Mcculloch pro mac 10-10 wont start

[slimbo3006]

So I was given a free McCulloch pro mac 10-10. It looked pretty clean so I figured I would take a look at it even though I am not a fan of Mcculloch equipment. So far this one is reminding me why... So I checked the basics and just can not get this thing to fire. It will not even burp on fuel down the carb or starting fluid (yea I know)... So I verified that it has spark, both with a spark tester and grounding the plug. Compression is at 120 dry. Even pulled the flywheel to check the key. all fine...Set the coil gap to .010 on both magnets.. Spark plug gapped to .025.

What am I missing?? It has fuel/spark/compression it should fire...

I have already spent about 2 hours of my time on this..nearing what this thing is even worth if it is running.

This has been my experience with Mcculloch equipment...Everyone I have ever had just seems to refuse to start for some reason. Then one time it will just randomly start and run fine without changing a thing...But you had better no turn it off because there is no guarantee that it will start back up.

 

[Vintage Engine Repairs]

120 psi is in the range of not even being able to start so not that surprising. Put some oil in the cylinder to bump compression and then a squirt of fuel and see if you get anything.

 

[slimbo3006]

Hmm... didnt realize that they had that high of compression. I assumed 120 was average.

 

[thenne1713]

120 psi is in the range of not even being able to start so not that surprising. Put some oil in the cylinder to bump compression and then a squirt of fuel and see if you get anything.

but ALSO KILL SWITCH=off, PULL X3, THEN PULL SPARK PLUG AND SEE IF WET? and Yes, 120 is MIN to run on many? Was it leftover fuel, or YOUR FRESH mix fuel?

 

[slimbo3006]

So more subsequent compression tests are showing even lower readings down close to 110. Even when wet. looking through spark plug hole, the cylinder has some slight marks but nothing too bad. But I obviously can't see the piston and rings so who knows?
was trying it on my fresh mix. just putting it down the carb. Havent even gotten to whether or not the carb needs rebuilt or cleaned. figured I would make sure it would at least hit on some straight fuel first. Which it didnt.

Think I have pretty much spent all the time on this thing that it is worth. Would be different if it was something special.. May just try to salvage some parts off this thing and call it a day.

 

[thenne1713]

IF YOU CAN FIND A RING, (and I have seen some websites where you can order by dimensions?), you might be able to restore for $10-$15 (ring and base gasket?)... MIGHT be worth a little keyboard time?

 

[thenne1713]

INFLATION HAS TAKEN HOLD? BUT YOU MIGHT FIND ANOTHER SOURCE, CHEAPER? https://www.ebay.com/itm/1857096454...mr4404ewQr1JTXVHcdD2LE0os=|tkp:Bk9SR-6A5MTGYQ

 

[pdqdl]

Don't give up so quickly on that old saw. That is an antique, to be sure, but it is one of my favorite saws of all time. Mine ran for many years of commercial service without any problems.

You might be surprised what it might be worth to a collector. Sorry! I've already got one.

 

[Jasonrkba]

Saw was free. A $30 set of rings sounds like a good deal.

 

[Junk Saw Collector]

@slimbo3006 do you have any pictures of the saw? There’s plenty of people on this site that wouldn’t mind taking an old PM 10-10 off your hands.

 

[pdqdl]

Except for being heavy like a boat anchor, I'm not so sure that old 10-10 isn't just as good as any modern saw of comparable size. It's sure not as difficult to work on as the modern saws, but you do need to know how to tune it.

It seems to me that I ran mine as the only saw I owned from 1982 through 1987. We didn't quite do tree work full time, but not too far from it.

That's the saw I learned to cut trees down with. Same saw for climbing, too!

Yeah. I didn't know what I was doing back then. Still! The customer paid me when the job was done, nothing got broken, and we were turning a profit. I do remember real well how long it took me to cut up a 3' diameter tree with only a 20" bar.

 

[slimbo3006]

I have not even had a chance to look at it again. I had to prioritize a couple of bearings on my truck...

Here are a couple of pics of it. If anyone is interested in it, let me know. really doubt I will fool with it.
I did notice it is missing a muffler. can't really see a picture of the cylinder that well, but it doesn't look too bad. definitely seen runners that looked a lot worse

 

[j-jock]

I find it difficult to understand, that you were unable to start the 10-10. I have a couple of 10-10s, one of them being a Pro, and they were in terrible shape when I acquired them. Did you pull the plug, and dry it with compressed air before spraying the starting fluid? I have never had a saw with spark fail to start using starting fluid.
By lightly spraying some WD-40 and pulling the saw through a few times before removing and installing the dried spark plug. Then spraying a squirt of starting fluid down the carb, with the choke and throttle wide open, The saw will normally start in 10 pulls or less.
I have been using starting fluid on difficult 2 cycle engines for over 60 years, and have never damaged an engine by using this procedure.

