I mounted my new Tee Dee .049 on a test block and gave it a spin.

Hey Rusty,

Don't know if it's my situation alone or not, but I run a couple Tee Dee's pretty hard and they both will draw fuel and flood themselves even though I've got the tank level with the NV. I shut off their fuel using a light pair of scissor clamps I got from Radio Shack years ago. This lets me leave the NV alone while filling the tank.

I prime the engine, get a burst, then unclamp it and go again...usually works great.



Nitro's right, you'll love these things once you make friends with them !!!!

Rusty, you can bend that spring a little it might help hold the needle better. Try some teflon tape on the threads too. It might be a little hard to wrap nice but it might be worth a try if you have any around.

Rusty,
When I use a test stand, I install the tank so that the top of the tank is at or below the needle. This eliminates gravity feed. BTW, for folks who may not know, needle means spraybar hole, or in the case of a TD, the 3-hole sprinkler.

You can open the needle one turn from the closed position, put a finger over the air intake (TD) or choke tube (SureStart) and turn the prop over. IF you do not see it drawing fuel into the fuel tubing, open the needle another turn. When it pulls fuel, prime and start.

Kim, tell us about that fuel filter you are using. That's quite a test stand you have there.

George

Just as a footnote, medical hemostats work very well to temporarilly close off fuel lines.

I have medical hemostats in a variety of sizes with both straight and curved points. They are very useful many different modeling applications. A have a source that gives them to me for free after they are discarded at a hospital when they buy new replacements.

I moved the tank lower. I did try clamping it a couple of times, but I just need to get the hang of it. It doesn't have spring. I thought about teflon tape but didn't try it yet.
Thanks guys. I'll have better results soon.

gcb wrote:Rusty,
When I use a test stand, I install the tank so that the top of the tank is at or below the needle. This eliminates gravity feed. BTW, for folks who may not know, needle means spraybar hole, or in the case of a TD, the 3-hole sprinkler.

You can open the needle one turn from the closed position, put a finger over the air intake (TD) or choke tube (SureStart) and turn the prop over. IF you do not see it drawing fuel into the fuel tubing, open the needle another turn. When it pulls fuel, prime and start.

Kim, tell us about that fuel filter you are using. That's quite a test stand you have there.

George

Hey George...the fuel filter is made by Master Airscrew..#MA4500. "For use with 0.080 or 2.0mm fuel line." The note on the pack says that they are disposable and sealed together, but I've been pulling them apart, cleaning and shoving them back together for years without them separating on their own.

Thanks for the comment on my old test stand. It's an old "E-Z Just" stand that was given to me a long time ago, and keeps getting re-outfitted with new mounts to match the different engines I mess with (handy having a cabinet shop just up the road that tolerates me mooching hardwood scraps!)

I have a new JT test stand on the way from Omni models. Looks lilke a durable clamp style unit. Needed one for my bigger motors. Tired of lagging them to plywood and scuffing the mount holes on the motor. Its a metal stand so im gonna tool dip the ends of the jaws.

Several sets of hemostats in tge tool box. Indespensable item one you use them a few times

Sounds like a bad TD . Never had one hard to start. Old or new.
Dan

It might pay to check to see if the pressure tap has been drilled on it for tank pressure. Just use a fine wire to see if its been drilled.

jetpack wrote:It might pay to check to see if the pressure tap has been drilled on it for tank pressure. Just use a fine wire to see if its been drilled.

Mane but I doubt it because he probably would have seen fuel leaking out of it if somebody gad drilled it.

It's a good one, not tapped, I checked. And I was rushing. I just need to take my time and do it right. It has a very loose NV without the spring. I'll have a new NV soon and I'll backup and do it right. Rushing is a good way to get hurt with this thing too. I'll make a video to add to my collection.

RknRusty wrote:It's a good one, not tapped, I checked. And I was rushing. I just need to take my time and do it right. It has a very loose NV without the spring. I'll have a new NV soon and I'll backup and do it right. Rushing is a good way to get hurt with this thing too. I'll make a video to add to my collection.

Or you could use some fuel tubing in place of the spring.
Live chat?

The tubing should work in place of spring. Make sure holes in venturi are clean and open. Td's like nitro to run happy. Good luck,Dan

Kim wrote:...Thanks for the comment on my old test stand. It's an old "E-Z Just" stand that was given to me a long time ago, and keeps getting re-outfitted with new mounts to match the different engines I mess with (handy having a cabinet shop just up the road that tolerates me mooching hardwood scraps!)

Here's my old E-Z Just from the nineteen fifties...all original. I do have other, more modern test stands.

And yes, I've ran a few TD's on it.

George

I can see why people make their own test stands, because commercial ones are outrageously expensive!!! Well most are... I've seen them for over $70 on eBay!

