McCulloch Chain Saws

[heimannm]

The seats can absolutely swell and restrict fuel flow, I have had that happen 2 or 3 times already.

Some HL carburetors have a high speed check valve, some do not. I'm not sure if the "do not" class use a sintered metal capillary seal like the MAC carburetors. In either case I think you need to pop the welch plugs out and see why fuel isn't flowing through the H circuit.

Looking at the IPL again, the HL63 does have a check valve, you may have to take extra measures to make sure it is clean and passing fuel.

Mark Heimann

 

[MacAttack]

Yes, that means that you're pumping and metering enough fuel. It must be something in the high speed circuit.

Thank you Mr Hansen!

Sounds like I need to pop the carb off and try cleaning out the Hi speed circuit....

 

[MacAttack]

The seats can absolutely swell and restrict fuel flow, I have had that happen 2 or 3 times already.

Some HL carburetors have a high speed check valve, some do not. I'm not sure if the "do not" class use a sintered metal capillary seal like the MAC carburetors. In either case I think you need to pop the welch plugs out and see why fuel isn't flowing through the H circuit.

Looking at the IPL again, the HL63 does have a check valve, you may have to take extra measures to make sure it is clean and passing fuel.

Mark Heimann

I'm thinking the same thing Mark... I'm not afraid of popping out Welch plugs but now I'm wondering about finding a new plug and check valve.....

 

[MacAttack]

I might have what I need but not sure what I'm looking at and whether I have a check valve or not....but I do have 2 welch plugs.

What is that TINY brass plug thing??

 

[Rallyeguy]

For all you 125 aficionado's I have finally made up reproduction stickers for the Super Pro 125, and 125C saws.

Should be the best reproduction available as far as looking correct.

https://www.oldsawshop.com/McCulloch-Super-Pro-125-Stickers-c178373878

I also am working on some 10 series early style stickers. Some are very accurate but the really early style I'm making are not embossed like the originals. These are run but need to be cut....Hopefully sometime this next week.

 

[vinnywv]

Those are really nice. Be proud of your work!

 

[MacAttack]

Well guys, I've got the 450 4-stroking real nice on WOT now. I can't say exactly what did it, but I sealed the fuel inlet gasket with Hylomar because it was weeping gas, and I also blew carb cleaner and compressed air through the Hi fuel circuit. It's running real nice now, sounds powerful.

My only remaining perceptable issue is a bit of fuel spray from the venturi into the airbox and pooling. I'm guessing the reeds aren't sealing quite tight. I'm just not motivated to tear the saw apart to try and remedy it, so if it's running good I'm going to just have fun with it, drain the pooled gas out and live with it.

 

[MacAttack]

Took the 450 out back for a few test cuts and I'm very happy, tons of power! What a beast this thing is.

Also, when I'm using the saw, it didn't seem to pool gas in the airbox, so that seems like a non-issue now.

 

[AWise_mac_nut]

Here is a video I've put together now that the second bp1 is together, showing the cosmetic differences between the January and October models of bp1s, what a learning experience this was for me

 

[Brufab]

BP-1 based plywood saw, I must find that Popular Science article that showed it.

The button on the handle releases the latch on the guard so it can swing out of the way.

Chain is scratcher type chain.

Operator holds the saw just like you would a BP-1 chainsaw.

View attachment 1249651

View attachment 1249652

Mark

The scratcher type chain is quite interesting

 

[Brufab]

I might have what I need but not sure what I'm looking at and whether I have a check valve or not....but I do have 2 welch plugs.

What is that TINY brass plug thing??

That basically looks like what I have used in tillotston hl,159a's

 

[AWise_mac_nut]

For the life of me I can't find a thin-walled 5/16" socket that I can use to remove the seat. I have 2 brand new seats in kits. But...my problem is not enough gas on the Hi adjustment, and the needle / seat hold pressure. I might try raising the metering lever about 20 thousandths and see if it helps.

I wonder if it's possible that the rubber seat is swelled up and restricting the flow of gas?

I use a klien screw driver minus the bit end it fits perfect with a nice handle on it and it handy as a designated carb rebuild tool

https://www.lowes.com/pd/Klein-Tools-11-in-1-All-Purpose-Multi-bit-Driver/5014351829

 

[Rallyeguy]

For all you 125 aficionado's I have finally made up reproduction stickers for the Super Pro 125, and 125C saws.

Should be the best reproduction available as far as looking correct.

https://www.oldsawshop.com/McCulloch-Super-Pro-125-Stickers-c178373878

I also am working on some 10 series early style stickers. Some are very accurate but the really early style I'm making are not embossed like the originals. These are run but need to be cut....Hopefully sometime this next week.

I finished cutting the 10 series stickers, and they are all available at https://www.oldsawshop.com/ Scroll down, all the new stuff is listed as featured product.

For all of my stickers and waterslide decals See: https://www.oldsawshop.com/McCulloch-Stihl-Poulan-&-Pioneer-Stickers-&-decals-c173211751

 

[Joe Crow]

Joe - it will run pretty rich on the high side, but you can really lean on it and it will still have plenty of fuel. I like my PM55 with the fixed H, it cuts very well.

For the L, you want crisp acceleration so adjust it to where you have the best throttle response, then adjust the idle speed to insure the chain stops at idle. Usually 1 to 1-1/2 turns out from lightly seated. If you are far off that range I'd say something is amiss.

Mark

Thanks Mark
This carb does not have a High adjustment. It has a one screw adjustment which I think is for the idle adjustment based on a users manual.
Joe

 

[Joe Crow]

When you say lean on it, do you mean lean on the cut?

 

[MacAttack]

Yep, he means to really load the saw in a cut.

 

[JSMississippi]

Cleaned it up yesterday after the dirty clearing work at the camp. Tested the auto oiler too, all good there!

Now that it seems to be all sorted out and running, gave it a cleaning and put the new stickers on. I doubt this one was an SE (most photos I see they had a black AF cover), but I have such a strong liking for the goose logo. Brian, if you ever decide to make the 10-10S SE stickers, I'd be in for a set!

 

[ThistleIA]

That cool. I took a similar photo a couple of years ago.

June 2013,the 125C still sees occasional use on the big stuff,the mini mac given to me by older brother (he bought it new in early 90's sometime),has a leak in the gas tank I never could fix so its on a shelf with my other parts donors.

 

[docholliday64]

I have a PM 805 that I picked up recently - very little wear, so I don't think it was used very much and then sat for a long time. The only thing I could find wrong with it was a rotted out fuel line.

I checked the compression and it seems low - 125 psi

The saw will start and run fine when cold, but once it warms up, it starts to act like it is lean and eventually dies.

I pulled the carburetor and it looks brand new inside, diaphragms and gaskets in good shape. The piston on the intake side looks really good too, have not pulled off the exhaust yet to look at the exhaust side.

I replaced the gas cap duck bill thinking that maybe the tank wasn't venting.

I'm thinking maybe an air leak? Stuck rings? Looking for any advice on where I should go next.

 

[Syncop8r]

Pressure and vacuum test.