Tilotson Carb Adjustment

[MrMarty51]

A pic of looking into the main jet passage.

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I did find that the ears on the manifold flange of the carb were severely pulled. I sanded the flange back to flat but by the time I got done mowing the yard and boulevards I just was not up to the task of putting the carb back on and seeing if that will make a difference.

[MrMarty51]

Got back home Sunday afternoon.
Yesterday, Monday afternoon, installed the carb. Didnt seem to change a thing as to how the needle is adjusted, about 1/8th of a turn out is at its best.
I am wondering if this has the proper needle installed. Today, during day light hours, I will get out the micrometer/caliper and do some measuring with some pics and post them in the forum. Might be something someone can see in the measurements.
The only other thing I can see that would cause such issues would be if some PO had over tightened the needle and distorted the seating area of the seat.
Anyone have any other ideas as to why it would run its best at about 1/8th of a turn out ?

[MrMarty51]

Looking for a carburetor body with the proper high speed needle.
Looking in Mutts page I see the 1957 Model B Hummer requires the MT-43B carburetor.
Would anyone have such an item that they would be willing to part with ?
The float is partially pressed in on one side so one of those would also be nice.

https://www.harleyhummerclub.org/restore/chapter64/

[Mutt]

what carb do you currently have? I have new needles and floats

[MrMarty51]

what carb do you currently have? I have new needles and floats

Carburetor is stamped MT16A
I will try to get some pics with measurements of the jet needle that is in the carb.
I had at one time measured the in and out throats of this carb and I believe that it may be slightly larger than the original carb. Been a while back, and, it was just slightly larger, a 1/16th of an inch or so.

[Mutt]

MT16A is a Cushman carb, Same size venturi (5/8") as the MT43A & B. They work fine, just need to have the correct throttle lever and such

[MrMarty51]

MT16A is a Cushman carb, Same size venturi (5/8") as the MT43A & B. They work fine, just need to have the correct throttle lever and such

It seems to be all set up correctly, throttle, air filter and such.
Would this being a different carb model made for the cushman have a bearing on why the needle is only 1/8th or so of a turn from being seated ?
With the engine revved it sounds super good and revs very nicely.
The mounting flange was pulled on the ends and I filed them back to flat, maybe I now should give it the up hill pull and see what the plug would now look like.
I just have a fear of burning a piston.

[MrMarty51]

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Measured 0.413"
That is the measurements of the needle that is currently in this carb. I dont see how it could be wrong, but, I have been wrong before.

[Mutt]

the 48 and the 43 use the same needles

[MrMarty51]

The uphill, across the Yellowstone bridge run.
Starting speed at the bottom of the hill was 30 GPS MPH, throttle wide open, there was a bit of a head wind at about eight to ten MPH and got to the other end of the bridge traveling about 22 MPH.
Pulled into the parking area and shut down the engine, pulled the sparking plug for the inspection.

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The color isnt too bad but the main jet needle is screwed almost all of the way in.
After installing the plug, hooking the plug wire back to the plug, the engine would not start.
A little throttle, no go.
Tried some choke, no go, 1/2 choke, no go, more full choke with some throttle, no go, no choke and wide open throttle and still not even a pop.
Pushed the bike out onto the highway 59 North but I was south bound. One car at the top of the hill coming My way, maybe a mile away.
Coasted to the bottom of the hill to My turn off, pulled in the clutch after making the corner, into second gear, popped the clutch, engine turned over maybe a dozen times then popped off. Rode it the one more block home and parked it in the yard.
Not sure what was up, why it would not start. It didnt seem to have the compression like it should, shoved through mighty easy like. Maybe over heated some ? ? ? ?