Drilling jet procedure

How do you guys prefer to drill jets? Was looking at Loudhvx's TK22 site about drilling jets. He makes reference to the drill being put in a vice, but no mention on how you hold onto the jet?

I have a baby drill press at home I am hoping will be able to chuck up the tiny bits required... I'm guessing that would be much more acurate than doing it by hand.

When i did mine i just held the jet in my fingers. The amount of material that is being removed is such a small amount it shouldn't be a problem.

The way I do it is pick up the phone and call Rob at Z1E and order jets.
I just got four new jets for $7.00 it ain't worth the trouble to me.

i agree on buying before drilling, but pilots are not available and the jury seems somewhat out yet on using Keihin jets in place of the TK jets.

zukdave wrote: The way I do it is pick up the phone and call Rob at Z1E and order jets.
I just got four new jets for $7.00 it ain't worth the trouble to me.

That's great. I'll pay you to do that for me. I need some 34 and 37 pilots for a TK22.

Andy, you can use Keihin mains.

Make sure the drill is moving at about 1 or 2 revolutions per second. I don't see too many drill presses that go that slow. Look at the drill I use on my site.

I just hold the jet lightly in my fingers. The major advantage to that is you can gauge the torque. If it seems to bind or something is wrong, you can just let go. I've never even used oil while drilling, but it may be a good idea. With the pilots, the factory jets are sometimes not drilled perfectly straight so don't be alarmed if it seems to go off-center. That's another reason to use your fingers. If you mount it rigidly, you may be bending the bit.

Take time to find the orifice with the drill before pressing too hard. Look at the diagram I posted about how the inside of the jet is constructed, so you know what to expect and to know how far you will be reaching in with the bit.

BTW, why do you think you need to drill the pilot? Have you tried shimming the factory needle first? That is always the first thing to try since it can be undone. But make sure to see my site about how to shim the needle properly. Look for .6mm shims washers as the first attempt.

If you're going to drill jets, let the drill pull itself through. It only takes a second. I hold the jet on my hand and hold as it drills through.
Never use a press.
Steve

Thanks for the info guys. I was hoping to avoid the purchase of another drill if I have something already that will work.
So, my reasoning for drilling jets initially was because I wanted to do pods. Also, I have a ton of extra jets laying around that I never use, so I figured to do that instead of buying new ones.

So, my TK22 saga the past 2 months is as follows:
1. Bought excellent parts 550LTD. Swapped motor into my daily rider (used daily rider carbs). - was going to do pods, but had odd issues with richness with stock setup. Found fuel level too high in the carbs. Hopefully this was the issue, haven't tested yet.
2. Figured I'd get the parts bike running, or at a minimum, get the carbs cleaned and set up for pods, so I could maybe swap carb sets back and forth on my daily rider while adjusting jetting. Carbs were cleaned and set up (stock), but when installed on daily rider, showed major lean issues at low throttle position. Plan was to get micro drill bits to gauge the jets (rebuild kit ones installed in parts carb) to see if they were potential POS knock offs. Having trouble finding a kit that has bits small enough to gauge the 92 main and 32 pilot though.

So, in the end, I'd like to have the daily rider running well on pods, if not possible, leave with stock airbox and the parts bike running with either the pods or stock box (depending on what daily rider ends up as) so I can sell parts bike as a running parts bike.

Hope that all makes sense.

I got my micro drill set from either MSC ind supply or McMaster. Here is a picture of the notes from my build 7 years ago. I have pods with 4-1 yoshi header with tk carbs. Not sure about both jets being #32?? But thats what the notes say.

Harm, did you use the stock needle?

My cousin works at a machine shop - hoping he can snag me a bit that can verify if the jets I have in the parts carbs are correct. I won't even need to drill w it - just gauge the jet because I am not sure the PO didn't drill them

Yes, stock needle.

I stand corrected. The kit I bought (Lou recommended one) can gauge the main. I need an 81 or 82 to gauge the pilot. Also was going to gauge the little jet/orifice that feeds air to the main jet emulsifier as well.

The kit I recommend does the pilots and the main.

But before any drilling, I recommend you use a .6mm shim on the stock needles with all stock jets. I just jetted a KZ550A (same motor as the Ltd C model) with pods and a 4-into-1 Mac. We ended up with no changes except the needle was shimmed with .6mm washers (and the slide is shimmed accordingly to provide clearance for the washer. See my page on shimming the TK22). Even the air screws ended up at 1-1/4 out, which is basically the same as the factory setting.

That KZ550A starts easier and runs as smooth as any stock 550 I've ever ridden. The Mac was modified to be slightly quieter than how it originally came, but it's still way louder than the stock exhaust.

This is the best possible scenario. No drilling. No trusting of rebuild kit needles. No aftermarket jets. All changes can be undone. And most importantly of all... no removing the carbs to make the change! It's all done from the top and you can even sit on the bike's seat while doing the changes. What could be better?