There is a small hole approx. 1/8" in dia in my G20's carb choke plate which makes choking a little difficult as the engine sucks air through it when the choke is closed making me have to use my thumb as an assist to help get fuel to the carb. Does this hole serve any real purpose or can I solder it shut.

Karol

Oops ....double post [&o]

Karol

I believe the hole is thre so enough air enters to allow engine to run untill you adjust the choke to keep engine running as it warms up. Just My guess. If you solder it...be sure the soldrer never comes loose. It may damage the engine! Capt,n

An engine needs three things to run; air, fuel, and spark. If you completely close off the carb with the choke plate you eliminate the most of air part. That's what the little hole is for.

I hear you all loud and clear and I don't want to seem like a disbelieving Thomas, but tell me why do most other choke plates not have a hole.

Karol

Even with the hole the engine will not run for more than a second or so with the choke closed, and I totally agree on the 'damage the engine' part Capt.

Karol

Put a piece of tape over it and see what happens, if you don't like it, remove the tape.

I don't plan to start second guessing you guys, plus what Capt,n alluded to scares me enough to leave well alone. Come to think of it, it really ain't that bad afterall to use the ole thumb to help out.

Karol

I have heard and read about people closing the hole, so I would say try the tape thing first.

Yes, you certainly can close the hole to make starting easer. You can solder, or even use J-B weld. You are far, far more likely to have the choke plate screw loosen up and be ingested than the solder or J-B weld. Clean the the plate well and don't let capt'n scare you. I doubt that he is speaking from experience of doing this.

As for other engines, my 3W-50's have a small semicircular opening (like a hole drilled right on the edge) on the edge of the choke plate, which I'm sure functions to let some air in.
Sam

I soldered one on a Burelli 46 that was hard to choke and it choked MUCH BETTER...
The JB Weld might be the way to go....

If its a hole put a bolt in and locknut it, then cut off the extra length of bolt and don't clean up the cut thread, leave it crimped.

Mike

How about a rivet...it may work also. Most times JB weld works...but I have seen it not work also. The preperation was perfect. Maybe the quality of the stuff varies...who knows. Capt,n OH...Wings-RCU .....I got a lot of eperience!!!! Should I question your,s or anyone else?[:-]

Just solider it shut. The engine will choke much better. The choke it until it pops and then open the choke to start drill will still work just fine.

Captinjohn, I'm not questioning your RC experience but the experience you personally had when your engine ingested the solder that you used to seal the small hole in the choke plate. Have you actually had that happen and then damage your engine? If you have, then I stand corrected. Yes of course you can question my experience. That is why we contribute to these forms, for different ideas thoughts and personal experiences in our hobby. Warnings such as, be careful because the solder may come loose and damage your engine are much more valuable when actually substantiated or discounted by experience. Mine is, I have never had or personally seen anyone who had an engine destroyed when the choke plate hole is soldered closed.

I use a small piece of copper wire of diameter that just passes through the hole. Crimp it hard so that it will not come loose by itself. Then solder it to the plate, on both sides. Never have a problem with this method, over 4 gas engines.

I think the only way the solder would be a problem would be if you made a cold joint. Since the piece isn't sensitive to heat (it is in an engine after all) just make sure you get the joint nice and warm.

I say a engine needs 4 things to run...Air,fuel, spark at right time and compression! Capt,n

Not to argue, but I don't think it does need compression. It will run better with it but I bet it would run without it, not well though. This is convoluted I know, but years ago there was a UK show "The Secret Lives of Machines" and to show the power of gasoline the guy took a 2 foot piece of pipe that a soup can just fit in, mounted a spark plug on the end cap to make a canon or a single cylinder engine. First he poured in a spoonful of black powder, dropped the soup can down the pipe, then hit the spark, the can flew out about 10 feet. He took a spoonful of gas, poured it in, dropped a soup can in, after a couple of seconds he hit the spark, the can went about 200 feet. It didn't have any compression, but it worked, so I think if you built a engine that could squirt fuel into a camber with ambient pressure it would work.

From my number of posts you may question my experience, but I have soldered that hole shut on several carburetors including one on a gasoline RC airplane engine. In my opinion a good solder job would be the most secure of the options listed with tape being just plain a bad idea. The choke plate is going to be subjected to a spray of gas and air, even though it seems it is on the clean air side of the carb. I have never seen a carbureted engine that doesn't experience spray-back/stand-off at some combination of load and throttle opening. This gas mist being sprayed back onto the choke plate will dissolve the adhesive of most any tape, some quicker than others. I would not want even a piece of tape ingested by my engine.

As to why some carbs don't have that hole or slot. On those carbs the choke plate typically will be spring loaded shut and allowed to open some once the engine fires.

Hard to choke. Solder gets my vote, from personal experience.

Better yet....leave the hole in the choke plate. Give the engine a shot of prime, and it will start right up and stay runing, that is what the hole is for...DA. Capt,n

The soup can end of the pipe having the path of least resistance was the only lesson to be had in the powder/gas experiment. It was a directed blast the way it was set up. If a fuel/air mix has the correct ratios it will always ignite when provided an ignition source. The launch distance difference between the black powder and the gas was simply the difference in latent energy content for each fuel. Gas has more explosive energy than dynamite. No, you don't need compression to burn, but to extract the maximum energy from a motor fuel you do. Diesel uel is a great example. You can burn it but it performs best when under compression. Lots of other factors involved in using the stored energy of a fuel with compression only being a small part of it. The method the energy is channeled is a science of it's own.

Back to choke plates and holes. Note that choke plates without holes in them typically are not cut completely round. They will have a square cut section on one end to permit air to enter the carb.

My choke plate in question incorporates both of these features ..... go figure.

Karol

Y'all gotta to rember that very few of the carbs we use are for model use. Most are from a weedwacker/chainsaw. They both use pull starting . You can get several fast turns on each pull. The hole/notch is to keep Joe Suburb from flooding his weedwacker.