Unboxing and review of the OBR 1242 carb – O’Neil Brothers Racing – 1/5 scale
So here you can see we have the 1242 car from obr. It is pretty similar as the 990 car which most guys use and prefer to use as they’re easy to tune here. I have a 990 to compare it next to, as you can see, there is a little bit of difference on here and we will tear these apart and look at the differences on the internals and externals of the carbs, so at first glance, you’re going to notice This black primer bulb compared to the clear primer bulb. Now a lot of guys would say that they would recommend a clear primer bulb, so you can see the amount of feel in there, but you can also notice that the feel return line, which would be your clear line on top up here coming off you’ll, be Able to see feel coming out of that so there’s no really reason to have the clear one. Yes it’s nice, to see the visual, but the fact is, you can see in the return line feel coming out back to your cars. I’Ll demonstrate for you to let you know that your primer ball is full, so here’s, a quick demonstration to show you that you don’t need to really look at the bulb as soon as you see, fuel coming out of the line on the return. You’Ll know that you’re getting feel see just feel there now and your bulb is full. So as long as you can see this you’re good to go.
So the reason that this primer bulb is black. It is ethanol resistant compared to the standard one. This one will change in color will start to yellow it will start to crack. It will start to leak where this one is resistant and it’ll. Last you a long long time, probably the entire life of your carburetor. So not only do you get the black ethanol resistant primer bowl, you also get the heavy duty primer bowl plate, as you can see that it’s contoured for strength, and it covers more of the surface area which is going to make it have a better seal. Here. You can see the difference between the two. You can see the contour here, which is going to give it more strength, it’s going to be heavy duty. You can see it covers more of the surface area where it doesn’t on the standard, 990, carb and we’ll go ahead and open this up and remove our purge body. So that way we can check out the field metering chamber here. You can see the difference between the heavy duty primer ball plate compared to the stock factory, one on the 990, and you can see that this definitely is a lot better heavy duty plate compared to the factory one. Now the fuel pumps you can see are pretty much the same, not much difference here and we’ll go ahead and remove those and now we’re going to get to our gasket and our diaphragms.
Here we have the factory paper diaphragm, which is made of a fabric covered with a rubber walbro, had a hard time creating a seal around the rivet which created a leak path. Here you can see the rivet and they would have trouble with it leaking underneath the rivet. Now on the 1242 carb, you have the spiral metering diaphragm, which is made of a stainless steel. It has a high grade, teflon membrane. The spiral diaphragm was the first major change in over 60 years, which is impervious to the effects of ethanol and does not deteriorate with age. Compared to the paper diaphragm. The paper diaphragm will deteriorate stretch which will eventually leak. So here you can see the stainless steel spiral diaphragm, and here is the high grade teflon membrane, sitting right here on top. So here you can see on the paper diaphragm uh that i was talking about. You can see the rivet going through right here and with the washer. This is where they’re having trouble creating a seal which would make it leak and not last compared to the spiral diaphragm now we’re going to get into the fuel metering chamber, which is this area right here. What we have is the inlet needle the metering lever and the spring, which is underneath, which makes it rebound so what happens here? Is this pulsates up and down super fast, which allows field to go underneath the inlet needle to the engine? So the 1242 comes with an upgraded metering lever and a softer spring.
This is going to allow more feel at a lower rpm, and here we have the 990. As you can see, has the standard metering lever, standard spring obr went ahead and put in all these extra upgrades. So that way, your carburetor is more bulletproof. You have the teflon gasket the high grade, teflon membrane, uh, the stainless steel spiral. Diaphragm, your ethanol resistant primer bulb uh, but this carburetor not only will take pump gas or petrol whatever you guys decide to call it um 87 through 91. That also will take 100 110 to 116 and straight ethanol by itself, for you dragster guys. So here you can see with the paper diaphragm that it will eventually leak between the rivet and the paper as it will deteriorate from the ethanol. Here you have the high grade, teflon membrane. You can see that clear coat over the stainless steel. That is the membrane itself, so this will eventually leak in the center where this one is solid and it will never leak. So i want to go over a little bit of care with you guys on your carburetor uh, but i also want to make a comment that obr spent the extra money with walbro designing this and giving you the ethanol resistant gaskets. Your heavy duty, teflon membrane, your spiral, diaphragm, your heavy duty, primer bulb that is ethanol resistant. That way, your parts don’t deteriorate on you, but i also want to go over the fact that you want to avoid damage to your carb as ethanol can affect soft parts.
Like the diaphragm, the fuel pump gaskets, it also attracts moisture, causing corrosion on aluminum parts, which would be your car body itself, so make sure that you use fresh feel remove any fuel if it’s going to be over six weeks or more. By doing this, you won’t create any corrosion on the aluminum and deteriorate any parts in your carburetor itself. You can do that simply by removing your black feel inlet line on the bottom of the carburetor, which is right here and just push your primer bulb until it extracts all the feel out of your exhaust line. So here it is guys the 1242 carb just wanted to go over some of the information, the differences on this 1242 compared to the 990., even though they do look similar. This is a heavy duty. Carburetor it’s, going to last you a long long time. O’Neill brothers racing also has a board out version where they machine this out, bigger, so it’s going to have more air intake to go with the velocity stack. But this is an awesome. Carburetor definitely recommend this carb, as you can hear from dan. I asked him a few questions and check out this clip all right, so it has um has the lower pop offspring in it, which delivers more fuel at lower rpms, so it’s got all the goodies from walbro, so internally it um. You know we did our changes and then walbro did what they they wanted to put all the you know, extra stuff on it and that’s what the 1242 is and it tunes just like the 990, the tune’s actually a little leaner because of the pop off spring.
Okay, you’re a little leaner on the tune, usually about one and a half or like one and a half on the high, and one turn on the low is where i set them and then i’ll tune from there and then did you work with them to build. This or oh yeah yeah, we um, we approached them to do our own carburetor and um. You know we’ve we’ve known uh chris at walbro for a long time and he’s like yeah. Well, let’s do this this and this and we went in development with them and that’s what we came up with so it’s great for stock engines, and it works even better for modified engines all the race guys. All the whole team runs on Music dot com. I hope you guys enjoyed the video on this carburetor. The review uh it’s great carb uh. This is gon na give you more horsepower compared to the 990 it’s, a bigger carburetor, so you’re going to have a better fuel, better air intake. I asked for walbro to send me a dyno of the 990 compared to the 1242. Unfortunately, i haven’t got a response back from them. I hope you guys enjoyed the unboxing and review on this 1242. Badass carburetor. Definitely can’t wait to throw this in the truck and see how it does, if you guys, like this video or any other ones, that i do please give it a thumbs up. It will help the video populate in the channel.