Dellorto UA-19S Help

#1
I have a Del UA-19S that runs too rich black smoke and doesn't respond much to adjustments, the metering rod is a C1 and main jet is marked 06 see picture below, this carburetor came from Italy so I don't know what the application was. I am using this on a Tecumseh HS-50 similar application as a Rupp Black Widow, I have the metering rod set all the way forward I believe that is a lean setting, anyone know what the main jet size should be or have any idea what adjustments are available to fix it.

Thanks

Tony

Dell Jet 071418.JPG
 
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#3
I got it working properly, I took it apart and cleaned all the parts and passages there was a plugged hole, I can't believe it started on the first pull, I put in an adjustable high speed jet while I was at it.

Thanks

Tony
 
#5
Delray

When I was working on the ignition last week I moved the timing advance .045", I did get a couple of short rides in yesterday setting up the rotation stop and TC, running on the stock carburetor it pulled really well uphill. Last week the engine blew some oil out the crank case vent some got on the TC belt, when I first went out for a ride yesterday it felt like direct drive it lifted the front wheel for about 5 feet taking off, surprising how much low end torque it has for an engine with a modified cam. Tomorrow I will get it out for a long run now summer begins.

Tony
 
#7
I had the main jet from BWMS and made the rest of the parts, also made a less than 90 degree throttle cable tubing at the carb to clear the exhaust.

Rupp Del 071418 (1).JPG Rupp Del 071418 (2).JPG
 
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cfh

Well-Known Member
#9
i thought the slide and cable went on the other side of the bike?
also where did you get that air cleaner? what size is the opening?

 
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#10
cfh

I setup that Dellorto a little different than a conventional Rupp this way it's cleaner and easier to use, that's the nice thing about those carbs they are somewhat universal. I bought the filter off ebay awhile back, going by memory I believe the filter opening is about 1-5/8", I turned the aluminum adapter plate it has a nice radius lead in for smooth air flow. Something to be aware of the 90 degree throttle cable tubing at the carb is plated brass it doesn't bend much, when I tried to adjust the angle back to clear the exhaust that tubing broke off at the threads leading into the carb, I made one out of stainless tubing.

Tony

Tony
 
#12
The exhaust pipe "fasttony" is using is not the same as a factory B/W pipe. It does not have the bends in the same places, giving clearance for the carb to be in the OEM location. Looks like it will work just fine, but be careful that exhaust pipe gets very hot and can melt the plastic cable housing. It could cause the throttle cable to lock up from melted plastic. Just a precautionary note. I applaud anyone who does their own fab work.
 
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