 

[Jasonrkba]

Compression is to low to run. I'm not sure if the pro mac has a decomp but I'd check that. If not Take it apart and check the cylinder and piston. If they are good rering it and replace the seals. Check the bearings while its apart. The 10-10s are great saws for there displacement..... Or put it on the trading post section. Someone here wants it. What part of Virginia are you in?

 

[Tony Mayhew]

I find it difficult to understand, that you were unable to start the 10-10. I have a couple of 10-10s, one of them being a Pro, and they were in terrible shape when I acquired them. Did you pull the plug, and dry it with compressed air before spraying the starting fluid? I have never had a saw with spark fail to start using starting fluid.
By lightly spraying some WD-40 and pulling the saw through a few times before removing and installing the dried spark plug. Then spraying a squirt of starting fluid down the carb, with the choke and throttle wide open, The saw will normally start in 10 pulls or less.
I have been using starting fluid on difficult 2 cycle engines for over 60 years, and have never damaged an engine by using this procedure.

Agreed! I use Berryman carb & choke cleaner just one small squirt in plug hole and you can almost bet your last dollar it's going to light up! Even if just for a couple of seconds and then shutdown you can tell that you have compression and spark and you will know that you have a fuel delivery problem. And I always pull the cord four times maximum and if it doesn't fire up I go through a startup routine and figure out what is causing it not to start! I figure if it ain't gonna start after four pulls then it ain't gonna start if you were to pull it forty times. And nine times out of ten someone has already been there pulling until there eyes bug out and the saw is loaded with fuel in the crankcase.

 

[Jethro 2t sniffer]

I find it funny how Mac's take a dislike to certain people and then for ever after any Mac they touch already knows it and plays up

All the more yellow saws for us hehe

Same goes for victa lawn mowers

 

[Tony Mayhew]

I find it funny how Mac's take a dislike to certain people and then for ever after any Mac they touch already knows it and plays up

All the more yellow saws for us hehe

Same goes for victa lawn mowers

I have a few Macs in my collection of around 130 chainsaws! My favorite one is a 7-10 with no face cover on the exaust, Talk about disturbing the peace! And I don't know if it came stock with a high compression piston or someone gave that damn thing a shot in the shorts! But man will that thing ring your ears when it fires! And yes you are correct with that more yellow for us kind of thinking you got going on! and it too boggles my mind how many men think they got a chainsaw figured out but that's not the case my friend! Seems that they don't want to hear me when I loan my neighbor my Husqvarna L65 and I say, make sure you get some heat in the cylinder before you go WFO on the throttle! And he brings back my saw today and says, It won't start anymore! It ran for a couple of minutes and then it shut off and I couldn't get it to start again! And he did a cold seize on it and cracked the ring and luckily it didn't kill the cylinder! They seem to always have to learn the hard way enstead of just doing what you have told them not to do! I always ask them when try doing it their way, Don't you think maybe with as many chainsaws as I own that I might just know a little about how to operate one of these damn things?

 

[Jethro 2t sniffer]

I have a few Macs in my collection of around 130 chainsaws! My favorite one is a 7-10 with no face cover on the exaust, Talk about disturbing the peace! And I don't know if it came stock with a high compression piston or someone gave that damn thing a shot in the shorts! But man will that thing ring your ears when it fires! And yes you are correct with that more yellow for us kind of thinking you got going on! and it too boggles my mind how many men think they got a chainsaw figured out but that's not the case my friend! Seems that they don't want to hear me when I loan my neighbor my Husqvarna L65 and I say, make sure you get some heat in the cylinder before you go WFO on the throttle! And he brings back my saw today and says, It won't start anymore! It ran for a couple of minutes and then it shut off and I couldn't get it to start again! And he did a cold seize on it and cracked the ring and luckily it didn't kill the cylinder! They seem to always have to learn the hard way enstead of just doing what you have told them not to do! I always ask them when try doing it their way, Don't you think maybe with as many chainsaws as I own that I might just know a little about how to operate one of these damn things?

Poor old husky

 

[slimbo3006]

Yea so basically I got pissed off and tired of fooling with it. I just threw it in the shed for now. (was very tempted to just throw it away all together.) I will look at it again sometime when the weather is cooler. I hate working on these things in the summer.