MCCULLOCH The official McCulloch thread

[Sleeper]

Thanks guys for the info on the 610.

The other thing about the 610, is that it is easy to make it a PM650... the exhaust port has this casting flash on the sides... you will notice it right away if you take the bottom plate and muffler off... grind that out to the size of the rest of the port and it will wake it up quite a bit.

It would be slow, but they can pull a 28" bar. If you do that, keep the chain sharp and out of the dirt.

 

[Al Smith]

Keep in mind that thing is only 60 cc's although it weighs about as much as 125 cc saw . A 650 no matter what anyone says will not outgun a 610 .About all you can do to that saw is some work on the muffler .They aren't praticularly fond of a 28" bar .They do just fine with a 20" .

Besides all that it's a firewooder not a redwood slayer .With routine care that thing will last forever .

 

[Sleeper]

I stand corrected on the 610/650 deal. I've only ran the 610, but have seen the different port sizing between the two. I should've mentioned the 28" bar idea is only good in soft wood... I would not put that saw with that long of a bar into hard wood.

Got some work done on the saw today.

Will be going out to the barn again after supper.

Here is the saw when I started this afternoon...

See this crud in the cylinder? It probably got there by the last user of the saw... they had a wire screen for an air filter... no flocking left on it. Also, there is a hole in the center of the filter. I will get you a picture of that later tonight.

Bore looks like it could be honed and have a new set of rings slapped in... I will find out for sure after measuring the bore with a telescoping gauge and micrometer, and measuring the piston with a micrometer once the engine block is apart.

Hopefully, I remember how to use the micrometer.

First, that fuel tank assembly has to be removed, it's the last saw related part other than the bar oil tank.

Trying to find a place to pry the upper tank half away from the lower tank half... but it seems they did not put bosses anywhere for that idea... so I will have to find another way to separate the halves so I can get to the screws inside the tank. Might carefully scrape some gasket material out of the gap and get something thin in there.

 

[Stump Shot]

@Al Smith , You were spot on your prediction about the screws, ones in the cowling are gone that the starter mounts to causing it to malfunction. So guess it won't be a big deal to pop it apart and get at the muffler, with some of the screws already gone. Far as I've gotten with this saw as it has to work its way up the project list.

So I take it, from what you said I will need to find metric fasteners? Or were you referring to bore and stroke?

 

[Sleeper]

@Al Smith , You were spot on your prediction about the screws, ones in the cowling are gone that the starter mounts to causing it to malfunction. So guess it won't be a big deal to pop it apart and get at the muffler, with some of the screws already gone. Far as I've gotten with this saw as it has to work its way up the project list.

So I take it, from what you said I will need to find metric fasteners? Or were you referring to bore and stroke?

I have some parts for these saws... a few boxes actually. Let me know what you need. Small parts (bolts, screws, etc.) won't cost you a thing. (use an IPL part # and description of the parts your missing) If you don't have an IPL, let me know, I have most Macs on a disc, and can send you an email with the IPL. Or I can see what thread and length the various screws and bolts are and you can go to your hardware store and grab them.

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Back to my project... if that is okay with you.

Got the upper tank half off. Used my special custom ground screwdriver... it is very thin at the tip, with rounded corners to avoid gouging... used as gasket scraper and wedge for splitting tanks and stuff apart. Tapped on it with a small hammer, right in the gasket material between the screw bosses, and with a little working around the halves, it popped it apart.

Ran into something that is proving to be very hard to do... getting these three screws out, they hold the sawdust/chip deflector plate with the rubber flap to the saw. Seems like some numbnuts used loctite or something on these screws. I sprayed them with bolt buster a few days ago, and again tonight. Hopefully they budge. Never had this much trouble with these screws on two other saws. Those were tight, but not this stubborn.

If they don't budge, I think I will take the whole thing to a machine shop to have those screws removed without damaging anything.

My bench vise isn't big enough to hold this engine, and I don't have any slotted impact driver bits.

Here's the best pic for last... check out this "air filter" Yeah, it's real nice and will keep the big .404" chips out but let everything else in.

 

[Stump Shot]

I have some parts for these saws... a few boxes actually. Let me know what you need. Small parts (bolts, screws, etc.) won't cost you a thing. (use an IPL part # and description of the parts your missing) If you don't have an IPL, let me know, I have most Macs on a disc, and can send you an email with the IPL. Or I can see what thread and length the various screws and bolts are and you can go to your hardware store and grab them.

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Back to my project... if that is okay with you.

Thanks, I'll give ya a holler when I get at it.

