You can take a peek at one of your needles.
Standard ones have 5D130 or 5D129 stamped onto them (at the top near the e clip).
This only takes 5 mins to check (3 bolts)...
See the Ivan's kit fitting guide Falcon has linked to for info on getting the needles out, you will be doing it with the carbs in place so will need to lift the front of the tank prop it up (or remove it completely but that's not necessary) and take the top off a carb. The second from left I found easiest - you only need to check one of them as the kit replaces all 4.
From memory the procedure is:
Remove front tank bolt.
Lift tank up and prop up high enough to give access to carb tops. Keep an eye on the fuel hoses at the rear of the tank as they can stretch a bit, you don't want them to split (if they are old) or pull off if you can help it.
Look at the carb tops and identify the easiest one to remove (I find the second from left is the best to do). (When I say Left I mean its on the left if your sat on the bike).
Remove the 2 screws holding the top on. Be careful when doing this as you want to avoid them falling onto the engine and you having to poke them out.
With the top off you can see a rubber vacuum diaphragm and in the middle of that is the top of the slider. You need to pull all that out so CAREFULLY ease that off the carb - if it tears you will need to replace it they are only thin. These can get stuck to the carb body so nice and easy just roll it off with your fingertip, go all the way around then pull it up slowly. You are removing about 3 inches of slider from the carb.
Once this is out you will see that at the top is the needle retaining plug. Under this is a small light spring so when you pull the plug off be careful not to let this fly off. The plugs can come off with a bit of an unexpected release.
There will be tiny washers on the under and above the E clip so either don't let them fall off or make note of the order.
With this off you can remove or poke the needle up and out enough to read markings around the E clip area. Standard ones have 5D130 or 5D129 stamped on them.
Ivan's kit replaces all 4 needles hence you only need to check one.
Either smile at this point (no markings) or slump your shoulders (markings) and refit everything back.
