Part 2 - Install Jet Kit & Set Air Fuel Mixture
[Post '98 Model Years (Single Carb)]
After much research I knew upfront when I changed my intake, the
overall balance required for optimum air:fuel burn would shift -- probably
dramatically. I was already running chopped factory pipes
. And, the open
intake was definitely enough to throw things off.
As part of my research, I found that the folks whose experience & opinion I
found highly credible were saying pretty much the same thing [here's a clue,
Scooby]: 142 Main, Needle Clip on the 4th Notch Down, Air Fuel 3 turns out
With that in mind, I ordered the Dynojet DJ1197
The kit came with:
- DJ122 (Main Jet)
- DJ126 (Main Jet)
- DJ130 (Main Jet)
- Fuel Needle
- Adjusting Washer
- Mixture Screw Tool
So, where the hell is my 142?
OK, so I wasn't actually pissed off. I knew up front I was going to have to come by the
142 main somewhere else. That's where Jets 'r Us
came in. For only $6.49 + Shipping
& Handling they'll sell you just about ANYTHING you could need.
It's worth mentioning early on, Yes
-- I had a full tank of gas. Yes
, the tank has
to come off. Yes
, I should have stopped screwing this part up already. No
I don't learn very quickly. On the up-side -- this can be done without completely
removing the carb. Ideal, probably not. But, my personal skill level leads me
to believe that the less I take apart - the less likely I'll screw up the reassembly.
Source & Reference: VLX Service Manual (From Sticky - This Forum)
5-0 Fuel System
5-11 Carburetor Removal
This is the schematic breakdown of the carb from the manual:
Step 1: Remove the Carb.
A. Loosen the drain screw to get fuel out of the float chamber.
B. Loosen the carburetor band screws. They are easily accessible
from the top of the frame.
C. Disconnect the carburetor.
Step 2: Remove the Chamber Cover.
A. Remove the 4 screws on the top of the carb.
B. Gently remove the chamber cover, spring & vacuum piston assembly.
* The screws, in my opinion, are pretty soft-headed for how tight they were. Don't be dumb.
** Be gentle with the vacuum piston. It seats in a specific way, and even a minor
tear or puncture will piss you off later.
Step 3: Remove the Float Chamber.
A. Remove the 4 screws attaching the float chamber at the bottom of the carb.
B. Since the carb is still attached, gently lift the float, and rotate the float chamber out of the way.
Step 4: Install New Parts.
A. With a flathead screwdriver, gently remove the old main jet & install the new one.
It's brass. Don't be a gorilla.
B. Using a philips head screwdriver, gently turn the plastic holder to
release the jet needle from the piston.
C. Set the clip on the new jet needle to the 4th slot down.
D. It may just be me, but I could not get the plastic holder reseated until
I clipped the top two notches off. I almost expected to clip one.
E. Install the washer that came with the jet kit onto the top of the jet
needle, above the clip.
F. Place the needle assembly back into the piston & install the holder, again
using a philips head screwdriver to turn it back into the locked position.
G. Reassemble the chamber, note the diafragm is "keyed" so that a small
portion of the diafragm fits into a notch on the carb body. Be careful. Take your time.
H. Reattach the float chamber.
I. Reattach the carb & tighten the band screws.
Here's sort of a half-assed cutaway I cobbled together...
Step 5: Adjust Air:Fuel mixing screw.
A. Using the "special tool" which came with the jet kit, turn the Air:Fuel
screw clockwise until it is seated. It is on the bottom, rear of the carb as you face
the bike from the carb-side of the bike.
B. Turn the tool counter-clockwise three full turns.
* My air:fuel tool had to be "bench-modified". It did not form a good fit to
the screw. The screw is shaped like a "D". And, I had to bend the tool a little bit to get it to "bite" properly.
Now, put the tank back on. Ride it out.
I hope this helps!