These KL / Taffy Mods intrigue me, tell me more

I've searched archives and found intructions on the KL mod but I was unable to find intructions on the Taffy mod (only lots of posts on results).

While I am familiar with all the parts of the carb they reference, I have neither the skill or tools to perform these mods. While I am reading the KL intructions, I'm just not picturing the procedures. So I am reluctant to start drilling out holes in my carb.

So correct me if I am wrong please. What I am gathering is the fuel squirt is way too long on the 99s. (I never timed mine but I seem to remember it being at least 3 seconds if not longer on my carb. That is with a full bowl, carb off and manual AP manipulation). I don't remember it actually hitting the carb slide though. So do I have to actually trim the rod? (My idle screw is all the in so the slide is pretty open already. Since I went to YZ timing a while ago, I have to have the idle set very high just to keep it running).

So am I reading correctly that you want to shorten the rod only if you need too? But won't that just delay the time the rod hits the diaphragm? See what I mean, I just am not understanding what is getting accomplished here.

So what you are doing here is drilling the AP cover out. Putting a screw through the cover that is adjustable. So you drill from the inside of cover out but you put the screw from the outside in? Is that correct?

Any one in CO actually perform these mods? If so, maybe I can talk you into giving me a hand.

On the 98 & 99 model the rod needs to be trimmed only if the squirt hits the slide. If it doesnt, no need to trim it. Taffy maintains it doesnt matter. Your choice. Anyway... trimming the arm will DELAY the squirt START. It does these soon as you twist the throttle the slide starts to lift with the needle. At the same time the actuating device starts rotating and the rod moves. The rod pushes on a diaphragm filled with gas. If you shorten the rod it contacts the diaphragm LATER, delaying the start of the squirt.

Now once the rod is moving, if you allow it to move all the way through its travel, it continually presses on the diaphragm creating the 'squirt' until its stops moving. What you have to do is stop the arm moving prematurely reducing the length of squirt. Here you have 2 options : The KL mod or the Taffy Mod.

The Taffy mod does the following: Firstly imagine an electical block connector..the thing you might use to connect two loose pieces of wire together. You need to extract ONE small metal tube from its plastic insulator. You now have a small metal tube with two screws tapped into it at right angles - the ones that squish the wires. You now should cut this in HALF with a hack saw so you are left with a short tube with one screw in it. (At least I had to do this)

Disassemble your carb and slip this tube over the rod and reassemble. Now use the screw to tighten the tube onto the rod. The objective is to use this a "stop" on the end of the tube/hole that the rod disappears into. You have to play around with the position. When you get the position right this will stop the travel of the rod prematurely, thus reducing your squirt duration to about .5 seconds instead of the 3 or so it has stock.

I hope this is clear.

use the Taff mod. It is not intrusive to the carb body.

OK Doug, Lets do this APJ "Taffy Mod". Jake and I got together last Sunday and greased the swing arms. Maybe we can get some CO guys together to tackle this APJ mod. What other '99WR400 guys in Colorado want to do this? Jake? Bryan? Ron?

Missle, thanks for the detailed message now I just need to get more familiar with the carb.

Count me in. I'd feel better if you guys were there to screw it up with me :)

Just let me know when and where. Fri or Sat works better for me as I have those days off.

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