McCulloch Flatback Carb Kits

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Mastermind

Work Saw Specialist
Joined
Nov 21, 2009
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I can't send PMs on this site.....so I'm hoping to talk with Mark about the Mac flatback carbs.

I have both a 640, and a 660 with flatback carbs, and would like some guidance.

Thanks in advance.
 
I am no expert Randy, but did a few last year. What are you wanting to know?

Thanks for the reply Don.

I'm looking for any and all tips and/or tricks to make these run well.

I also need to know where I can get a kit for these.

I sent Mark a message for you.

Thank you Gary.

I'm feeling like a second class citizen here.....
 
I have access to maybe a half dozen of em. Boy they sure make good hot saw carbs.
Here's a diagram of this model. I know it's easy to just look up on acres site, but I actually didn't think it existed on there because I didn't know it was a walbro brand.
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I got mine from the guy in Marysvillle Washington on Ebay. He occasionally runs out but has more made up eventually. They were around $40 last I checked.

Well I have two flatbacks that will not draw fuel and run even after being, what seemed like, well cleaned and two different new kits tried. Sheldon (Torinocobra) said that sometimes you have to sonic clean them to remove everything under the welch plug.

As far as hotrod tips, I could not tell you as I have kept mine stock.
 
I got mine from the guy in Marysvillle Washington on Ebay. He occasionally runs out but has more made up eventually. They were around $40 last I checked.

Well I have two flatbacks that will not draw fuel and run even after being, what seemed like, well cleaned and two different new kits tried. Sheldon (Torinocobra) said that sometimes you have to sonic clean them to remove everything under the welch plug.

As far as hotrod tips, I could not tell you as I have kept mine stock.

Chainsawr had the kits.......with shipping about 40.00.

These will be used on a 640, and a 660 geardrive......so they will be all stock.

I think i have a flatback service guide in my Mac stash, I'll go looking.

That would be cool. :)
 
Just trat them like s normal carb then Randy. I believe my 660 and 640's have chokes but will have to look. If not then there is the imfamous non-rebuildable primer pump. If they work, great, if not then manually prime.
 
Chainsawr had the kits.......with shipping about 40.00.

These will be used on a 640, and a 660 geardrive......so they will be all stock.

That would be cool. :)
Attachment pages 5-9
 

Attachments

  • Mac_ShopManualSupplement_63328.compressed.pdf
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Both of my 640's and my 660 all have the primer pump. I am surprised at the 660 as it is supposed to be a super 250 (which is a Tilly with choke) with a geardrive where the 650 is the less hot 87cc engine connected to the same compact geardrive the 660 has.
 
Both of these saws have 640 stamped in the case.........I may have been wrong about one of them being a 660.
 

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