McCulloch Chain Saws

[Rallyeguy]

Oh! I get what you're saying now! Boy do I feel stupid. I've been rebuilding HDB carbs a lot lately which only have a flat tab and haven't rebuilt an SDC in a couple years. I forgot the forks on each end have a purpose. It was not attached - will that solve things?

That will definitely have an affect on fuel supply. In your case a non seating needle that floods the saw. No reason to feel stupid, we're here to learn.....

 

[Rallyeguy]

Based on what I'm seeing, your forked end is level with the outside edge of the body and needs to be level with the inside floor of the casting (see circle for refrence). Yours looks way too tall. When assembled the fork also has to connect inside the diaphragm (slide on) where the metal meets the fork.

The lever acts as a seesaw at the axle. if the fork end is up too high or if the diaphragm catch isn't engaged and sits on top of that lever it presses it down so far the needle lifts on the other end of the seesaw, and cannot return to seat leaving an open fuel circuit which just dumps fuel into your intake.

It is also very easy to mix the order of gaskets up which can affect the way it runs. check the Carb IPL diagram to be sure everything is ordered correctly. I know a lot of very capable small engine guys that mix them up....just had one guy I sold a carb kit doing this yesterday, finally got it straight with him. His saw idled great until you tipped it forward then died....had a swapped gasket on the wrong side of the diaphragm. One simple thing that set the diaphragm in a slightly different location and it gave him grief. Fixed now but the can be a pain to figure out.

If you still have questions keep em coming, I know there are others with much broader knowledge than mine in here.

Brian

 

[Rotax Steve]

The spring is in the fuel line to keep it from developing a kink that would pinch the fuel line closed. Try to reinsert it into the area where the sharp bend occurs.

Once you assemble the carburetor correctly, pressure test it at the fuel inlet to confirm that it holds pressure.

Mark

Unfortunately I don't have a tool to do that with I'll just put it back together and see if I can get it running again. Saw was running great and I had two extra SDC carbs that I'd rebuilt (I've fixed the diaphragm on the other one too) and I was testing them on the 10-10 I have that I know works. The carb that was originally on it when it was running good I still have as well. Thank you for all your help. I'm sure if I pick up the 81E tomorrow you'll hear from me again

 

[Syncop8r]

I missed what sort of carb that is but Walbro and Zama make gauges to aid in setting the metering lever height for whichever model of theirs it is.

 

[JSMississippi]

Spent a few hours tearing it down further and deep cleaning all the large parts (cylinder, clutch cover/brake, FW cover, shroud, handle, bar, fuel tank, top, AF cover) last night. I’m not sure how dirty your saw finds have been, but this thing was filthy. Tons of oily sawdust caked everywhere! Still have a little bit more to go on the cylinder and oil tank. Still need to drop the auto oil pump. Want to clean up my bench before I split the halves.


Fuel tank bottom is nice and clean now. Inside of the top half is in great shape with what paint is there (old fuel was thankfully only in the bottom), so I’m going to leave it alone.
Are these aluminum or magnesium? I’ve seen mention of mag rot on the older saws, but did McCulloch switch metals on the later ones like the Pro Macs, or is it just less prevalent since they’re younger?


On another note, I sure am glad I heeded some past advice on here about keeping the flywheel nut on the crank when using a balancer puller. That thing would’ve nearly gone into orbit when it let loose!

 

[Maintenance supervisor]

Unfortunately I don't have a tool to do that with I'll just put it back together and see if I can get it running again. Saw was running great and I had two extra SDC carbs that I'd rebuilt (I've fixed the diaphragm on the other one too) and I was testing them on the 10-10 I have that I know works. The carb that was originally on it when it was running good I still have as well. Thank you for all your help. I'm sure if I pick up the 81E tomorrow you'll hear from me again

Hold the back of the lever down with your finger and use a tiny flat head screw driver to push the fork at the needle down , that will bend the lever. Adjust it correctly if needed by lifting under the back of the lever until it's level with the 2 posts , it is way out of spec and will not run without flooding.

 

[vinnywv]

Spent a few hours tearing it down further and deep cleaning all the large parts (cylinder, clutch cover/brake, FW cover, shroud, handle, bar, fuel tank, top, AF cover) last night. I’m not sure how dirty your saw finds have been, but this thing was filthy. Tons of oily sawdust caked everywhere! Still have a little bit more to go on the cylinder and oil tank. Still need to drop the auto oil pump. Want to clean up my bench before I split the halves.
View attachment 1237088

Fuel tank bottom is nice and clean now. Inside of the top half is in great shape with what paint is there (old fuel was thankfully only in the bottom), so I’m going to leave it alone.View attachment 1237089
Are these aluminum or magnesium? I’ve seen mention of mag rot on the older saws, but did McCulloch switch metals on the later ones like the Pro Macs, or is it just less prevalent since they’re younger?


On another note, I sure am glad I heeded some past advice on here about keeping the flywheel nut on the crank when using a balancer puller. That thing would’ve nearly gone into orbit when it let loose!

Yes they are generally disgusting dirty. Ive actually taken an entire assembled engine and threw it in a bucket of cleaner to help before. Didnt hurt a thing. Just was overly sure i got all the fluids out of the engine cylinder prior to any sort of attempt to start. Lots of air and guessing. Worked fine.

It looks like youre there now. 8 screws and a tap and itll be apart.

 

[Rotax Steve]

I got it! The SP81E. It's really dirty. Compression seems good. I forgot to push the decomp and almost tore my hand off. The cylinder looks good, decomp works, chain still has life and it runs! Started fairly easy. The only concern I have is that the gas tank cover is using some sort of sealant. Does anyone recognize what it may be? Looking forward to cleaning it up.
Also, I talked him down to $120

 

[Rotax Steve]

Here's some photos and a video.

 

[Jay Hansen]

Here's some photos and a video.

That one looks quite a bit above average if you ask me. Everyone liked those saws and generally used them up completely.

 

[Woodslasher]

THAT is the coolest saw I have EVER SEEN! Where can I get one???

I got it off a dude that bought it for $10 at a yard sale and was gonna use it as a post for his mailbox. I saw it on a shelf outside his barn, asked if he'd sell it and the rest is history.

 

[Jethro 2t sniffer]

Here's some photos and a video.

You are what is commonly referred to as a "tin ass" or also a "jammy c#*t" Well done . 120

 

[vinnywv]

Very nice. The sealant is factory sealant for the tank halves. Its a hard almost plastic feeling sealant.

 

[Macman125]

I've got two 81's, one in considerably better condition than the other, with a brake. Need to show them some love after I get my 262 and 200t out of the way. The clean one only needs some crank seals and possibly the carb gone through. The uglier one has a broken keyway for the flywheel. Haven't made up my mind whether I want to hunt down a crank or just part it.