McCulloch Chain Saws

[Dake]

I’m not sure what the two little medal loop are for on the bar bolt? Not sure if I need them thought it was a spacer. I can’t find it in the IPC.

 

[Squareground3691]

I’m not sure what the two little medal loop are for on the bar bolt? Not sure if I need them thought it was a spacer. I can’t find it in the IPC.

Bar slot spacers,

 

[Dake]

Thanks with the name I found this looks like I don't need them on the bar I'm using.
https://www.arboristsite.com/thread...ecoil-bar-selection-help.364682/#post-7935936

 

[heimannm]

Kubota - You probably need to start with a compression test (should be >100 PSI to run correctly) and also pressure test the crankcase to make sure there are no leaks. Beyond that, make sure you have a good, consistent spark, have a look at the fuel line in the tank as well as the fuel filter, and check the line between the tank and the carburetor to make sure it is sound.

If all of that checks out, time to disassemble the carburetor for a good cleaning and replace any gaskets or diaphragms that are questionable.

Sometimes, erratic operation on the front tank saws means the airbox is loose, and that requires a major disassembly to access the screws under the oil tank.

Regarding the choke, there should be a screw/knob sticking up from the choke button (13) and a spring pin on the bottom side (14) that allows you to latch the choke on but beware, sloppy mechanisms often do not hold the choke fully closed with the button latched down.



You may find it easier to start the saw laying on a log or a bench, hold the throttle open and choke closed with your right hand while pulling the starter rope with your left hand.

Mark

 

[Rotax Steve]

Not sure if this is the correct place to ask? But i'm trying to get a old 250 running correctly.
Will start and run with a little fuel down the carb bore and will stay running and while trying to adjust it will stall unless i half choke it. Will not accel at times and just runs funny, first seem very rich and then lean. Cleaned up the carb and replace fuel line.
And how should you use the choke if it is spring loaded, hard to hold choke on and pull cord!!
Strange that it work like that.

If you're not able to secure the choke you must be missing the stem that allows you to lock the choke in place. Push choke in and turn it to the left and it should hold it.
I once had the same problem you're having and found out my intake gasket seal was bad and would cause the fuel/air mixture to fluctuate. The saw seemed to have a mind of it's own and how it was running was not consistent at all. It would run good, then bad, good again then not at all...etc.

 

[KUBOTA OWNER]

Hey thanks for responding, I have replaced the fuel hose from the carb to the tank. Filter and pick up in tank are both clean and not plugged. Piston and cylinder look great looking through the exhaust. Did not take compression test, but it feels great. Cleaned points and set gap, has a great spark. Saw starts on first pull almost every time after putting a little fuel down the carb bore.
There is no way to lock the choke on, only a black place knob to push. It does seem to stay running if i hold choke half closed. Then seem to run rich, then to lean? screwy!!
---Does anyone know what carb. kit I should get? The carb is a Tilloson # HL63d
I will pressure test and check for any leaks? I have pressure tested husky saws before. Are these different with a reed plate? -- Plug off carb, and exhaust, pressure hose in spark plug hole, correct?
Love these big old saws! Thanks to all for any help. will keep you posted on outcome.

 

[altatim]

What would be the part replacement for a Super 250 clutch bearing and rim clutch drum? Looking to acquire these but I couldn't find any information on replacement parts other than a babbit bearing for the clutch (I would like a needle bearing conversion if possible). Thanks all

 

[Maintenance supervisor]

Hey thanks for responding, I have replaced the fuel hose from the carb to the tank. Filter and pick up in tank are both clean and not plugged. Piston and cylinder look great looking through the exhaust. Did not take compression test, but it feels great. Cleaned points and set gap, has a great spark. Saw starts on first pull almost every time after putting a little fuel down the carb bore.
There is no way to lock the choke on, only a black place knob to push. It does seem to stay running if i hold choke half closed. Then seem to run rich, then to lean? screwy!!
---Does anyone know what carb. kit I should get? The carb is a Tilloson # HL63d
I will pressure test and check for any leaks? I have pressure tested husky saws before. Are these different with a reed plate? -- Plug off carb, and exhaust, pressure hose in spark plug hole, correct?
Love these big old saws! Thanks to all for any help. will keep you posted on outcome.

Very simply cleaning the carburetor will not solve the fact that aged diaphragms inside the carburetor are hard and shrunken, instead of soft and supple.
The fuel flow depends on the diaphragms to pump and be flexible in order to maintain proper mixture.