...yes, it's OK with me. LOL

 

[Al Smith]

I have no idea what prompted McCulloch to come out with the 610 model .They already had saws of about the same displacement on the market .These things sold in the 225 range while at the same time. Stihl for example had the 042 which is tad larger for around 400 .I know they must have sold a million of them if you include the 650,and other variations of that model .

I have 3 at the moment,one my fathers saw was purchased for 169.95 at K-Mart .On the used market it's about a 75 dollar saw these days maybe less .All things considered it's a lot saw for the money if you think about it .

 

[Al Smith]

Need to mention some things about the 610 Mac .The most common failure is probably the oil pump .It's an impulse operated deal and it will oil any size bar that saw will pull .I've never had any luck trying to rebuild these pumps but have replaced several .

Second would be the coil .What happens is saw dust packs under the cylinder blocking the air flow .Sometimes once the coil cools off it will run again then some times it's done .So it's not a bad idea to occasionally blow the crude out .

 

[Sleeper]

Was going to order some shim stock for a thinner head gasket, but squish is probably good since the piston actually comes out of the top of the cylinder a tiny bit at TDC. Gasket is probably about as thin as it can be. I will check that later to see for sure.

I will be polishing the top of the piston, the cylinder head chamber, and the exhaust ports. Standard work to prevent carbon build up.

Got the three screws out... they had toothed lock washers on them... used my big old Craftsman flat head screwdriver with the square shaft... put a wrench on the shaft and got them to turn. Thinking about putting standard hex bolts on there... would be easier to deal with next time.

Wish I had a bead blast cabinet and big ultrasonic cleaner... (and room for both in the barn) would like to put everything in a kerosene bath in the cleaner and get all of the crud off, then bead blast the cylinder/block and head and top of the piston.

Got it down to the main engine assembly... minus cylinder head, stuffer, and intake.

Anyone have an extra oil tank? This tank has one spot where the bucking spike mounts to that is broken off... so there are only two holes for bolts to hold the spike... would like three. It is the top hole that is missing, there was a chunk broken off there a long time ago.

 

[Sleeper]

And one more question... does anyone know which aftermarket reeds fit these saws?

 

[heimannm]

I have a few of the 600 Series saws, there are so many others I choose to run before it turn to one of these. Somewhere in the mix is a 650 that had been equipped with a 48" by a tree service outfit; he noted it was slower than the 840 they had been using, but was much easier to handle. Worked well enough for them if you were patient.



Since that time I have added the Montgomery Wards version, as 3420 Silver Eagle, the PM5700, and the 690 cut off saw.







Mark

 

[heimannm]

Sleeper - customchainsawparts on e-bay has the fuel tank gasket for around $12.

Invest in one of those hammer operated impact wrenches, marvelous tools for those stubborn screws.

Mark

 

[joeymt33]

I have a few of the 600 Series saws, there are so many others I choose to run before it turn to one of these. Somewhere in the mix is a 650 that had been equipped with a 48" by a tree service outfit; he noted it was slower than the 840 they had been using, but was much easier to handle. Worked well enough for them if you were patient.

View attachment 41041

Since that time I have added the Montgomery Wards version, as 3420 Silver Eagle, the PM5700, and the 690 cut off saw.

View attachment 41042

View attachment 41043

View attachment 41044

Mark

Hey Mark, that silver eagle looks familiar....

 

[Al Smith]

I'm kind of the same way with the 610's I own.I have better saws to use so they just sit,shelf queens .One belongs to my son and it looks almost brand new.Had a bad coil .

 

[Sleeper]

Sleeper - customchainsawparts on e-bay has the fuel tank gasket for around $12.

Invest in one of those hammer operated impact wrenches, marvelous tools for those stubborn screws.

Mark

Have an impact driver (hammer operated like you say)... bought it when I was working in the auto repair business. Snap-On. Yes, I paid a lot for it, but at the time, I was making good money.

It came with some sockets, some torx bits, some allen bits, and some phillips bits. Just need to find some slotted bits for it, and buy a bigger bench vise that can hold these big block saws.

Thanks for the tip on the tank gasket... I will be happy to buy that rather than make it.

 

[Sleeper]

Measured the bore of the cylinder and it comes out to 2.128" at the top of the cylinder. Piston is about 2.125" Think honing it and a set of rings will work?

 

[T.Roller]

Big thank you @sawfun I received this super 250 today. Fired up on the second pull and sounds amazing. I also received a very nice old oregon .404 bar and .404 square ground chain. Best packaging job I've seen!

 

[Frank bierce]

Awesome!!! Good looking unit there!!

 

[sawfun]

I'm glad you like it. She's a great cutter.

 

[T.Roller]

Any thoughts on putting a header off a regular 250 on it? I have 2 lol