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"Cox Tee Dee .010"



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Tee Dee & Medallion Venturi replacement

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Tee Dee & Medallion Venturi replacement

Post  RK Flyer on Mon Mar 30, 2015 1:47 pm

I am having some problems with my 049 Tee Dee & Medallion starting. On the tee Dee I know I have a cracked Venturi & need to replace it. Do I need a special tool to take it apart?

I am also using a old "Perfect" wedge Tank for both engines and I am not sure if it might be part of the problem. I am using the top tube for the fill & the bottom for over flow & the center tube to feed the engine, does this sound right? Both engines run on prime then stop.
Any tips will help will help! RK Flyer
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Re: Tee Dee & Medallion Venturi replacement

Post  RK Flyer on Tue Mar 31, 2015 2:22 pm

Thanks for the "Help". 52 views 0 reply's.

I forgot to say that I did do a search for any info yesterday but I sill wasnt sure about what to do or if I could do it myself so
I'll just send it off to EX and have it done.

RK Flyer Huh...
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Re: Tee Dee & Medallion Venturi replacement

Post  fredvon4 on Tue Mar 31, 2015 2:59 pm

I have been using bladder tanks so long I do not know the exact answer to the wedge tank...but I will give it a shot in a sec..

As you can see the TeeDee and Medallion are slightly different plastic carb bodies but both have the same removal issue

NOTE while you have the TEEDEE apart remove the needle and make sure the spray spigot holes are clear of any crud (inside the perimeter of the venturi and the NVA body)

on the TeeDee first remove the propeller, use the cox tool and turn the collet behind the drive plate counterclockwise, this will force the drive plate off the crank shaft and leave you with the plastic carb body to remove.

The cox tool sux for this (too fat and usually requires cyl removal first) so I use a thin wrench from an old skool ignition too set to unscrew the aluminum venturi and NVA set. Many times you can use the NVA to start to loosen the venturi and then unscrew by finger...Do Not Use pliers (they work well) but the Cox loving purists here and elsewhere will burn you at the stake!

Now if you are lucky you can slightly twist the carb body back and forth a bit and it would slip off the front of the crank case... but on a well used older engine you may have to soak a bit ( Hoppes #9, old fuel, 71% or 91% pharmacy alcohol, dish soap, antifreeze, etc) and add some heat (oven, crock pot, hairdryer, heat gun) to loosen the gummed up old castor oil

Replacement carb bodies are usually for sale including tough aluminum ones (not worth the money in my opinion)

TeeDee engines are intended for high performance and are real picky on fuel delivery as they seldom have enough suction to run well from a hard tank unless it is pressurized. The medallion on the other hand was designed for the sport flier and is much easier to start and needle

Store bought fuel tanks are notorious for crud inside, leaks and improper plumbing. First flush it a lot with isopropyl alcohol and a bulb/syringe looking for bits of crud. Plug any two of the three pipes and submerge in water pumping air in by bulb or syringe and look for bubbles. If good flush with alcohol or fuel and set it up so the feed line is right at same height as the NVA fuel inlet. close needle and top off the tank. Open the needle to see fuel flow from the full tank to the NVA letting you know you have gravity flow.

From there you should be able to start and get a decent bench needle setting

I am sure others here with more hard tank tips will respond... 52 views does not mean 52 different folks...the 6 or 7 members who know this stuff may not have logged on yet (working, flying, mowing the friggin grass...yada yada)

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Re: Tee Dee & Medallion Venturi replacement

Post  TDbandit on Tue Mar 31, 2015 3:09 pm

fredvon4 beat me to it
He's exackly right and to add to it when you remove the drive plate there is a small steel thrust washer behind it don't loose it and don't forget to reinstall it when you reassemble the engine and when you re-install the venturi do not over tighten it. Over tightening is one of the leading causes for the carb body to split.
(Bandit)
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Re: Tee Dee & Medallion Venturi replacement

Post  gcb on Wed Apr 01, 2015 4:37 pm

RK Flyer wrote: ...I am also using a old "Perfect" wedge Tank for both engines and I am not sure if it might be part of the problem. I am using the top tube for the fill & the bottom for over flow & the center tube to feed the engine, does this sound right? Both engines run on prime then stop.
Any tips will help will help! RK Flyer


If you have completed the cleaning and pressure process on the "Perfect" tank successfully and are still having problems you might check the pickup tube in the tank. You did not define "old" which could mean used and sitting around or unused. BTW many of the old Perfect tanks are made y Brodak. Brass tubing that has been exposed to fuel, and especially if fuel was left in it, can get pin holes from corrosion. Check by filling the tank and extracting its contents with the tank held with the pickup line held vertical. If it doesn't empty completely, you have a leak.

The engine part has been covered very well. You can temporarily repair the carb body with epoxy. Scuff up the nylon around the carb and wrap some thin copper wire around it. Then apply epoxy. Also check that the pressure fitting on the crankcase has not been drilled. If it has, you must run it on pressure or plug it.

Good luck.

George
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