the kinetic tfr project

I put a Dellorto 13.13 Carb on my TFR a few weeks ago. It was a little more difficult than I thought it would be because it is not a bolt-on operation. This is mainly because the throttle connections are different from the stock carb. here is a side by side comparison:

Stock Carb is at left / Dellorto 13.13 at right

I drew in the cable connections to illustrate the differences. The Dellorto requires more cable. I had initially modified the stock kinetic throttle cable to fit the Dellorto carb, but someting weird happened: When I started it up, it would seemingly rev up at random. Not good. It took a few cycles of the bike revving up uncontrollably and me hitting the kill switch before i realized what was going on. It was the throttle cable. It was too short and when I turned the handlebars to the left, it would pull open the carb. So I had to get a new longer throttle cable, cut it to length and re-install the carb.

Here is what should work for anyone else doing this:

1. Remove the right side panel
2. Remove the airbox
3. Remove the stock carb
4. Get (make) a new throttle (longer) cable
If I remember correctly, it has to be at about 52 inches. I think that there are a few places on-line that might sell them. I had to go to scooterworks and show them my old cable and they hooked me up with a longer one. I’m sure that you could find one somewhere else with a little research. The trick is to find one that has the right size connection to your throttle grip:

It took some doing to get the cable length right. I measured mine by hooking up the new throttle cable to the grip (you just have to unscrew the two screws that hold the throttle grip on the bar and pull it off the bar). Then I took the other end and hooked up the bent tube from the carb, eyeballed the gate travel distance, and cut the cable. For the end, I put a bead of solder to hold it in the carb.

UPDATE
As I have learned from some MRA and Moped army posts, the top cap from the kinetic’s old carb will work on the dellorto carb. that means you do not need to get a longer cable, just swap the assemblies on the carb that the cables hook into and screw the stock kinetic one on to the new dellorto.

5. Route cable as necessary from throttle through front fork

6. Assemble the end of the cable and carb gate
Feed the cable through the tube and the top assembly of the Dellorto Carb.

7. Assemble Carb and check the travel on the gate.
You will want to make sure that the cable is letting the gate close a hair past the idol screw and able to lift the gate all the way open

8. Remove that choke thingie
Now that you have committed to your new cable and carb, you will need to remove the thingie that holds down your stock choke lever:

Just unscrew the screw and it comes right off. The Dellorto choke operates differently and you won’t need it.

9. Route cable through subframe and reassemble carb for final time
Double check gate and cable length again.

10. Use an 8mm box wrench to tighten the clamp on the carb to the manifold
Make sure the carb is all the way on. Pull the choke down before you tighten all the way. You may need to rotate the carb to give the choke enough room to go down all the way.

11. Re-install airbox by tightening the clamp
12. Hook up fuel line by sliding the tube back on the banjo
13. turn fuel petcock to the “on” position

All done. My choke does not go all the way down once my side panels are on. It’s never really been an issue. My tfr starts right up without the choke. This causes me to believe that it is running a little rich, but oh well.

So I opened up the carb, but it probably didn’t do all that much. I don’t believe I will see any significant improvements until I open up the intake manifold. The intake manifold has some restriction inside of it that prevents more air/fule from coming in:

This photo was sent to me by another TFR modder and great guy, Steve Kames from GA. (thanks, Steve) It shows the inside of the intake manifold and the metal around the edges that can be bored out to allow more air and fuel into the chamber. You need a crankcase splitter first, though and that is a whole other story.

Here is what Steve has been up to: