Stihi Carb

GoldenMotor.com

dogcatcher

Well-Known Member
Nov 11, 2016
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Knowing that the Chinese and the supply chain in the States watch threads like this, I wonder how long it will be before one of the big suppliers start offering these carbs and a manifold for sale. Or will they attempt to reinvent the carb with a version of their own???
 

cannonball2

Well-Known Member
Oct 28, 2010
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The pumper style carbs have been run for a while. There are adapters out there to bolt the carb directly to the engine and another to use the cone style air filter, but most I have seen are $40 for the pair. Almost 3x the carb cost! That's the reason I made my own manifold set up. Not very pretty but works great.

I had not researched these carbs for a while and was really surprised how cheap the are now. A carb like this used to be in excess of a hundred bucks!
At $16 I gambled and won. All of my CGs will have one.
 
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Ron344

Member
Oct 13, 2012
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I have been using these carbs for long time now. The ones I use are 22m. I have three motors with them and a reed valve case inducted. I really like that gear set up you have. That's a great idea.
 

cannonball2

Well-Known Member
Oct 28, 2010
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Thanks yall!

Ron344
The gear setup was a hard won battle but works great. It's a bit different than most hubs in that top gear is 1:1 instead of being overdriven. This means lower ratios in the first two gears allow for the top gear to carry a higher ratio than the more common hubs that have a 1:1 middle gear and only 1 lower gear.
This hub is locked also so pedal starting and engine braking are possible. Plus it's more heavy duty than most.
This carb has added some power but think the bike still a bit over geared. Cruises at a very relaxed rpm at 35 which is fast enough.
 

Ron344

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Oct 13, 2012
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That's really cool! I like how simple its and the size is perfect. My bikes have enough top end I'd like more low end that might help.
 

cannonball2

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Oct 28, 2010
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Thanks DC
It's good to have the initial settings. I really never counted the settings after setting them up on my bikes. Guess I should do that. The carb is way rich as received.
As I thought the idle speed screw is part of the saw and not the carb. Idles fine as is.
 

dogcatcher

Well-Known Member
Nov 11, 2016
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I have saved all of the info you and others have posted, I will eventually put it all in pdf format. Once we finally get spring and the cold weather is past us, I want to try this. Is there anyway to post a pdf on a thread, if it hasn't ever been posted on the Internet?

here is the info about the air filter needed for the carb.
Stihl c.jpg
 

Ron344

Member
Oct 13, 2012
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I keep thinking of that hub? it looks like if it's on the left side like that it would turn backwards, is that what you mean when you said it's locked up? I've never seen one that's left side drive or can it run in either direction? Just wondering!
 

cannonball2

Well-Known Member
Oct 28, 2010
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Yeah its odd.
I set out to make a geared hub drive with it all on the left. In other words no jack shaft. It's a Sturmy Archer fixie hub. A normal hub in that position would just free wheel. This one has no free wheeling. It wouldn't matter what side you ran it on. I have built several bikes that run the Shimano Nexus. The drive has to cross to the right to do it. I wanted to simplify that. I call it a concentric transmission, it's similar to the separate engine/transmission motorcycles.
Also you can't pedal start the common geared hub. This one you can. This hub is stout it easily handles the loading of pedal starting. I normally start it in second. The normal derailleur shifter bike works well but is very busy gearing up and down. The geared hub can be stopped in third and shifted into first sitting still. This build works very well and the only issue has been the loss of a master link on the secondary chain. I repaired it as an endless chain and expect no further issues.

The build is threaded here on the forum. Don't remember the title, though it shouldn't be too hard to find if you search my profile.

To further use the geared hub I drive one backwards on the left side on a friction drive. That is the strangest build I have done. Uses a Maytag twin cylinder engine.
 
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cannonball2

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Oct 28, 2010
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Thanks Curt!
As crazy as this build is it works well and is easy to ride. The little Maytag doesn't make much power but thanks to the geared hub it will make 20+.

It is in its own way like riding was early in the last century, slow and relaxed.
 

curtisfox

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Dec 29, 2008
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That's the way i remember it, and about the only thing i have ridden seance is a friction drive, about the same speed. LOL Sure is Kool what can you see doing it, and would miss in a car or going faster. Take time to smell the roses.
Just love your simple approach to building, instead of all the high tech, like this carb change. My build has a 1 3/4 hp Lauson, with home made clutch, ( hope it works ) it to should be fun to ride...........Curt
 

Ron344

Member
Oct 13, 2012
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Thanks CB for information on the hub. I would really like to try that on one of bikes, maybe the next one I build. I also really like your Maytag build I remembered when you started building it I just didn't remember hub on it. Nice job on the fiction drive.
 

SpearrowsPearl

New Member
Sep 16, 2018
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41
Seems experimenting with carbs is a fun pass time for me. Having been in the small engine trade am well versed on Walbro and Tillotson carbs. Now that the Chinese have started making clone chainsaw parts I decided to gamble 15.95 shipped on a carb for an 041 Stihl. Seemed a good choice as the 041 is 61cc.
Cobbled up a manifold for it and gave it a run. After a few tweeks on the hi/lo needles I had an excellent running gt5. Super clean carburation from idle to a much improved top end. No flats or 4 stroking and a perfect idle.
Was really suprised at the throttle response. I expected it to maybe be an issue as the carb is 21mm. Pretty big for a stocker. However these type carbs run larger bores than a M/C type. Shortly after getting in a few hi speed runs the chain let go.

I have gotten the NT carbs running pretty good, but there is no comparison to this carb. Time to repair the chain and figure out an air filter. I plan on ordering a couple of more and one for a Stihl 660 for the 90cc Stihl Frankenstein build. To heck with changing jets!!
. View attachment 97498
Hello I just built my first Motorized bike. I read what you did for a new carb . I also have the 80cc/66cc engine. I got it from gasbike.net what I got from your what is the device in line with your chain?
[ View attachment 97518 So l have been riding this setup quite a bit today. It's absolutely perfect!! I fabbed up a shorty intake and an air filter made from a Crosman pellet tin. It all fit easily into the normal space of the NT carb. Air filter is neat because it has a screw on lid that makes getting at the filter easy.

So the conclusion is if you are looking for a easily adjustable carb that runs light years better than most this is it. No freeking jets to ever have to fool with!! Light fabrication is all that is necessary and the stock throttle cable works. Plus it's only 16 bucks shipped! The exhaust limits this bike a bit as it's restrictive. Can't wait to get this carb on the Zeda 80 with the boost pipe. View attachment 97519
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
Its a Sturmey Archer 3sp fixie hub used as a transmission.
Works well. Only a fixie hub will work on the left. I wanted a trans set up that didn't require a crossover or the complexity of a normal shifter bike. Its much easier to use and gears can be selected sitting still.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
So now that the weather has cooled at bit the MBs hit the roadroad almost daily. I really like this carb! With temp swings from the 40s to the 80s the adjustment capability is really nice.
Have been riding the bike with the Zeda 66cc and the modded Zeda boost pipe. The carb is works well with this set up.
I would reccommed this carb if one has the ability to fit it and understand its adjustments. Its a good clean and consistant runner. Its better suited for a high end build but does fine on a stocker so long as its geared to rev. Has a decent bottom end and a great idle, but rips when on the main circuit. would be a good carb to work engine mods with as its just a needle twist to accommodate changes, not a search for the right jets.
 

mezzenger

New Member
Nov 15, 2015
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Hey Curt
Yeah running Walbro carbs has been done for a while so this is nothing new(actually I believe this one is a Tillotson clone). Its just that the carbs are so cheap now it was time to do it.

There are adapters out there for both mounting the carb to the engine and for mounting an air filter which pretty much makes it a bolt on. I just used what I had to make it work.
It's a great running set up.
Where can I find those adapters?

Thanks.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
223
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Colonial Coast USA.
The ones I used were made from stock intakes as described in the first part of the thread. There were some sold by various sellers on the net, you will have to search for them to see if they are still out there. Seems like they were in the $30-40 range.