MCCULLOCH The official McCulloch thread

[edju1958]

I finished up on my latest PM 10-10 today.I went to take the old fuel line off the carb & it broke in half just by putting a pliers on it.I guess that's why it had fuel in the air box.I tried one of those ProLine fuel lines & filter & it seemed to fit snugly in through the tank.The saw fired right up after installation.
Then I tore the original recoil apart again & had to shine up the spindle with emery cloth & run a file across the pulley to remove the corrosion.Of course the recoil spring had to come flying out,just as well as it needed cleaning too.I got it back together & it works great now.

 

[Scott Kelsey]

Hoping someone here will help me out as I did some searching, but can not find what I am looking for.

I recently purchased this Pro Mac 850 and fired it up today. It will not fire with the choke on, but will start is i squeeze the throttle a few times. Also, what would be "stock" settings for the carburetor? It is a Zama twin jet carburetor. Thank you in advance for any help.

 

[Scott Kelsey]

 

[edju1958]

Seems to me you got it running ok Scott?

 

[edju1958]

I've got a PM55 that had an accident back in April.The saw fell off a shelf & broke the rear handle off.I swapped out the tank handle back in June & found that it needed a crank seal.The saw sat till today & I put a new crank seal in it,but found that the keyway on the crank is wallowed out.I put it back together in hopes that it'd fire up again,but not sure if the timing is off,or if it even has spark.I'll look into it more tomorrow,but at this point I'm gonna assume that the crank needs to be replaced.I saw a used crank on feebay that is supposed to fit many different models (pm 55,10-10,700,etc.).I have no idea if the crank swaps out for that many models.Any input is welcome.

 

[heimannm]

Scott, I would normally start with 1-1/14 turns open on both H &L. The fact that it starts with throttle and no choke would indicate flooding to me. I would go through the carburetor and make sure everything is correct (holds pressure, metering lever setting, etc., and you may need to test the HS check valve if it floods out at idle.

Mark

 

[heimannm]

Ed - your PM55 has points ignition, make sure any crankshaft you get has the points cam/lobe. All of the 54, 57, 60, and 71cc 10 Series models have the same 1.375" stroke but there are a number of differences in shaft lengths, keyways, RH/LH threads on the PTO side, and the aforementioned cam/lobe.

If you can't find one elsewhere, I should have a good used crankshaft available that will fit the PM55.

Mark

 

[edju1958]

Mark,according to the IPLs I have,the PM10-10 & the PM55 take the same crankshaft,part # 87699 for both.I've got a 10-10 short block sitting around,but I don't know what it came out of.I'll have to look in the a.m.I did find a partial short block from a PM 10-10 on feebay for $13 + shipping.I'll have to check with the seller to see if it has a points cam.

 

[edju1958]

I didn't find the short block for the 10-10 today,but I have a couple other places to look.The crank on feebay (according to the seller) is keyed at both ends,so that one won't work.I think this saw will be a winter project,if I even decide to do it).

 

[Rallyeguy]

I didn't find the short block for the 10-10 today,but I have a couple other places to look.The crank on feebay (according to the seller) is keyed at both ends,so that one won't work.I think this saw will be a winter project,if I even decide to do it).

These are all over ebay and lots of guys have them as the cranks didn't go bad on these saws. Best thing is to find a used one with decent bearings.

Did a search on ebay and this one would work with your saw. I looked it up and its a a left hand start with points. said he was running it so guessing bearings are good I'd replaced seals in case that was the cause.

McCulloch Pro Mac 10-10 M0D600014U Crank Shaft with piston | eBay

Find many great new & used options and get the best deals for McCulloch Pro Mac 10-10 M0D600014U Crank Shaft with piston at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Scott Kelsey]

Wondering what you guys can tell me about this 797 carburetor. I believe it is a Mcculloch flatback? From old threads I have read parts are almost non existent and they are hard to tune. Can anyone tell me why?

Also, what are the issues that the primers have? Just wear out with use and time? Thank you in advance for any help.

 

[heimannm]

Scott - I don't know if I tried to put together a similar thread here on OPE Forum, but there is a pretty complete thread on the Walbro/ MAC McCulloch flatback carburetors (including rebuilding the primers) on AS https://www.arboristsite.com/threads/mcculloch-carburetors.122113/

The MAC carburetors are a bit different from the cube type on more modern saws, but I find saws with the flatback actually perform best. Adjustments can be a bit more sensitive, but they do seem to work well on the saws they were intended for.

Kits are readily available these days, and for someone not inclined to rebuild the primer themselves, I have some rebuilt units available.

