Jet Kit 101 - Ivan's kit by B12Teuton

[mike]

Jet Kit 101 - Ivan's kit
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B12Teuton
(4/9/04 12:03 pm)
Jet Kit install; 101

 I had some anxiety about carb work for a long time. Even though I had done a jet kit before on a dirt bike, I was a little nervous about attacking this on. BUT in my usual "hit first, ask later" way, I went ahead and bounced out another project

This is Ivan's jet kit for the 2nd Gen B12S

Here goes:
First, take off the seat, tank, airbox lid etc. Sorry this pic is kinda dark. Too many toys and not enough room in the garage!


Next, grab the nifty sheet that Ivan's kids were nice enough to draw up  and drill twenty 3/8" holes in the airbox. Also pull out the snorkel.


Now remove the two bolts holding the airbox in place and loosen the 4 intake clamps on the carb boots. This will allow you to pull the airbox back slightly.


I had my hands full with the carbs wile I was taking them out, so I didn't get an action shot. Either way, you want to loosen and disconnect all the hoses and cables from the carbs.  The hardest part is the rear throttle cable. The choke cable (shown in my hand) as well as the front cable were fairly easy.


I used a surgical clamp to reach down and work the wires into the position required to disconnect them.  Now bring the carbs over to your work bench. Unless you drained the floats really well before, there will still be gasoline leaking out of the carbs when you lay them down, so have a good rag handy.


It's time to drill out those pesky plugs! Mark your drill bit with some tape to use for reference. I used a sliver of white duct tape 1/4" from the tip of the bit.
* be very careful as the plug is soft copper and drills out quite easy! If you blow through it, you mess up the mixture screw just behind it!


And there it is! Turn them clockwise all the way in until they are lightly seated and then back them out 3.5 to 4 turns.
Count as you turn them in. All 4 of mine were different in the stock position 2.5-3 turns out. Make sure you do all yours the same!
**note said surgical clamp


Once you've done all four, clean up really well, as you don't want any of the metal shavings to get into the carbs!
Now use a firm grip on a GOOD Phillips head screw driver and open the four screws holding the float bowl onto the bottom of the carb.
Open it up and see what ya got:


Now use an 8mm wrench and a large flat head screw driver to remove the OE 100 main jet:


Set it aside and grab you new 112.5 main and install it.


Repeat for the other three carbs.

You're about 1/2 way home


Once you have all four new mains in there and everything is closed back up, flip the whole thing over so you can work on the other side.


Remove the two large Phillips heads holding the cap in place.
Carefully lift the cap and set it and the long spring aside.

*Be very careful not to loose the tiny rubber o-ring that's sitting at about 3 o'clock in this pic!!
** also be very careful with the black rubber diaphragm that is now exposed. The slightest damage to this thing and you are screwed!
CAREFULLY pull the diaphragm away from the carb and pull the slide and needle out.


Now I employ my trusty (multi purpose) surgical clamp again to pull out the gray plastic retaining plug inside the slide.


You have to be VERY careful as there is a small spring under this plug that pushes down on the needle. This spring wants to fly, and if it does, you probably won't ever find it again!
So, now the rest is pretty easy. Under the spring there is the OE needle which has a clip on it. On top of that clip is a tiny washer. Under the clip is a fat little nylon donut. Transfer these two essentials onto the NEW needle and put everything back to where you found it!
(sorry, out of focus and a little dark)

It's a little tricky to get the the new needle back into the slide with everything in place, but by the time you do the 4th carb, it will be easy.
It is CRITICAL that you make sure the diaphragm is seated properly on top of the carb. It might seem as though the diaphragm is slightly too large for the space it needs to fit into. Just work it patiently and it will seat itself. If all else fails, I've heard people use some gasket glue to help keep it in place, but I'm not sure I would rock that approach.

Once you get all four done, do some cleaning and put them back in the bike! Make sure you clean off the boots that are on the airbox and intake manifold as they probably have lots of crap stuck to them that is just waiting to jump into your engine.

Keep your fingers crossed!