MTFCA Forum

Hi Folks, it has been a while since I posted on here. A friend passed away and his son has asked me to help get there 22 Runabout going. It has been setting for several years, and I took the carb apart to clean it out. The float level was extremely high when I got it apart and I am not sure what the issue is. I would guess it is the needle and seat but would like to get the opinion of some experts. I have several pictures and think it might have an incorrect needle and seat, maybe too tall and that is causing the issue.
Let me know your thoughts and suggestions.
Thank you

Are there 2 gaskets under the valve seat?
Sometimes there is an extra one is left in by accident during a "rebuild"

That is a Gross jet. They can be a problem if you have trash in the system.
Do them a favor and get one of Scott’s full flow valves.

Dan Hatch wrote: ↑

Fri Jul 04, 2025 8:08 am

That is a Gross jet. They can be a problem if you have trash in the system.
Do them a favor and get one of Scott’s full flow valves.

DITTO!

That Grose Jet replaces the NH seat and threads in, these give grief as they are made for pressure fuel systems.

And IMO your friend's carb is so rusty inside, lots of material decayed, perhaps the passages are also rusted closed some, best to ream out those or find a better looking NH core.

Gross Jet on far left, being replace with Scott's Full Flow seat which has correct size orifice and a regular needle valve.



Full Flow set up.

Check for double gaskets at the valve seat... Spray the whole carb and parts with carburetor cleaner correctly. Set the correct float level with the grose- jet intake valve. .... And enjoy!.... off the top of my memory, I'm thinking the float level measured from the carburetor flange should be 15/64" holding the carburetor upside down in your hand, and measured 180° opposite the intake valve.... Check the pivot point of the float and be sure it moves freely without binding, adjust pin retainers for alignment if necessary.

The best answer so far is from Dan Treace. I would ditch the Grose jet and replace it with a correct valve like the one made by Scott Conger. Many of the replacement NH float valves made and sold in recent decades have too small an opening (.100"), which restricts flow and results in fuel starvation. I believe the correct opening is .125"

Correct float level in any carburetor will not cause fuel starvation... If you're low on gas in the tank, the engine will stutter and stop running...... The grose-jet valve appear to sitting too high for the reason of double gaskets during assembly........ The float adjustment is with the Tang that's on the float. Just simply compress that Tang from its present position to obtain the 15/64 inch ( 1/4" ) float setting per Ford diagram.

The gross jet is sitting to high. When in normal position, there is very little hex to get a wrench on. I suspect the previous tinkerer added extra washers to keep the hex high enough to install. Thus loosing the float adjustment range.
Gross jetts are notorious for varnishing up & sticking. Plus the inlet hole is too small. Get rid of that gross jet & get a hi flow viaton needle & seat.

With the proper float setting, it will give enough time for gas passage into the carburetor for a continuous steady service .... If varnishing and sticking is a problem, the whole gas delivery system has to be cleaned due to dirt, old gas, neglect, .... no matter what diameter inlet valve is used, either Ford or other supply for the Model T Ford, NH carburetor.

Correct float level in any carburetor will not cause fuel starvation...

...and correct float level depends on sufficient flow from the valve. Restricted flow through the valve will not maintain correct float level. Fuel starvation comes from insufficient flow. Trash obstructions, a plugged tank vent, vapor lock, and a deficient float valve can all cause insufficient flow.

Correct float level is only to set a shut-off valve. As the engine uses fuel, the float will lower opening the valve. At the end of the day after pulling into the garage I leave the engine running, shut the fuel off at the carburetor and it runs for at least one minute before using up gas in the fuel bowl. I would think this shows that there's enough flow to keep the bowl filled while the gas valve is still open.

Greetings....
I had the Viton needle sticking in a NH. I used a dremel with a polish tip and some mag/chrome polish to get the Viton needle to slide freely so as to be close and open without issue. Don't polish the Viton tip, just the shaft of the needle.
It worked for me and stopped it from overflowing and dripping..... just an idea.

Look at the carburetor cross view and notice that little tunnel that goes up alongside to the two small holes that straddle the throttle butterfly, one keeps gas flowing for an idle position.

They are always overlooked and usually a problem for most "do it yourself" model T owners.

A single backfire can plug the lower end.

They are always cleaned when a carburetor is professionally restored.

Conrad ..... How are you doing with the NH carb re-build so far ?

All three of my T's have NH Carburetors. I have not had good luck with Viton tipped needles. There must be an additive in California that attacks the tip. Too bad. It seems like a real good idea. I wish someone would make a needle and seat that duplicates Fords original design.

I wish someone would make a needle and seat that duplicates Fords original design.

Have you tried the Conger version?

Thanks everyone for the advice. I did find that the new gasket that came in the kit was about 3X thicker than the original gasket. I was able to get the float adjusted and will give it a shot.

I read the initial fuel mixture adjustment should be out about 3/4 turn. Is that what you normally use? When I took it apart it was about 2 complete turns and since the float was set way too high it would need a little extra I would think but since it is now correct I think it would be less. What are your thoughts on that? Start with 3/4 turns out or do you have a different suggestion on initial settings?

I am going to try to talk him into pulling the tank and flushing it out the fuel in the carb smelled really bad and sure do not need stuff getting into the carb. I will follow up with an update when finished.

Sounds like good progress.. as far as the initial mixture, a turn and a half to two turns would be okay for starting, but you'll find that once the engine warms up the mixture would have to be leaned out to run better..... Besides flushing out that old gas, you may want to check the sediment bowl screen for crud restricting flow and also the pipe from the sediment bowl to the carburetor may need to be replaced which is easy. Keep up the good work !!