Choke Arm Repair???
 

The short silver choke arm on my DLE 55 came off of the brass stud a while back. It was a little loose from the factory, but this being my first gasser I did not realize that was a problem. The choke arm appeared to be a press fit from the factory so I pressed it back on and used a small screw driver to roll the edges of the brass stud back down onto the steel arm. This repair has worked for the majority of the summer, but it came off again last weekend at a flyin. Last night I was getting ready to press it back on again and use a center punch and a small hammer to really try and press the brass against the arm and then I had second thoughts. I decided I should see if anyone here has a better fix that will not potentially damage the carb. Will using a center punch and going around the edge of the brass stud slightly deforming it against the steel arm work, or is there a better way to do this.

Thanks

RE: Choke Arm Repair???
 

Easier and longer lasting to just buy an after market arm from Valley View RC that uses a set screw to retain it.

RE: Choke Arm Repair???
 

Drill and tap the end of the choke shaft for a 4-40 screw, use the screw and a washer to hold the choke arm on. You'll also need to file the end down slightly below the thickness of the arm. The other way is to install an accessory arm like one of these;

http://www.valleyviewrc.com/estore/m...-43-17_402.png

RE: Choke Arm Repair???
 

Thanks guys, I knew there was a better way. Those arm adapters look great as they may also take care of a geometry problem I was having with the linkage.

RE: Choke Arm Repair???
 

Another approach is to use the nylon arm from the nose wheel of a tri gear steering assembly, and secure it with its' setscrew. I would not use this on the throttle, but I don't see a problem using the nylon arm on the choke. Comments anyone?

Richard/Club Saito #635

RE: Choke Arm Repair???
 

I do that very thing on throttles sometimes too. Once every thing is set as far as throttle setup/geometry, I then put a drop of Loctite on the throttle shaft at the collar for the arm to make sure nothing moves and/or loosens up later. You have to be very careful the Loctite does not run down the shaft where it enters the carb however.

I have later taken the linkage apart on carbs I set up this way, and had to use a little heat and pliers to get the throttle arm off. So I don't worry about them ever coming loose in flight....

AV8TOR

RE: Choke Arm Repair???
 

Here's another choice in replacement arms;

http://www.troybuiltmodels.com/items/TBMCARBARMSL.html
http://www.troybuiltmodels.com/ns/im...SL_400x300.jpg

RE: Choke Arm Repair???
 

Those are nice arms, but they charge "an arm and a leg" for them!! ;)

AV8TOR

RE: Choke Arm Repair???
 

Yeah, a whopping $2.96 LESS![8D]

VVRC=$19.95
TBM= $16.99

RE: Choke Arm Repair???
 

something like this will do i think,and cost only a fraction.... [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000396387&I=LXD847&P=K]throttle arm[/link] ,[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD849&P=M]or this one [/link] (even cheaper)

RE: Choke Arm Repair???
 

piece of 1/16 sheet brass soldered onto the end of the shaft..customize the length for your application...2-56 DuBro link on the end...

RE: Choke Arm Repair???
 

Yep, done that too...

AV8TOR

RE: Choke Arm Repair???
 

We'll just call it "off the shelf" modeling specialists. If it hasn't been made and released for common consumption it cannot be done. To make it more specialized, whatever it is has to be marketed for under $2.95 to have serious consideration.

RE: Choke Arm Repair???
 

:D:eek:

RE: Choke Arm Repair???
 

RC...do you think many folks even know how to solder...It is a good way as any though. Capt,n http://www.rcuniverse.com/forum/js/f...wink_smile.gif

RE: Choke Arm Repair???
 

I drill and tap for the 4-40 bolt every time I’m using servo to operate the choke. It’s easy to drill on the lathe but I’m sure can be done without one. Take very good care of the choke plate screw if you have to remove it to put it in the lathe. I was always wondered if that screw can be re-used or should always be replaced but so far the red loctite is keeping secure.

RE: Choke Arm Repair???
 

You can use a piece of alum plate, about 1/16" thick. Cut it to the desired choke arm shape. Then drill the shaft hole first and then use the Dremel tool to shape the hole to fit the shaft. Drill a 1/16" small hole at the other side for linkage. Have been done that for all my gasser engines, whenever the stock arm does not provide the correct orientation, length, or anchor for linkage hardware.