MECOA sell Tatone Engine Test Stands for a very reasonable price. Available in two sizes, 0.049ci to .80ci and .30ci to 1.5ci

see http://www.mecoa.com/tatone/teststands/teststands.htm

And then of course there is Bernie's Universal Cox Engine Test Stand which is also great value but works for Cox engines only. Very well thought out and worth the money.
http://coxengines.ca/product.php?productid=303&cat=41&page=1

Cheers

Yeah...figure I'll get a couple more of Bernie's Engine Mounts...at least one to use to display assorted engines on my desk!

Rusty,

I hadn't started (or attempted to start!) a Cox engine in over 30 years, until I started my two TD .09's a while back.

My "test stand" is a piece of 2X4. I mounted a nylon TD engine mount on the end of the 2X4, then mounted the .09 on the engine mount. I built a plastic Sullivan 1oz tank, and mounted that to the side of the 2X4 with rubber bands. Hooked up the fuel line to the engine, put my finger over the venturi, and flipped the prop until I saw fuel pulling through the line to the venturi...maybe 4 or 5 flips. Hooked up the battery, and had it screaming in a few flips. They both ran good.

I don't have any pictures of it on a photo site, but will figure out how to post them.

The TD .049 is just a smaller version of the .09's...so they can't be that different to start. You might want to check the glow head. I had trouble with one of mine. I put a glow head conversion on it, and it fired right up.

Also, I completely disassembled and cleaned each one, before I attempted to start them. There's a good article on cleaning TD .049's on the "FlyingLines.org" at: http://flyinglines.org/bh.teedee.html

Allen

Thanks for the link, AT. I've been searching all over for an "Everything you want to know about Tee Dees" but haven't found anything but bits and pieces. That looks like a good thread for the basics. These look so much simpler than Bees, there may not be a lot that's not obvious. But looks are usually deceiving. I asked over at RCG but haven't gotten any answers. I figured there would surely be one at RCU.

I have gotten mine to start easily now. My problem was the fuel tank was mounted too low, and the venturi may be enlarged, I haven't looked under the screen. That and a loose NV, which I fixed with a fat piece of fuel tube. I have a new venturi and a fine thread NV coming soon. It's a big ol' clunk tank for a large plane. My mount sounds pretty much like yours now. She starts runs at 2 1/3 turns. When it's hot it cranks there too. It really is sensitive to the fuel position. It won't pull it up from any lower than the carb, and it floods if the fuel is any higher.
But when it's all level it's a really happy baby. I wish I had a tach. That's for Christmas.

Rusty,

I asked some questions of Barrie, and he was really helpful. I'm sure he'd answer any questions you have.

My TD's didn't seem all that sensitive to where the fuel tank was...but I do have it (the outlet feed line) close to the center of the venturi. I started out there, after I read a bunch of different forums...

Allen

AT1984 wrote:Rusty,

I asked some questions of Barrie, and he was really helpful. I'm sure he'd answer any questions you have.

My TD's didn't seem all that sensitive to where the fuel tank was...but I do have it (the outlet feed line) close to the center of the venturi. I started out there, after I read a bunch of different forums...

Allen

I'm bad with names, is Barrie one of our members?
I had originally intended to disassemble and clean it before I ran it. But considering it came from fit90(Bob), I only opened it up as far as removing the piston. At the time my only concern was where the piston started to snug on the upstroke, about a 1/16" or maybe more before TDC. I know the #4 cylinder and piston are tapered, and the guys at RCG said it was okay. Plus it was sparkling and the crank was free spinning, so I put it together and ran it.

But after reading that page you linked me to, it says the piston should snug at 1/32" before the head deck, so I'm thinking I should de-varnish it before I put it on my plane. What do you think about that tight fit mine has? I cannot feel it when I turn it by the prop with compression. It feels just like a Bee, and my short runs may have loosened it up already. I'll probably buy another #4 set while they're still available. Bernie says the new type works just as good, but I'd rather have the real thing. I love having something new to explore.

I just came in from tinkering with it. I decided to measure where the piston begins to stiffen in the bore. I could only guesstimate the depth at 3/16" before TDC when it starts to stiffen. I got a better read on the protractor and that first point where you can feel it tightening is about 35° BTDC and it gets tighter as it progresses, but not so much that I can't push it all the way up to the head landing with just my fingers.

That's a lot tighter than that TD racing web page said(1/16"), but what he says fits the description of a new style non-tapered cylinder. I think mine's probably just right. BTW, there is almost zero slop in the ball socket and the rod moves perfectly free in all directions. This is a nice engine

I timed it on my 3/8oz tank. I have overlooked this in my plans for the Stuntman. I definitely will need a bigger one. It only ran 52 seconds on the 3/8 oz wedge tank. I'm going to need at least a 2 oz tank to keep it in the air for 4 or 5 minutes. That's a big tank to mount on a wing. How does this look for the job: http://www.brodak.com/shop_productdetail.php?ProductID=6356
Or maybe a round clunk tank may be better.