McCulloch Chain Saws

[Nogoingback]

I went through the same carb issue with mine. It is very sensitive to metering lever adjustments. Lower it a little and it should settle down.

As for rod float, I'm no help. I haven't experienced that yet...

Pulled the carb to check the lever height and thought it was flush but was just a hair high. Set it a little low and put it back together. Thanks for the info and hopefully soon I can find out if that fixes it.

 

[leeha]

I went through the same carb issue with mine. It is very sensitive to metering lever adjustments. Lower it a little and it should settle down.

As for rod float, I'm no help. I haven't experienced that yet...

Thats why i went a different route and used the largest race HL
out there. I didn't want the aggrivation of the flat back but here
i am with carb issues still at a year and a half later. But i did find
someone who is working with me and hopfully my build will be
done soon. This 125-101 has been the most aggrivating and time
consuming build i have ever done. But i wanted it a bit different
than the others.




Lee

 

[leeha]

Today I got to find out if my saw would run, and it did. The excitement was short lived though. First tried it with some gas down the carb and it fired off pretty quick. Next step was filling the fuel tank and seeing if it was going to leak and surprisingly it didn't. The tank was seriously hacked on and modified to clear the carb and intake. Choke plate was removed so a little gas down the carb was needed again and after a second or two it was running on it's own and pulling gas from the tank. This is one loud mo fo.

Now for the first of the problems and this one is minor compared to the second issue. First issue is after running a while it didn't want to restart after shutting it down and could only get one good pop each time turning it over. Inside of the carb throat looked very wet so after leaning the mixture screws didn't help any, it was time to take the carb apart and look for problems. Going to try lowering the inlet lever a little first. Got it on the bench, removed the plug which was very wet and while pulling the saw over slowly, i saw gas shooting from the brass tube in the carb throat. Would the metering lever too high cause this? It was set flush with the carb body.

Now comes the big problem. After i pulled the plug and turned it over to dry the cylinder out some, the engine would turn over hard in the same spot every time. I'm first thinking the crank is rubbing on the stuffer, but why would it if it didn't before. A lot of bad scenarios are going through my head right now so first thing to do is remove the oil tank and stuffer. With the stuffer removed and looking inside, i found no big chunks laying in the bottom and no rub marks on the stuffer. I feel a little better for now but I did find what was binding and it's the big end of the connecting rod. It will turn over a bunch of times and then the rod works it's way over to the flywheel side and binds up. Lay it on it's side flywheel down and it binds every time. Clutch side down, it doesn't bind. I thought another member had the same issue after rebuilding a 250 but i couldn't find that thread.View attachment 306423

Any and all help will be greatly appreciated.

Not sure why your rod bearings are binding. I've rebuilt several
of the 123cc Mac's and never seen it. There was a member here
that had the same issue. I can't remember what he did to solve
the issue.
I would double check the crank pin diameter, ID of rod and the
diameter of the needles. If memory serves the count should be
24 needles. Also make sure the rod cap is perfectly aligned with
the rod when you tighten the rod bolts. That style bolt i torque
to 90 inch lbs with oil on the threads not loctite.




Lee

 

[ozflea]

Not sure why your rod bearings are binding. I've rebuilt several
of the 123cc Mac's and never seen it. There was a member here
that had the same issue. I can't remember what he did to solve
the issue.
I would double check the crank pin diameter, ID of rod and the
diameter of the needles. If memory serves the count should be
24 needles. Also make sure the rod cap is perfectly aligned with
the rod when you tighten the rod bolts. That style bolt i torque
to 90 inch lbs with oil on the threads not loctite.




Lee

Make sure you have the big end cap on the right way around it only fits one way

McBob

 

[Warped5]

Maybe so............but they weigh a ton and sound like a mid-50s Buick farting into an oil drum.:msp_wink:

(Aaron, if you're gonna repeat me, please be accurate)

IMHO, they weigh and balance just fine ....

 

[heimannm]

When I took mine down, I only found 22 rollers at the crank/rod connection...I had a few bags of NOS bearings in a box and checked the dimensions very carefully against ones in the engine, and put in the new bearings. Should be 24 as Lee pointed out.

That was not the only issue I encountered going through the engine, worn bore with taper and out of round, piston that looked to be at least 0.020" undersized and scored, corrosion on the shrouds, you get the idea.

Mark

 

[Nogoingback]

Not sure why your rod bearings are binding. I've rebuilt several
of the 123cc Mac's and never seen it. There was a member here
that had the same issue. I can't remember what he did to solve
the issue.
I would double check the crank pin diameter, ID of rod and the
diameter of the needles. If memory serves the count should be
24 needles. Also make sure the rod cap is perfectly aligned with
the rod when you tighten the rod bolts. That style bolt i torque
to 90 inch lbs with oil on the threads not loctite.




Lee

Lee

Crank pin measured fine and the needles were the same as another new set I have. Didn't measure the rod yet but there was hardly any time on the engine when I got it. I'll pull it check if i can't find a solution soon. Putting the crank back together, I some grease to hold the needles in place and torqued down the cap like you said. Laid it on the flywheel side and spun it over a bunch and wouldn't bind at all even while pushing the rod to the side. Flushed the grease out with WD and brake clean so I could put some oil on the bearings and now it binds up right away while tipped on its side.

