Mc5 Carb ID
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- Scott Kneisel
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Mc5 Carb ID
Can anyone tell me (Tom S??) what Tillotson carb the Mc5 engines were shipped with? I have seen a couple versions in some pictures of NOS engines but I would like to put the correct carb on the one I am restoring right now.
Thanks in advance,
Scott
Thanks in advance,
Scott
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Re: Mc5 Carb ID
Scott, the early Mc-5 carb was a modified 1-51/61 chainsaw carb, P/N 50687A. The idle fuel pickup hole was enlarged to .052" (#55 drill). I think I have about 20 of them if you don't have the right one. Tom
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Re: Mc5 Carb ID
I remember seeing an HL 63 on an Mc 5 a buddy had. I think we also had one on a dual carb Mc 6 with the Mac carb over the main intake ports, and the HL 63 over the third port (without reeds).
- Scott Kneisel
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Re: Mc5 Carb ID
Thanks Tom & Mike,
I looked thru my old saw carbs box and found a bunch of them. I picked the nicest one and cleaned it up today. I also took the lever type choke off another carb and installed on the HL63. The carb looks like new. The only thing I don't have are the correct H&L needles that are adjustable without a screw driver. The carb takes o-ring type so later model needles won't work. I remember having a couple carbs with adjustable o-ring needles but apparently they are long gone. If I feel picky enough, I might braze on adjustable extensions to the saw needles just to have the correct look.
Thanks again,
Scott
I looked thru my old saw carbs box and found a bunch of them. I picked the nicest one and cleaned it up today. I also took the lever type choke off another carb and installed on the HL63. The carb looks like new. The only thing I don't have are the correct H&L needles that are adjustable without a screw driver. The carb takes o-ring type so later model needles won't work. I remember having a couple carbs with adjustable o-ring needles but apparently they are long gone. If I feel picky enough, I might braze on adjustable extensions to the saw needles just to have the correct look.
Thanks again,
Scott
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Re: Mc5 Carb ID
Scott, does yours have the steel fuel inlet cover? TJ
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Re: Mc5 Carb ID
McCulloch recommended using an HL93A kart carburetor and a .017" head gasket on an Mc-5 for a claimed 20% power increase over stock.
For a 31.5% power increase add special piston with thin racing rings P/N 48695.
Thin rings added 10% for the Mc-10 also.
Back then the carb P/N 48703A cost $18.00, head gasket P/N 48742 cost .35, and the piston P/N 48695 was 10.25.
It appears you could put kart needles in a saw carb if you enlarge the outer opening or pocket to the size required for the tapered seal, washer and spring to fit into.
For a 31.5% power increase add special piston with thin racing rings P/N 48695.
Thin rings added 10% for the Mc-10 also.
Back then the carb P/N 48703A cost $18.00, head gasket P/N 48742 cost .35, and the piston P/N 48695 was 10.25.
It appears you could put kart needles in a saw carb if you enlarge the outer opening or pocket to the size required for the tapered seal, washer and spring to fit into.
Last edited by Tom Smith on Tue Sep 20, 2011 5:28 pm, edited 2 times in total.
- Scott Kneisel
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Lotsa' other Macs - User Agreement: Yes
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Re: Mc5 Carb ID
Yes it does have the steel screen cover and original top plate. This one will be all original (well mostly that is)
On another note,
Actually I built an "hopped up" Mc5 last year to compete with Ted at TBO, we both built them but Ted couldn't make it this year, we will get together sometime even though we are 3000 miles apart.
So my built engine has a real nice Mc5&6 block , stock ports with a 30 over thin ring piston, stock stroke, thin head gasket, Van Tech manifold with an HL250 on top with a modified older type top plate.
I have not fired it up yet, waiting to meet Ted someday
Attached are a couple pics.
I really like the older engines.
On another note,
Actually I built an "hopped up" Mc5 last year to compete with Ted at TBO, we both built them but Ted couldn't make it this year, we will get together sometime even though we are 3000 miles apart.
So my built engine has a real nice Mc5&6 block , stock ports with a 30 over thin ring piston, stock stroke, thin head gasket, Van Tech manifold with an HL250 on top with a modified older type top plate.
I have not fired it up yet, waiting to meet Ted someday

Attached are a couple pics.
I really like the older engines.
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Re: Mc5 Carb ID
Scott,
Is it stock?
I have a cheater MC-5 that I just got running. Not quite as pretty as yours though.
I used Jeff Campbell's MC-5 clone video as a guide. I plan to test it against my stock MC-10 soon.
The MC-10 has been running fine for a few years. My Son like it better than the MC-92.
Anyway, bring it to Barnesville!
Terry
Is it stock?
I have a cheater MC-5 that I just got running. Not quite as pretty as yours though.
I used Jeff Campbell's MC-5 clone video as a guide. I plan to test it against my stock MC-10 soon.
The MC-10 has been running fine for a few years. My Son like it better than the MC-92.
Anyway, bring it to Barnesville!
Terry
- Scott Kneisel
- Posts: 477
- Joined: Mon Mar 24, 2008 7:48 pm
- Vintage Karting items owned: '63 Rupp Grand Prix, 66 Rupp Chappy, Mc6's, Mc8, Mc10's, Mc20's
Lotsa' other Macs - User Agreement: Yes
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Re: Mc5 Carb ID
Thanks Terry,
Can only bring one kart to Barnesville, it will probably be for the Mc49 class.
The Mc5 will just have to wait....maybe Avon or TBO next year.
Scott
Can only bring one kart to Barnesville, it will probably be for the Mc49 class.
The Mc5 will just have to wait....maybe Avon or TBO next year.
Scott
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Re: Mc5 Carb ID
Beautiful engine, Scott, as always! I was going to put the HC12 Crescent carb on the Hovey manifold for mine, but I pirated the Hovey and modified it to feed the Mc101 on the Swoopster. I will find some other period correct manifold. Charlie graciously gave me an original Mc5 crank, so I won't be using the beautiful modded saw crank you made. That way I'll be able to use a 10 or 11 tooth drum. The rest is very much like Scott's. +.030, squared exhaust, stock intakes, .012 gasket, small golfball head. Scott, I will try to catch up with you next season! Ted