RE: Choke Arm Repair???
 

I made my own with some 1/4" plate aluminum and some set screws:

http://i960.photobucket.com/albums/a.../Planes012.jpg

To get a better bite on the shaft I offset the set screw so that the threads are what bites into the throttle and choke shaft which by design puts more force on the female threads to help them from backing out and acts like splines to keep them aligned. The only specialized tool I used to make these was a band saw, but it was just a 3 wheel job I have $15 into from a garage sale... The rest was just drilling and taping.

RE: Choke Arm Repair???
 

Very nice, the off set.... set screw idea, I can use in other projects. Thanks

Tim

RE: Choke Arm Repair???
 

great thread/I installed my throttle on my dle 30 and the screw from the wlbro carb magically fell on the floor and disappeared..who says gremlins dont exist.I lokked at other screws and while one in fact seemed to fit I was not trusting it and imagined the worst case scenario flying with it.theres a lot of cheap and effective ways posted to avoid problems.

what I did ,however is go to my local toro dealer.I figured he works on walbros and might have the screw.what a wonderful suprise.he throws away the entire carb when our friend ethonal eats the plastic parts.he said wait a sec.coupleminutes later he came to the front desk with an entire walbro carb and simply gave it to me FREE!! yeah free. I bet if you are nice to such a dealer he may have a carb laying around he plans to throw away and might just hand it toyou.I did explain my situation and he does fix our field mowers and my generator and personal lawn equipment.but I know he would have given it to me even if I was a total stranger.

when I put in the screw I did add a drop of blue medium loc-tite//I dont want to spend 16 or 19 dollars for a snodized carb arm but then I wouldnt knock anyone who does given the huge investment in the plane..16.00 ofexpense on a 1500 dollar aircraft is cheap if it gives you peace of mind.

RE: Choke Arm Repair???
 

the free carb wasnt worth fixing just so we understand it wasnt a good one .but the screw was attached..for him working on a carb eaten up by ethanol its easier to discard.and that particular sat.he just had worked on a engine..I am sure everyone understood what I meant just wanted to make sure ..but it is a good place to get a needed original screw.

RE: Choke Arm Repair???
 

What was eaten up by the ethanol in the gas? Previous expert comment said that only the pump diaphragm is affected if it is the older black rubber. Newer tan or blue diaphragms seem to hold up fine. Seems it is typical shop practice to throw the carb away and charge the customer for a new carb than simply put in a new diaphragm for less than five bucks. I have picked up quite a few trimmers and blowers than only need a new diaphragm to run just fine. :D Some newer trimmers an d blowers don't have both hi and low carb adjust screws that are needed for our use [:o]

Thanks.

Richard/Club Saito #635

RE: Choke Arm Repair???
 

Well, the experts in this forum will have you believe there is absolutely nothing in the gas that will harm a carb, but I have most definitely not found this to be true. I don't know if it is ethanol, or other additives, but I have seen more examples of fuel caused damage than I can count. I buy large lots of used/discarded yard machines in the Tucson, Arizona area. Usually about 70 or so machines at a time. I then pick the engines I want to save to convert to airplane engines, and repair most of the rest of the machines to sell. Fully 90% + of the machines have carb and/or fuel line problems. Carb diaphrams "stiff as a board", gummed up carbs, blocked fuel pasages, fuel lines either so hard and brittle they break or conversely, disintegrated into a gummy like substance, etc. I buy carb diaphrams in lots of 40 at a time, and fuel line in 50 foot rolls.

In my gas powered airplanes, I have had diaphrams go bad in only 4 to 6 weeks! My brother has encountered the same difficulties, as have numerous of our flying buddies. While we were having these problems, it didn't seem to matter whether we stored the airplanes with the fuel system wet, or dry. The diaphrams in the carbs went bad anyway. Now, I use a "Storage Fuel" of Coleman fuel mixed at 20:1 with Pennzoil, and a dash of STA-BIL for good measure. I run the engine on this when done flying, and then leave the fuel in the tank for storage. This has solved the repeated problems we were having with our fuel systems. Note that this fuel IS NOT FOR FLYING, ONLY FOR STORAGE. Using this system, I have had engines sit for 1.5 years and work perfectly afterwards.

Just my experiences guys, even though they run contrary to popular advice here in the forum.... (Sorry to "rant on" off topic too!)


AV8TOR