Carter YH Carbs?

I wonder if they did (do) get much more out of a downdraft. Remember we talked about just how many cfm each single barrel Carter side draft was. Somewhere, to my surprise (I think you talked to someone) we discovered that they were (with the two of them together) pretty decent cfm (never really got a final exact number as I recall). But, the 312 info., not as much applicable to the marine applications, indicates that you could get over 300hp out of the 312's with a Paxton Supercharger, but that was more for Ford's cars and trucks of the era. The Marine Interceptor 312 seems to consistently say 215 hp. I wonder how much (if any) more horses can be gained with a 4 barrel on the 312. Not that I'm planning on that. I know, as we've discussed, the 2 single barrel Carters keep the hatch height low and (at least with the Dunphy X-55's) to add a 4 barrel necessitates some raised scoop on the box or a higher box. Just wonder about the potential increased hp. Kind of figure it might do a little, wouldn't it (somewhere between the 215hp (with 2 single barrels) and 300hp+ with the Paxton)?

Ooo! Pete; did you add that pic after you posted? I didn't see it the first time I read your last reply. Nice.

Thanks Pete. I'll check for the manual there. Hmmm? Not sure? I noticed it once after I ran it briefly (which has only been like 2 or 3 times - summer before last). My plan was to hook the battery up and turn it over with the coil wire unplugged sometime here soon because it's winterized now but I didn't start it all this past summer. I may have to wait until spring to find out for sure, but I'm keeping notes and I "will" get to it. I noticed it at the rear one but I've heard it said, and it makes sense, that either one, if leaking, will put gas there because of the engine angle.

Pete and/or Riley -- Interesting thread. So, where is the YH carb info. that you guys were discussing? Sounds like you (Riley) mentioned it should be somewhere on the web site here?

My 312 runs, but so does one of the 2 carbs (literally, it "runs" i.e. leaks onto the intake as described above).

This sounds like info. I'm also gonna need too in the future to eliminate that. Appreciate any links to what Pete described above as the "real nice section on the carbs" in the Interceptor Y Block manual.

75 stang wrote: my guess is it would be cheaper to send them to the nearest CC dealer for a rebuild than buy a rebuilt set.

Im not so sure about that- I know that I sure wouldnt necessarily be looking to a CC dealer to rebuild my vintage carburetor! If its not a job you want to tackle yourself, stick with a good rebuilder with good references (dealer or otherwise), as I suspect most dealer service depts lack a tech who has ever had one of these carbs apart.

Pete, Reid gave it to me and I scanned it and sent it to the site. He must have had some sort of preminition because after giving it to me we've ended up with 2 Interceptors.

Pete, is the Y block manual different than the one in the reference section?

Adam,
Dig into the carbs!! You telling me you are doing the engines tells me you do have mechanical skills. I too have done engines and I too was always afraid of carbs but then one day I had to rebuild a up draft. That taught me they really aren't that complicated. The YH's aren't like a 4 bbl. with lots more parts!

So, since you're at the last stages of the rebuild, I now know you haven't tried to run the engine yet. Maybe you'll be surprised and it will run fine!!

The biggest problem with the YH's is the aft carb would puke gas out the arrester when the float needle sticks open. This was the downfall of the side drafts.

Adam,
First, why do you feel you have carb problems? describe whats going on.

If you luck out finding the carbs, I don't know if the seller will be able to set the float levels correctly. If rebuilding is something you don't feel you can handle, maybe you should look for someone to do it for you. You'll need him anyway for the floats.

Adam,
You want complete carbs or just the rebuild kits? Kits are available. I just did a search and came up with thousands of hits on "Carter YH". Here's a source for kits. yh rebuild kit

If you do rebuild, don't set the float levels by the specs that come in the rebuild instructions. That spec is for level carbs!! Do you have the Interceptor 312 manual? There are some float level specs in it for the forward and aft carbs. They are a starting point.

Hi all!

I'm looking for rebuilt Carter Sidedraft Carbs for my 312 Interceptor. Anyone know of a source for them? I believe they are YH's.

Thanks!