Let's Talk Carburetors--

[Brian Rupnow]

Ever since I started building small engines about 13-14 years ago, the purchased carburetor I have used is a Traxxas Pro-15 carburetor. They have worked excellently for me, but the price has shot up from $39 Canadian to $114 Canadian. This has became more money than I like to spend. I have built a number of small carburetors, and they worked, but they take a full day of my time to build one, and a full day of my time is worth about $300 Canadian .My engines usually are around 12 cubic centimeters, they are bench mounted, and never turn over in flight like for instance an airplane engine does. These Traxxas carburetors have no float bowl, and depend on "suction" from the carb venturi to suck fuel up from a gas tank which must be located lower than the carburetor. This morning I did a web search for carburetors suitable for a 12cc engine, and found that there are dozens of different carburetors for less than $50 available. Some of them have float bowls, some have diaphragms, and some seem to be straight thru bores similar to the Traxxas carb. Does anyone here have a recommendation for a moderately priced carburetor suitable for the type of engines I build, that they have used and had good experience with?----Brian

 

[Vietti]

I have used the O&S 35 (?) carbs with good success in models of your size. I can check the number if you are interested. Don't know the prices. Perrys work well too.

 

[Brian Rupnow]

Vietti--Please check the number for me and I will see what it would cost in Canada.---Brian

 

[Ghosty]

Brian,
Because electric has taken over with modeling of smaller models, the supply has stopped and the prices have shot up, engines 15's and 20's have almost gone up 300% in the last 10 years. Getting parts for them is getting harder to source.
I will have a look around and see what can be found, but you may have to bite the bullet and build you own now.

Cheers
Andrew

 

[Gordon]

Actually I have had better luck with building my own than the commercial ones. Easier to change jet size and venturi size. I have a couple around and play around with variations until I get what I want.

 

[Vietti]

Brian,

Memory poor. The carb I like is an OS 3A, don't know where to get a new one, but try Tower Hobbies for similar size carbs.

I miss spoke, the carb I really like is the Enya 09 TV. I got it from MECOA aka Modeler Direct.

Another source to try is website The control line store | eBay Stores

Also try ebay.

My experience with building is poor, most worked but poorly. On our small 4 cycle engines I find a small choke size is best, they may limit acceleration and top speed but OK on my engines!

Sorry about the confusion. Agree with Andrew the niche for small glow engines has been filled by electric motors. If you find a carb you like, stock up. Roy Scholl had some real cheap, small Chinese ones but he has been out for some time.

The Enya has a choke size .165"

The OS 3A choke size is .221"

Cheers, John

 

[Brian Rupnow]

Something "fishy" is going on. I just checked on Ebay and there are dozens of Traxxas 4033 carburetors for sale, brand new for $35 American. Add on $10 for shipping and change American dollars to Canadian dollars, and it's still less than $60 Canadian funds. I don't know where I got that $114 price this morning, but it certainly pays to shop around a bit.

 

[petertha]

Great Hobbies (Canada) lists the Traxxas for 50.99 CAD. Not sure about shipping unless there is a store near you to pick up. There may be other Canadian RC online stores too
https://www.greathobbies.com/productinfo/?prod_id=TRX4033
Perry (USA) has a broad selection if you are searching for more specific orifice size in the future. They are not quite the build quality of say an OS carb, but others have had good success & may function the same for stationary engine type purposes. You might want to confirm gasoline proof because of the body material (actually all these carbs are intended for methanol so maybe O-rings & seals might have to be examined in this regard).
Perry Pumps - Carbs

There used to be a lot of reasonably OS & other knockoffs on Alixpress & the like, but I've noticed many have dried up over the years.

I don't have much running experience with the gasoline diaphragm carbs but I think if 2-stroke variety are intended to function with a pressure pulse. I'm not sure how they are adaptable to 4-strokers.