 

[Squareground3691]

Hey thanks for responding, I have replaced the fuel hose from the carb to the tank. Filter and pick up in tank are both clean and not plugged. Piston and cylinder look great looking through the exhaust. Did not take compression test, but it feels great. Cleaned points and set gap, has a great spark. Saw starts on first pull almost every time after putting a little fuel down the carb bore.
There is no way to lock the choke on, only a black place knob to push. It does seem to stay running if i hold choke half closed. Then seem to run rich, then to lean? screwy!!
---Does anyone know what carb. kit I should get? The carb is a Tilloson # HL63d
I will pressure test and check for any leaks? I have pressure tested husky saws before. Are these different with a reed plate? -- Plug off carb, and exhaust, pressure hose in spark plug hole, correct?
Love these big old saws! Thanks to all for any help. will keep you posted on outcome.

https://www.ebay.com/itm/1917302589...lx6FfZ4S9a&var=&widget_ver=artemis&media=COPY

 

[heimannm]

Kubota - RK88 is the Tillotson HL full kit, DG5 is the gaskets & diaphragms only.

altatim - Your Super 250 should have a 9/16" diameter shaft and tapered clutch. You need to determine the bore of your drum, as there are two different clutch drum types and they use different bearings. I am not familiar with any 9/16" drum with a brass bushing, but many of the 5/8" bore drums used a brass bushing in place of a needle bearing.

86464 and 90359 are a large spline drums that use (different) needle bearings, there are other part numbers that include the sprocket; for example 90341 is the same 90359 drum with a 3/8-7 sprocket. 90359 has a smaller bore and uses a different bearing than 86464, I don't remember the different bearing numbers off the top of my head.

51774 is a 404-7 spur type drum with needle bearing

60917 has a 404-7 "fixed rim" type sprocket that is not replaceable and a needle bearing

65379 has a 7/16-7 spur type sprocket

If needed, I could try to put together a better list of the drums and bearings but this should get you started.

If you can't find the parts in Canada, I have a selection of drums and bearings available.

Mark

 

[KUBOTA OWNER]

Thanks so much, will pressure test and then pull the carb and replace the gaskets and diaphragms.
I do think its a carb issue. Will let you know how it comes out. Thanks

 

[Clayton A Clark]

In order of motor size I have a mac125 (123cc), model 73 (120cc gear drive), pm1000 (100cc), super44A (87cc), 1-53 (80cc), 250 (80cc), G-70 (72cc), pm610 (60cc) and an early 10-10A (50+cc). All of them get used in rotation then cleaned and displayed until the next go-round. The 73 is a beast with a long bar once you dig the spikes in and push. The 125 is a legend and deserves it. The pm 1000 cuts about like a 660 with a 32" bar on it (maybe a little more guts). the super 44A is heavy but suprisingly quick. The 1-53 and 250 cut about the same and share a bar. The 10-10 is one of the strongest saws in this size segment that I have ever used. Oh yeah..... I almost forgot about the little mini mac 6 top handle.

Do you have either a PM1000 parts saw or a recoil housing for one? I'm in need of a recoil housing for mine. If not, know where I can hunt one down?

 

[heimannm]

hoss has not been active for several years.

The PM1000 is a Partner P100, you might have better results checking in with that thread.

Mark

 

[edju1958]

The Titan 50/57 and DE50 saws use a Walbro HDA77 carburetor, and as an alternate the HDA46. The HDA77 seems to be in high demand, does anyone know if there are actual differences between the 46 and 77 or is it just perception?

Edit - I will add that the HDA46 has a 3/4" throttle bore, I don't have a 77 on hand to compare.

Mark

Mark,my DE80 has a Walbro SDC85 on it & it's stock as far as I know.

 

[heimannm]

The DE80 is a variant of the 82cc models, they will use an SDC or Zama C2 carburetor.

The Titan 50/57 and DE50 are "Italian McCulloch" saws with an entirely different set up.

I believe Mitch Weber made this photo.

Mark

 

[altatim]

Thanks for the information on the super250. What a well of knowledge you folks have!!

I will be hopefully getting into the clutch side today, I was just trying to find out what is what because these saws are new to me. Does 110 psi compression with an automotive tester sound o.k. on a Super 250? Kinda hard to pull it any faster than that but with such a long stroke I was hoping for higher comp. Rings aren't stuck and cylinder is very clean. Maybe just needs a new set of rings?

 

[altatim]

Also it’s a super 250 but only 1.375” stroke, making it an 80cc version. Is the porting still better than the 250 version of this saw? Here is the stamping.

 

[matt_lamb_160]

I have always treated 62481 as regular a 250.

This ad. shows all 6 transfer ports, all three exhaust ports and the third port are all drilled: https://www.ebay.com.au/itm/184487797241

 

[heimannm]

The 80cc Super 250 was built in Canada and featured the same all yellow color scheme as their US cousins. I don't know if the porting was better on those models, but the 250 could run pretty well. There were later model 250 saws released with a short, black AF cover that were thin ring models and they were also pretty good. I never bothered to check and see if the Canada Super 250 had thin rings or thick rings but it seems in every case the thin ring saws run better...at least for a while.



Mark

 

[serdie]

What would be the part replacement for a Super 250 clutch bearing and rim clutch drum? Looking to acquire these but I couldn't find any information on replacement parts other than a babbit bearing for the clutch (I would like a needle bearing conversion if possible). Thanks all

Contact Lil Red Barn and convert it to 3/8” while you’re at it