Drilling jet procedure

Haha true.
I will play around before I drill at all. But what I'm getting at is the one carb set has aftermarket jets in it. I wanted a bit that is close to a 32 jet, which looks like an 81 or 82 drill bit, which the kit only goes from 61-80, so although The kit has the bits to drill, it doesn't have the bit to match the stock pilot. I want to verify that that the jets are in fact not drilled and are what they are stamped.

If they're air/bleed, I wouldn't F with them. If they are fuel, one step can be compensated with the screw.
Steve

Steve - I am assuming you are referring to the air screw? It is an air screw on the airbox side of the carb, so it meters the air.

Lou - This 550A you mention, would you say you were surprised that all you had to do was shim the needle? (also, do you recall how many shims you used?) In alot of the searches I did for pods and 550's w/ TK22, it seemed like the starting point was up a step or two for the mains, maybe 1 step for the pilots, 3rd clip from the top for the needle.

Based on my experience with these parts carbs I have (the ones with the rebuild kits in them) I have my doubts as to just how identical to stock the needles I have on the 2nd clip really are...

The smallest drill in my set is #81. Too big for the CV style pilots. I had to use it because a strand from a wire brush and my smallest guitar string wouldn't fit. These carbs have the fuel mixture screw in front of the carbs. That just meant I had to adjust them down but they worked better than stock. These bikes were jetted lean from the factory. I suspect you can drill your pilots but due to the unavailability of new jets it's a crap shoot.
Steve

agreed. Like I said, I was hoping to be able to get an #81 or #82 and stick it into the jet - if it was snug, it wasn't drilled out. If it's loose, then someone went McGuyver on it. I actually do have a handful of spare pilots that are plugged tight. I tried everything and can't get them opened up. But being the packrat I am, I still have them, so no harm no foul if I drill them. lol

That's what I'd do. Running a little rich isn't a big deal. You might be able to lean it out with the screw. I'm back to where I was two years ago now I have my new pistons in. She wants more juice. :woohoo:
Steve

Yes, I was surprised we could get away with a simple shimming with no drilling on the pilot.

Luckily, the TK22's are drilled with relatively large pilots (compared to many other types of carbs) which lets us use the 61-80 drill kit.

As long as none of your drill bits goes through the pilot, I think it's safe to assume the pilots are at 32, as I've never seen any smaller. But if all you are looking for is a gauge, and not an actual drill, just buy a guitar string and mic it to confirm the diameter. They are usually very consistent. Guitar center sells individual strings. A .012 string will fit in a 32 jet, .013 string will be very tight or not fit at all. If a .012 string fits, and your smallest drill bit does not, I would say the pilot is probably close enough to 32. Since you will need guitar strings for the shims, might as well get a few as gauges too. Even wound guitar strings work ok as rough gauges for the mains as they are surprisingly precise, but for the pilot, just get single plain strings, the material doesn't matter as long as it is some type of steel. For the shim, get a .028 bronze-wound string, or maybe stainless steel wound.

Good point Lou - never thought about using guitar strings and using the smallest bit my kit has - because one bit smaller (that I don't know) would be the stock diameter.

If the jets check out ok on these part carbs and there are no air leaks, I'll really be at a loss for why it falls on it's face when you open the throttle at all without choke. I would bet good money on the pilot circuits being clean, I know for a fact the mains were clean, fuel level correct and at least #1 needle was set at the proper clip position. It was stamped Y77 as well.

Also, Lou, I sent you a PM in regards to those vent hoses that run under the seat... I had them taken off for a while because they were just in the way while working on the carbs...but then I remembered the issues I had on 93 shadow that I had taken it's vent hose off - it was a special hose, with decreasing ID (same OD) vent that was about 3' long... must provide backpressure or something. Anyway, I took it off to clean the appearance up and it ran so rich I was fouling plugs. Put the vent hose back on (a week later and 101 carb cleanings) and it ran fine....

Have read more than a few times to not stick nothing in the jets and just blow them out with air and cleaner but I do like Steve's and Lou's ideas of gently using guitar stings ....... will go over my smooth bores with all three before I put em back on this time.

Y77 is an aftermarket needle. It is a replica of the 4D93 factory needle (non-U.S. models). If it's a poor replica it may be troublesome, but usually the stamped needles are ok. It's the needles with no stamp that are usually suspect. But if you wanted, you could compare the diameters with a very precise micrometer to compare it against a known factory needle. But only use a high quality mic for this. Cheaper ones are not good at measuring tapered surfaces.

If it's falling on it's face, off-idle, then it's not a screw adjustment issue.

The vent hoses do affect things, but really only at speed. It will only create a vacuum in the bowl if the hose end is in the air stream facing rearward or behind an object that is in the air stream, then that will definitely affect the mixture toward lean (and likewise, if the vent is facing into the air stream to create pressure, it will make it richer). Just make sure they run up under the tank/seat into a relatively protected area, and make sure both hoses are secured there (but not pinched).

True bowl vents are just to assure the air pressure in the bowl is atmospheric. If the hoses have some strange taper or otherwise control the pressure in the bowl to a non-atmospheric level, then it is not a vent, but some other active part of the carburetion. The TK22 bowl vents are just plain vents. You can take the hoses off at the TEE, and leave them open, but that just has more chance of getting dirt in there.

Thanks Lou. I did have them off at the tee when I was having my rich issue... Otherwise they normally are under the seat.

Yes, idled like a champ, pulled hard all though >1/4 throttle, but even when piping hot, if you pulled away from a stop you had a 30% chance of not killing it. Throw the choke on and life went on fine. If its not a screw adjustment issue or plugged pilot circuit, all thats left is needle issue, jet issue or fuel level issue, right? And I can confirm fuel level is within spec.

Lou I did not know you can't get new jets for the tk carbs.