McCulloch Chain Saws

[MacAttack]

Was anyone able to see this video?

I couldn't open it myself...

 

[super44]

I couldn't open it myself...

Thanks for the reply! I will try another way.

 

[heimannm]

 

[heimannm]

I put the 797 to work today, test log had to go with Phase 2 of the museum project moving along.



Mark

 

[MacAttack]

Started taking apart the McCulloch carb... unchartered waters. It's thankfully not very dirty inside, just old stale gas and oil residue.
Wasn't there a thread about working on these flatback carbs?

Edit: I found the link to Mark's Mac carb thread. Time to get reading....

 

[super44]

Thanks for the reply! I will try another way.

Try this

https://photobucket.com/share/ff1fc4c1-ff07-45da-bf45-453856aed36e

 

[MacAttack]

Try this

https://photobucket.com/share/ff1fc4c1-ff07-45da-bf45-453856aed36e

I was able to watch the video, I see what you mean about the revving at the end of the video.

How long has it been since a carb rebuild? I wonder if your fuel pump diaphragm could be getting a little tired and leaning it out? Or metering diaphragm getting stiff.

You'll probably get plenty of advice to have a pressure test done on the crankcase, which I couldn't disagree with.

 

[super44]

I was able to watch the video, I see what you mean about the revving at the end of the video.

How long has it been since a carb rebuild? I wonder if your fuel pump diaphragm could be getting a little tired and leaning it out? Or metering diaphragm getting stiff.

You'll probably get plenty of advice to have a pressure test done on the crankcase, which I couldn't disagree with.

As far as I know this saw has never been messed with and has been retired until a good refresh has been done. My wife says she never gets tired of watching this tree hit the ground. Thanks for the reply!!!

 

[MacAttack]

As far as I know this saw has never been messed with and has been retired until a good refresh has been done. My wife says she never gets tired of watching this tree hit the ground. Thanks for the reply!!!

That's a wise idea, the last thing you want to do is burn up a 125cc McCulloch!

Keep us posted.

 

[heimannm]

S44 - Are you sure you weren't running out of fuel?

Mark

 

[super44]

S44 - Are you sure you weren't running out of fuel?

Mark

Tank was about a third full. I did notice the fuel line going to the filter seemed a bit stiff and it made me wonder if the filter was not dropping into the gas when the saw was on it's side?

 

[vinnywv]

Got my tank cover and air filter cover back and installed on the 795. Turned out very good.

 

[knightmax]

She's a pretty one...

 

[MacAttack]

I picked up a really nice, new production rebuild kit today for my Mac Flatback carb from @Jeffrey F. Today.

Send him a PM if you're doing a similar rebuild, he's making all kinds of great stuff for old Mac and Homelite saw carbs and gaskets.

 

[MacAttack]

Time for some weird science to re-soften the sparkplug access cover from my 450, which is in very nice shape except the rubber is now harder than plastic.

3 parts isopropyl alcohol and 1 part wintergreen oil...soak for a few days and see what happens.

 

[knightmax]

Time for some weird science to re-soften the sparkplug access cover from my 450, which is in very nice shape except the rubber is now harder than plastic.

3 parts isopropyl alcohol and 1 part wintergreen oil...soak for a few days and see what happens.

I have Reproductions of those if you ever need them.

 

[Squareground3691]

She's a pretty one...View attachment 1217117View attachment 1217118

 

[MacAttack]

I have Reproductions of those if you ever need them.

That's good to know! I would have assumed replacements did not exist.

 

[MacAttack]

My Mac Flatback carb is refusing to pump and / or deliver fuel. The primer works beautifully and it will give me about one second of gratifying barking, but it will not run after that. It's just running out of fuel until I prime it again.

I made sure the carb is fully seated on the flange, and I re-assembled exactly like the original parts.

Any suggestions where to start?

I've already given my Tillotson carb a pep talk in case he gets called into the game...

 

[Jeffrey F.]

My Mac Flatback carb is refusing to pump and / or deliver fuel. The primer works beautifully and it will give me about one second of gratifying barking, but it will not run after that. It's just running out of fuel until I prime it again.

I made sure the carb is fully seated on the flange, and I re-assembled exactly like the original parts.

Any suggestions where to start?

I've already given my Tillotson carb a pep talk in case he gets called into the game...View attachment 1217404

Make sure the vacuum holes aren't plugged or blocked in anyway. I sounds like you aren't getting any pulse from crankcase.