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Choking a US41?

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Old 10-03-2006 | 02:56 PM
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Default Choking a US41?

I have a US41 on a plane I'm restoring. Noticed the carb has no choke valve at all. Manual says to "choke" engine before starting. This engine is in a WWI wqrbird. Because of the way it is built there is no way to get a finger in to cover the throat. anyone got any ideas on what to possibly do or starting a US41 without a choke.

I got a fair bit of gas engine experience; but this is the first magneto engine I've had and the first with no choke.
Old 10-03-2006 | 03:15 PM
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Default RE: Choking a US41?

Wrap your hands as firmly around the carb as possible, lock your fingers together, and squeeze the daylights out of it.

An alternative is to change the carb to one with a choke plate in it.
Old 10-03-2006 | 03:24 PM
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Default RE: Choking a US41?

Jeesh, what an idiot (me) . I never thought of that. Must mean I'm working to hard.

Steve
Old 10-03-2006 | 05:31 PM
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Default RE: Choking a US41?

Which, the hands or the carb?
Old 10-03-2006 | 06:45 PM
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Default RE: Choking a US41?

seriously a tiny squirt bottle of fuel may do the job for you
go easy on this - just a light squirt
and get a BIG glove to make nice quick prop swing at low throttle NEVER high throttle .
It will likely take a few applications and false starts
If you are looking at fixing the problem for shere --- get a choke carb
Old 10-03-2006 | 07:24 PM
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Default RE: Choking a US41?

I use a velocity stack, and a cork on my Dr-1. Works pretty good.
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Old 10-04-2006 | 12:12 AM
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Default RE: Choking a US41?

I use a miller belt reduction setup on my starter - at 24V it takes about 15 seconds to start popping and start! Easier on the fingers and on the arthritic hands!

Phil
Old 10-04-2006 | 01:48 AM
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Default RE: Choking a US41?

Well someone beat me to my suggestion, two hands wrapped around the cylinder and squeezing hard. make believe you're choking a chicken.

or if you want to get creative a rubber or cork stopper on a stick will also work. only because you might have too much fun choking the chicken (trucker joke)
Old 10-04-2006 | 08:23 AM
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Default RE: Choking a US41?

Some how I think choking the cylinder to death will not work I have ordered a carb. There is not enough room for a velocity stack or to get anything in there to cover the hole; and because of its location and the way the nose was built I couldn't cut a hole in the side if I wanted to (which I don't). Using my starter on that flat prop hub is probably out also.
Old 10-04-2006 | 06:27 PM
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Default RE: Choking a US41?

You ever seen a choke plate on a 4-cycle glow engine? It's just a little flapper on a spring. You put a finger on the flapper plate and it closes off the carb.

Maybe you could do the same thing with your carb. Use the carb mounting screws to hold a little ring on the face of the carb. Rig up a little metal or balsa flapper on a hinge and put a piece of rubber on it to make a seal. Rig it to a servo and a linkage.

Crude paint image:

How rude goldberg is that?


Edit:
Silversurfer beat me too it. I was gona tell you the same thing. [sm=lol.gif]
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Old 10-04-2006 | 08:10 PM
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Default RE: Choking a US41?

I was hoping I knew Steve well enough that I could get away with it Without the alternative of the carb change I prolly would have to have been outrunning a bullet, tho.
Old 10-04-2006 | 08:13 PM
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Default RE: Choking a US41?

Good luck on trying to start that magneto engine by hand! I couldn't, even with the spring starter! After I got it warmed up by starting with the miller rig, it would start with the spring, but what the heck, I had the big starter so I removed the spring and clutch and saved almost 1/2 a lb.! Give some thought to converting to ignition and running a plastic tube from the edge of the cowl to the carb opening. Then you can give it a squirt with a bulb.

Phil
Old 10-06-2006 | 06:14 AM
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Default RE: Choking a US41?

Mine starts very easily with the spring starter. If one doesn't, it is best to check the magneto gap. I also have one running on CH Ignition and it hand starts easily. Causion on the intake tube: if it sets up a pressure differential against the diaphragm there will be other problems.

Have fun!

Bedford

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