Brian Genrich (Old Saw Shop) and Jeff Fox (Cinci5) both have the gasket & diaphragm kits available, Jeff had his on sale last month (eBay) https://www.ebay.com/itm/1565372273...XFM01K&hash=item2472588881:g:0BEAAOSwOFNnbbtg

Mark

 

[Scott Kelsey]

Scott - I don't know if I tried to put together a similar thread here on OPE Forum, but there is a pretty complete thread on the Walbro/ MAC McCulloch flatback carburetors (including rebuilding the primers) on AS https://www.arboristsite.com/threads/mcculloch-carburetors.122113/

The MAC carburetors are a bit different from the cube type on more modern saws, but I find saws with the flatback actually perform best. Adjustments can be a bit more sensitive, but they do seem to work well on the saws they were intended for.

Kits are readily available these days, and for someone not inclined to rebuild the primer themselves, I have some rebuilt units available.

Brian Genrich (Old Saw Shop) and Jeff Fox (Cinci5) both have the gasket & diaphragm kits available, Jeff had his on sale last month (eBay) https://www.ebay.com/itm/1565372273...XFM01K&hash=item2472588881:g:0BEAAOSwOFNnbbtg

Mark

Mark, thank you very much. This is extremely helpful. I will read your link this evening.

 

[edju1958]

These are all over ebay and lots of guys have them as the cranks didn't go bad on these saws. Best thing is to find a used one with decent bearings.

Did a search on ebay and this one would work with your saw. I looked it up and its a a left hand start with points. said he was running it so guessing bearings are good I'd replaced seals in case that was the cause.

McCulloch Pro Mac 10-10 M0D600014U Crank Shaft with piston | eBay

Find many great new & used options and get the best deals for McCulloch Pro Mac 10-10 M0D600014U Crank Shaft with piston at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I took a look at this crank & piston,& the piston is pretty well shot - it's got some deep scoring to it.You might say "change the piston",easier said than done with me.My vise is broken,so I can't press the wrist pins out & in.

 

[Rallyeguy]

I took a look at this crank & piston,& the piston is pretty well shot - it's got some deep scoring to it.You might say "change the piston",easier said than done with me.My vise is broken,so I can't press the wrist pins out & in.

Hi Ed,

I wouldn't do a piston swap either...

I would remove 2 rod bolts and needle bearings and swap the rod and piston from your saw onto the new replacement crank. No press needed.

It's listed with free returns so if it comes in and the bearings are bad or the rod blue from overheating on the crank side its a free return.

Looking forward to seeing your resolution...

Brian

 

[edju1958]

Hi Ed,

I wouldn't do a piston swap either...

I would remove 2 rod bolts and needle bearings and swap the rod and piston from your saw onto the new replacement crank. No press needed.

It's listed with free returns so if it comes in and the bearings are bad or the rod blue from overheating on the crank side its a free return.

Looking forward to seeing your resolution...

Brian

I contacted the seller & he said there's no blue to the conn rod,the keyway slot looks good,& the bearings have "normal slop".I'm not afraid to change the bearings if need be,I have a bearing puller & have used it to pull bearings on a 600 series saw.The thing I worry about is changing the conn rod fropm my saw to this one.I've never done a swap like that & all I can envision is the needle bearings all over the place.My vision is not good.I may do it in an aluminum roasting pan to save any needles that may fall out.I did end up buying the crankshaft.Thanks Brian!

 

[Max the Mac Man]

I contacted the seller & he said there's no blue to the conn rod,the keyway slot looks good,& the bearings have "normal slop".I'm not afraid to change the bearings if need be,I have a bearing puller & have used it to pull bearings on a 600 series saw.The thing I worry about is changing the conn rod fropm my saw to this one.I've never done a swap like that & all I can envision is the needle bearings all over the place.My vision is not good.I may do it in an aluminum roasting pan to save any needles that may fall out.I did end up buying the crankshaft.Thanks Brian!

If you swap the rods by removing the rod bolts and swapping them from the old crank to the newer one keep in mind two things. A) the rods are cold broken when manufactured. The rods caps are mated to one particular rod. Make sure you keep them matched and mated. B) use the same needle bearings with the same rod. Torque spec on rod both is 65-70 inch pounds wet.

 

[Rallyeguy]

If you swap the rods by removing the rod bolts and swapping them from the old crank to the newer one keep in mind two things. A) the rods are cold broken when manufactured. The rods caps are mated to one particular rod. Make sure you keep them matched and mated. B) use the same needle bearings with the same rod. Torque spec on rod both is 65-70 inch pounds wet.

What He^^^^^^^ Said!!!

 

[cinci5]

I contacted the seller & he said there's no blue to the conn rod,the keyway slot looks good,& the bearings have "normal slop".I'm not afraid to change the bearings if need be,I have a bearing puller & have used it to pull bearings on a 600 series saw.The thing I worry about is changing the conn rod fropm my saw to this one.I've never done a swap like that & all I can envision is the needle bearings all over the place.My vision is not good.I may do it in an aluminum roasting pan to save any needles that may fall out.I did end up buying the crankshaft.Thanks Brian!

Ed if it doesn't work out I think I have one. Let me know.