot boom cost him a bloody fortune to keep running .He saved the boom and scrapped the truck finally after it sat at my shop for about 2 years .

 

[edju1958]

An 18mm plug won’t work, at least based off of what you’ve said so far. You mentioned the inserts you got that are the same as the ones suggested from McMaster-Carr just fall through the hole. The inserts from McMaster require either a 3/4 or 18mm tap to install which is the same or bigger than the 18mm plug. If the insert falls through so will the 18mm spark plug. Now if you were mistaken and didn’t have the same insert, then you could go with that insert and still stick with an OEM plug with no worries of melting a hole in your piston

I didn't say I had the same inserts as those on McMaster-Carr,I said I had the same inserts as those suggested at Advance Auto - the Save-A-Thread Inserts.

 

[Stevemb]

The Super 33 is a good looking saw to begin with, you have done a really nice job of applying the special touch here and there.

You are correct, 1/2" pitch Pin Tail chain is very hard to find, in fact most any 1/2" pitch chain is becoming quite scarce.

I have a 35A that my brother picked up NIB, nice display unit.

View attachment 361184

Mark

That 35 is incredible! I was actually worried about the “special touches” I realize purists can take offense to such things, I plan on doing many more and will take liberties on those as well. I’ve been running saws for 20+ years.. climbing, boom truck all of it, just not “professionally “.and I make my living turning a wrench. but not on saws, i’m a rank amateur in this genre and not ashamed to admit it! Im looking forward to learning.

 

[edju1958]

I think I might've figured out what the problem is with the carb that was on the PM 5700.I was sitting at the table with 3 different carbs this a.m.(2 HDCs & the HDB).One of the HDC carbs had a leak down that I couldn't figure out till I took it apart & found that the metering diaphragm's metal nub was too long.Damn those cheap China kits! The HDB was another story.If you'll recall,I had to have the lo needle turned out 2 full turns in order for it to run without bogging when I'd throttle it up.It also ran so rich that it wouldn't idle even with the idle screw turned in all the way.The hi needle would fall out from vibration of the saw running.What would happen if some Bozo switched the needles?Would I be getting those results?BTW,I'm not that Bozo,I didn't pull the needles out of the carb till today.I won't find out if my theory is correct till I put that carb on a build that I'll be working on in the next couple months.

 

[MedicineMan]

I just finished rebuilding and beautifying my best running SP125. Had to prime her down the carb and hold the throttle wide open to get her started but when she fired she ran like a scalded cat. Could not get her to idle at all, though. After hours of troubleshooting, rebuilding carbs. swapping carbs, plugs, fuel lines and everything else I could think of I gave up. After lunch decided to take a nap on a cold rainy day.
Awoke with an epiphany. Can you guess what it was?

 

[jacob j.]

I just finished rebuilding and beautifying my best running SP125. Had to prime her down the carb and hold the throttle wide open to get her started but when she fired she ran like a scalded cat. Could not get her to idle at all, though. After hours of troubleshooting, rebuilding carbs. swapping carbs, plugs, fuel lines and everything else I could think of I gave up. After lunch decided to take a nap on a cold rainy day.
View attachment 362311 Awoke with an epiphany. Can you guess what it was?

Throttle rod was bound up on something? Sometimes also they'll act that way if someone has goobered the high idle screw on the throttle trigger.

 

[Squareground3691]

I just finished rebuilding and beautifying my best running SP125. Had to prime her down the carb and hold the throttle wide open to get her started but when she fired she ran like a scalded cat. Could not get her to idle at all, though. After hours of troubleshooting, rebuilding carbs. swapping carbs, plugs, fuel lines and everything else I could think of I gave up. After lunch decided to take a nap on a cold rainy day.
View attachment 362311 Awoke with an epiphany. Can you guess what it was?

Pinched line ? Hard to tell

 

[MedicineMan]

Tough place to take a photo, especially for someone who already struggles with cell phones and computers. Can you see what the throttle rod is resting against in the photo?

 

[Dream]

Tough place to take a photo, especially for someone who already struggles with cell phones and computers. Can you see what the throttle rod is resting against in the photo?

I can't, but then I'm blind as a bat also.
Seems like a good day to tinker with a large frame Mac.
I'm chasing a spark issue on this one.