Cox .051 Tee Dee cranksaft removal and replacement

To remove the crank from a Tee Dee, you must remove the backplate. I usually take a marker and mark the con rod so that when I'm reinstalling it I have it on the same way it was originally on the crank pin. This may or may not even matter just something I do. I remove the cylinder and take out the piston. I screw the cylinder hand tight back into the case. I use this to hold onto. Using the proper wrench for the Tee Dee, the one with the pin spanner unscrew the lock ring that holds the carb body on. This will force the drive plate off of the crank. Be careful not to lose the drive washer which could either be phenolic or stainless steel. It can easily fall off or be glued to the drive plate on the back of it. Unfortunately, the Killer Bee crank won't fit or work in the Tee Dee as that crank is designed for a reed valve engine. Is the original crank broken? Now is a good time to check the ball socket fit of the piston and reset if needed. Reassembling is just a matter of reversal of operations. Although putting the drive plate back on the crank can be problematic. They do make a tool for this although I made my own. I line the splines of the drive plate back onto the crank. I have a 5-40 allen screw which has a nut threaded onto it and I have a spacer with a washer placed against the drive plate. I screw allen screw into the crank until it bottoms then I proceed to back the nut and washer back into the drive plate. This presses the drive plate back onto the crank squarely. It can be very easy to place the drive plate on crooked. Ken

Is this not it?

http://www.ebay.com/itm/Cox-049-051-Medallion-Model-Airplane-Crankshaft-Engine-Crank-049-051-/390370583461?pt=Radio_Control_Parts_Accessories&hash=item5ae3e663a5#ht_1247wt_1108

microflitedude wrote:Is this not it?

http://www.ebay.com/itm/Cox-049-051-Medallion-Model-Airplane-Crankshaft-Engine-Crank-049-051-/390370583461?pt=Radio_Control_Parts_Accessories&hash=item5ae3e663a5#ht_1247wt_1108

That's a Medallion crank.

Below are our carb body installation instructions but they apply equally to the crank:

Carburetor body installation

• Unscrew needle valve
• Unscrew venturi
• Remove needle valve body & spring
• Remove backplate
• Remove cylinder
• Remove piston
• Stand crankcase upright, drive-plate facing upwards
• Insert prop screw as deep as possible
• Tap with hammer until drive-plate separates from crank
• Unscrew collet
• Wedge flat object between carb body and crankcase and twist. Use a plastic or wooden object and not a metal one to prevent scratches – A med-sized flat screwdriver with the tip taped over for instance is an option. (Carb body is pressed on, not screwed)
• Press in new carb body
• Re-assemble engine

For ease of dis-assembly / assembly we sell the following tools:

• Wrench
• Dis-assembly tool
• Assembly tool

RknRusty wrote:

microflitedude wrote:Is this not it?

http://www.ebay.com/itm/Cox-049-051-Medallion-Model-Airplane-Crankshaft-Engine-Crank-049-051-/390370583461?pt=Radio_Control_Parts_Accessories&hash=item5ae3e663a5#ht_1247wt_1108

That's a Medallion crank.

What's the difference?

The TD crank has more aggressive porting.

microflitedude wrote:

RknRusty wrote:

microflitedude wrote:Is this not it?

http://www.ebay.com/itm/Cox-049-051-Medallion-Model-Airplane-Crankshaft-Engine-Crank-049-051-/390370583461?pt=Radio_Control_Parts_Accessories&hash=item5ae3e663a5#ht_1247wt_1108

That's a Medallion crank.

What's the difference?

Medallions have a small round crank
Intake and tee dees have a large rectangular one.