walbro carb identification

[jerrycmorrow]

got this carb from a fellow AS member. been on the Walbro site searching for its application. There are several SDC carbs there and about 5 - 6 SDC-38-1 carbs but can't find any SDC-38A carbs nor any combination of letters/numbers as stamped on the carb.

other than the 62-36 stamped on the choke valve and the 34-51 stamped on the throttle plate these are the only characters on the carb. prolly some inside but i haven't disassembled it. not really a big deal but i'd like to know that 1) it is, in fact a SDC-38A model and 2) what saw, or other machine, did it come from. preciate it.

 

[w8ye]

The SDC-38A is obsolete and no longer available

The venturi is 19.05 mm

The repair kit is a K10-SDC

 

[67 Mustang]

Acres has one listed on the Mac 81.

Model Profile: Super Pro 81E

 

[jerrycmorrow]

i'm guessing that it came from a larger mac since the SDC-38-1 on the Walbro site did. is that correct?

 

[w8ye]

The SDC-38 was used on the MAC's

CP-80
Power Mac 570
Power Mac 850
Super Pro 70
Super Pro 81

 

[jerrycmorrow]

The SDC-38 was used on the MAC's

CP-80
Power Mac 570
Power Mac 850
Super Pro 70
Super Pro 81

thanks. guess i may have a nugget for some mac-head someday.

 

[Fish]

thanks. guess i may have a nugget for some mac-head someday.

That is one "lofty" goal....

 

[jerrycmorrow]

That is one "lofty" goal....

nah. i'm just sayin that, because its obsolete, when someone's looking for one i got one. i'll pass it on for what i got in it. only arrowhead knows how much that is.

 

[Fish]

Yes, the older I get, the more I realize how much these oldy parts
are worth holding onto.

 

[knockbill]

nah. i'm just sayin that, because its obsolete, when someone's looking for one i got one. i'll pass it on for what i got in it. only arrowhead knows how much that is.

if taht carb will fit a mac 250, i'd be interested...
thanks,
john

 

[w8ye]

I don't think that carb ever came on a 250 but it is a perfect size carb for a 80 cc engine

 

[knockbill]

I don't think that carb ever came on a 250 but it is a perfect size carb for a 80 cc engine

well,, my offer still stands,, maybe one teh mac gurus will be able to tell us...

 

[Eccentric]

Replying to an OLD thread..............but that carb won't work on a McCulloch 250. You need a Tillotson HL. Best fit would be one of the HL63 carbs such as an HL63E, HL63F, or HL63G.

 

[knockbill]

Replying to an OLD thread..............but that carb won't work on a McCulloch 250. You need a Tillotson HL. Best fit would be one of the HL63 carbs such as an HL63E, HL63F, or HL63G.

just saw your reply,,, yep, thats what i found also,,, tillotson hl carbs were also used on mac 250's... mine has a flatback on it, and the primer doesn't work well, and teh rebuild kits were pretty expensive, as i recall.... so, its the only saw i have that doesn't get in teh firewood rotation...

 

[Roanoker494]

There are aftermarket "flatback" kits available now for about $30. I don't believe a HL is a direct bolt on replacement without the little adapter plate because the impulse holes will not line up.

 

[knockbill]

There are aftermarket "flatback" kits available now for about $30. I don't believe a HL is a direct bolt on replacement without the little adapter plate because the impulse holes will not line up.

i'm pretty sure some 250's came with hl's with chokes,,, the choke button should line up with teh primer button hole...
not sure if teh carbs are direct replacement, or used adapters,,,but, even $30.00 is pretty steep for a carb kit, and then you still have to deal with the primer, which i believe isn't rebuildable...

 

[roncoinc]

Next time you need to know what a Walbro fits go here.

DivShare - Folder - CarbStuff

go to the walbro folder,,go to carbguide.pdf,,open it and at the top in the "find" box put in what you want to find.
each time you hit enter will go to the next find.
will give you make and model and repair kit numbers even metering spring part number.
you will have to wait 15 seconds to download a file if you are not a member.
I have over 46 megs of carb stuff stored there

 

[Eccentric]

There are aftermarket "flatback" kits available now for about $30. I don't believe a HL is a direct bolt on replacement without the little adapter plate because the impulse holes will not line up.

i'm pretty sure some 250's came with hl's with chokes,,, the choke button should line up with teh primer button hole...
not sure if teh carbs are direct replacement, or used adapters,,,but, even $30.00 is pretty steep for a carb kit, and then you still have to deal with the primer, which i believe isn't rebuildable...

McCulloch 250's made in 1964 had flatbacks (according to McCulloch). After that, 250's had HL's. NOT talking Super 250's here. That's a different subject (they used both HL's and choke equipped flatbacks). McCulloch did indeed use a cast adaptor plate on their front tank HL equipped saws as Johnnie stated. If you get an HL from a front tank McCulloch, make sure you grab the adaptor plate too. The top tank McCullochs did not use an adaptor plate, as the impulse passage on those lines up with the HL. Flatbacks have a passage cast into the mounting flange that allows them to be used on both top tank and front tank Macs without the adaptor (although they did still use a thin steel spacer on the front tank saws). The primers on flatbacks aren't rebuildable, but are replaceable as a unit. The last two NOS primers I saw sold in feebay went for $25 and $50....

 

[Roanoker494]

I have often wondered if you could grind a passage into the carb flange on the saw so that a HL could be used without the plate. You could bolt a HL gasket to the flange, to mark where the impulse hole needs to be, then use a small burr bit to grind a passage between the two points.

 

[Eccentric]

I have often wondered if you could grind a passage into the carb flange on the saw so that a HL could be used without the plate. You could bolt a HL gasket to the flange, to mark where the impulse hole needs to be, then use a small burr bit to grind a passage between the two points.

That would depend on how much material there is in that area of the flange. You could also groove the flange on the HL so it mimics the flange on a flatback. You'd then use the thin steel spacer plate that had neen used with the flatback. Ther is one other issue though. The AF stud on the carbs meant for front tank Macs are located on the carb body so everything lines up when the adapter plate is used. If you eliminate the adapter, then the carb, AF, and AF cover will be too far forward. This may effect the throttle and choke linkages too.