 

[Nogoingback]

When I took mine down, I only found 22 rollers at the crank/rod connection...I had a few bags of NOS bearings in a box and checked the dimensions very carefully against ones in the engine, and put in the new bearings. Should be 24 as Lee pointed out.

That was not the only issue I encountered going through the engine, worn bore with taper and out of round, piston that looked to be at least 0.020" undersized and scored, corrosion on the shrouds, you get the idea.

Mark

Mark

I did find a post in a karting forum that talked about guys running minus two or more needles for less friction. Maybe that was the deal with yours or they're laying on a floor under somebody's workbench.

Looking good for Baraboo so far?

 

[rwoods]

I have not figured my similar binding problem out yet as saw is still a part waiting for all new bearings. I have wondered if the crank bearings could be slightly tweaked. Ron

 

[Eccentric]

(Aaron, if you're gonna repeat me, please be accurate)

IMHO, they weigh and balance just fine ....

I've been making the oil drum comparison for years. The Buick thing is all yours, and I don't feel the need to repeat it....

 

[RandyMac]

I've been making the oil drum comparison for years. The I-H thing is all mine, and I do feel the need to repeat it....

:hmm3grin2orange:

 

[homelitejim]

Should I be able to feel the difference in power between the pm610 and pm650? Both wear a 20" bar with 70dl's of full comp chain.

 

[ethar]

Homelitejim Considering they are basically the same saw probably not. Only difference I noticed between the 610 I had and a friends 650 was weight. You also have to remember at that time there where 4 or 5 saws badged differently but where essentially all the same innards. On e-bay I've seen a few montgomery ward (Sears), TYM and a few others all the same saw.

PM 650
ENGINE DISPLACEMENT:
3.7 cu. in. (60 cc)
CYLINDER BORE:
1.85 in. (47 mm)
PISTON STROKE:
1.38 in. (35 mm)
CYLINDER TYPE:
Aluminum with chrome plated bore
INTAKE METHOD:
Piston ported

PM 610
ENGINE DISPLACEMENT:
3.7 cu. in. (60 cc)
CYLINDER BORE:
47 mm
PISTON STROKE:
35 mm
CYLINDER TYPE:
Aluminum with chrome plated bore
INTAKE METHOD:
Piston ported

 

[Nickolas]

10-10S fuel lines

I recently got a 10-10S and I am not familiar with this saw at all. It is the first 10-10 I have ever held in me hands. Anyway I got one of the many fuel lines off ebay to replace but it won't work. My housing has a metal bushing in it so the fat part of the hose won't fit in there. Is this how the saw is or has someone added this to the saw? The seller said he has never had any issues with the fuel lines I bought and has never heard of this metal bushing. So what am I suppose to do just go buy some fuel line to run through the hole and find a filter to work Or should I try to knock out that bushing and put this hose in?

Nick

 

[joeymt33]

I recently got a 10-10S and I am not familiar with this saw at all. It is the first 10-10 I have ever held in me hands. Anyway I got one of the many fuel lines off ebay to replace but it won't work. My housing has a metal bushing in it so the fat part of the hose won't fit in there. Is this how the saw is or has someone added this to the saw? The seller said he has never had any issues with the fuel lines I bought and has never heard of this metal bushing. So what am I suppose to do just go buy some fuel line to run through the hole and find a filter to work Or should I try to knock out that bushing and put this hose in?

Nick

You're lucky, that bushing was a upgrade kit sold by mcculloch. It could have been built into the saw originally or added later as they could have been bought over the counter. You can use standard fuel line with out having to worry about purchasing those fairly high 10- series fuel lined.

Just go to your local part house and find a line and filter to fit it.

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[joeymt33]

Should I be able to feel the difference in power between the pm610 and pm650? Both wear a 20" bar with 70dl's of full comp chain.

I can feel the difference in power in those two saws. The super 610, 650, 655 had a larger exhaust port and it does make a difference.

I'll find some pictures of that soon.




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[joeymt33]

Here are the pictures if the NOS 650 cylinder and a used 610 cylinder.

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[heimannm]

Among the saws and such I bought a year and a half ago (big Cad day for me) was a Pro Mac 650 that had been fit with a 48" bar. The tree outfit was using that saw rather than the 840 that had been fit with a 36" bar. Old Ben noted that the PM650 was not a strong through the big stuff as the 840 had been but it was a lot easier to handle.

By the time I got it, the 650 was pretty well used up.

Mark

 

[joeymt33]

Among the saws and such I bought a year and a half ago (big Cad day for me) was a Pro Mac 650 that had been fit with a 48" bar. The tree outfit was using that saw rather than the 840 that had been fit with a 36" bar. Old Ben noted that the PM650 was not a strong through the big stuff as the 840 had been but it was a lot easier to handle.

By the time I got it, the 650 was pretty well used up.

Mark

A 48" bar?!!!


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[heimannm]

It may have only been 42", I didn't measure it to know for sure but it certainly looked big on the saw.

Oh, by the time I got the saw the big bar was long gone...

Mark