MTFCA Forum

Hello all! For the past spring I shave seemingly tried everything to get my carburetor to smoothen out, with seemingly little success. The carb was cleaned out, dipped in Berryman, adjusted the idle screw and the flow adjustment, and nothing seems to help. It will start up alright, and just run really rough until it just dies. The only solution I have found to make idling smooth is keeping the choke at 1/2 open, which is infeasible to drive. Any suggestions?

Skylar, some carbs (and I assume it's an NH or a Kingston L-4) will respond to a dunk and a swish. Not all do. For the very small cost relative to the agrivation, spend some bucks with Forum member Corey, and get a nicely restored NH for a very reasonable price. That will take the carb out of the equation and let you either drive your car or look for the Root Cause of your problem. So long as you are dealing with what is frankly and unknown condition carb, you are going to simply keep pulling your hair out.

A properly rebuilt NH is the "T" hobby's biggest bargain on the market these days

While it is no guarantee that it is your carb and not a faulty intake gasket or other trouble, there is very little reason to suspect that you'll regret having a "like new" warranted carb hanging off of your car...once fixed right, it is good for years and years of trouble free driving.

The carburetor is a Holley G.

For some reason, everyone I know seems to have mountains of Holley G carbs just lying around. Some older model t enthusiasts have given me more of them, but it’s just a pain to keep checking old carbs to just have them not work again. The rebuilt ones may be a good option!

Send one to Corey Walker in Texas for a rebuild.

Were the idle circuit plugs drilled out before the dip?
Did you confirm the idle circuit passages were clear before re-plugging?

Is the jet in place & tight?
Does the mixture needle seat into the jet before running out of threads or locking on the friction nut?
Set needle to 1 &1/4 turn open to start. Will be rich, but will run long enough for you to lean it down.

There is a LOT more to a good carburetor restoration than most folks realize.
& a lot of experience to restore a great carb.

The above answer assumed an NH, but still applies.

The G has a tiny copper tube that sits in the jet puddle. It must be @ the right height & not leak.
The float was originally cork. Thats a problem issue to seal or build a substitute with the same buoyancy.

Consider running an NH. Its a simpler carb.

Those passages are used up to about 20 mph on all the carburetors and none of the carburetors will work well if they are plugged.

They are especially important to an easy to start engine.

Cleaning those passages is a job best left to the professional carburetor rebuilders.

Reviewing your posts I do now remember you had a "G", and researching your posts, see that you've been suffering with this for 3 years.

One of the nice things about buying a rebuilt or sending yours off is that Corey will test run your carb and thus you will receive a carb that is ready to go from the jump with no fooling with adjustments (at least to get started and warmed up)...NOW if you suffer from same or similar trouble, you still have a "new" carb and can tackle things like a new manifold gasket with full confidence that once the cause of your trouble is solved, you will have a carb that can make use of all of your "fixes"

best of luck

My '17 came with a G. I had it rebuilt and it ran nice. It is a more complicated carb than some. After doing some research, I bought a rebuilt NH from Russ Potter because my reading indicated it performed better than the G. I had a chance to run the engine on a dyno, first with the G then with the NH. The results are shown below. The NH produces more horsepower without a decrease in mileage. If you have a NH you can also take advantage of a Scott Conger Full Flow valve which insures your carb is getting enough fuel on hills or when the tank is low. A good investment.

Get a good NH or find a decent one and get it rebuilt by Kerry Walker here in Texas and your running issues will probably go away. Overall most reliable of T carburetors and parts easily avaliable.
The cork float in the G may be shot if it’s the original. Good luck

Skyler Kimball wrote: ↑

Wed Jul 05, 2023 1:52 pm

... The carb was cleaned out ... nothing seems to help ... Any suggestions?

Skyler,

If you've a mind to enjoy the glow and learning from fixing this yourself I can recommend an ultrasonic cleaner with a suitable solution as a good methodology for cleaning carburetors. This will often get into areas that are otherwise quite difficult, for particularly stubborn issues I, carefully, use stiff brass wire, fuse wire, or carb jet cleaning needles to ensure clear passage.

You might also find this link useful: https://modeltfordfix.com/rebuilding-a- ... arburetor/

Luke.

Thank you all for your help and suggestions! My brother is in our local auto tech course and he thinks he adjusted it correctly. I think I was not adjusting the flow enough to make much difference. He simply figured out how many turns it needs to be open to run smoothly. I was so used to running the carb on a certain setting, I guess when I cleaned it out last time, it needed a completely different setting. Thanks again for all your help!!!

Good for you

that is the point I was making regarding buying a carb that had run and was adjusted from the get-go.

now that you are over this hump, you should realize that there will be a setting for starting, a setting for when it is warmed up (and yet another setting if you ever replace your carb stove).

do a GOOGLE search for "MTFCA how to adjust a carb" and learn about "too lean" and "too rich" and the sweet spot somewhere between those settings

If you can manage to start a car on MAG in the first place, and with a carb that is adjusted too lean, then you have a car that really wants to run, so get to it!

Thanks for the advice concerning the adjustments during certain times, I know some people have the adjustment rods through the firewall, that are very helpful, and I should probably invest in one! Concerning starting, I always jack up the rear wheel to start it. The transmission is just too much resistance on a cold start. I still have so much to work on, but at least now I think I’m gaining!

I can recommend an ultrasonic cleaner with a suitable solution as a good methodology for cleaning carburetors.

Apparently that varies greatly according to which one you buy. I ended up with one which was a complete waste of money.

Steve Jelf wrote: ↑

Wed Jul 05, 2023 11:28 pm

I can recommend an ultrasonic cleaner with a suitable solution as a good methodology for cleaning carburetors.

Apparently that varies greatly according to which one you buy. I ended up with one which was a complete waste of money.

Steve,

It's a shame you got a bad one. They're not the answer to everything, but a decent unit with the right solution can do a great job.

Not sure if yours was a heated one but I think that helps, although the solution will tend to warm up with use over time anyway. I also use different solution depending upon what I'm trying to do; sometimes vinegar, super-rip/alkaline, plain detergent + water, or weak caustic + water. There are many others.

Skyler,

Sounds like you're sorted, good. The mixture adjustment extension really is a must, as Scott implies temperature/pressure changes will necessitate altering the mixture for smooth running and it's so much easier to do so from the drivers seat!

Luke.

In addition to earlier postings on this subject, I too had carb problems in my “T”. Not knowing what I had for a carburetor, I sent mine to Snyder’s for exchange for a rebuilt one. Turned out I found out mine is a Simmons. They don’t offer that carb at the moment so had to look elsewhere. A Friend told me about Potter’s Piston Parlor in Illinois, so I contacted them to see what they had. They came up with a Holly NH which I purchased and received it in three days. I must tell you, I am thrilled with the results with a newly rebuilt carb. My T couldn’t run better now!No more missing, spitting, & back firing. I feared I may break a crankshaft if I continued with what I had. Thank you Potter’s!!

quick shout to Harvey: your Simmons is a very good carburetor - performs very well and is modestly desirable by many people. If you still have it, it is worthy of investing a modest sum to get it refurbished properly.

Thank you Scott for the advice! Yes, it certainly will get refurbished professionally and kept for a future T project.