Broken Mixture Screw

Restoring a 77 KZ1000 and overhauling the carbs found the tip of a mixture screw stuck in the hole. Whats the best way to get it out?

G, Been there, fought that. Try these, 1st, dis-assemble & immerse body in ultra-sonic cleaner. give that a while..Then, with a fairly large dia. (say 1/2-3/4" round (prefeably aluminum) piece of stock, roll over exposed tip of fuel screw.) This will at least flatten exposed tip. Then with a right angle scribe, gently attempt to push offending bit back down thru body. Bear in mind, the passage you're playing with is in fact a jet passage, which has already been enlarged. If you do manage to get broken tip out, without TOO much trauma to body, you'll still have a metering passage, abett probly larger than the rest. by re-installing new mix. screw and comparing flow of other carbs by spraying arisol carb clean thru pilot jet passage, you should get a fair idea of flow rates. procedure is iffy, and time consuming. If anyone has a better attack,I'd like to hear it. luck G

I'be got the broken tip to move up/down but just can't get it to push all the way out. I'm using a bent fish hook to push it back down. I'll keep poking at it.

I've also been there, done that. I had just bought my 77 KZ1000 a couple of years ago and it wasn't running right. When I went to rebuild the carbs I found 3 of the 4 mixture screws were broken off, just like yours. I have a pair of snap ring pliers that came with different tips. One set is a 90 degree tip. I used that to push the broken part out.

Now for the bad news. I have never been able to get these carbs adjusted correctly. No matter what I do, I get a slight hesitation off idle. I've cleaned, changed jets, adjusted float height, and played with the mixture screws. I think the orifices were enlarged by either the broken mixture screw, or the tip I used to push them out with. I hope you have better luck.

I got it out. Went to the local hobby store and bought a set of mini drill bits. Using a dremel tool with a #60 drill bit the broken piece came out. I don't think I enlarged the hole but I'll find out today when I start it up.

Got it running, idles nicely but a slight bog when given a quick blip of the throttle. If I go slowing from idle to full throttle it runs nice, no bogging, but if I go quickly she'll bog and stall. It has pod filters (came on the bike) and stock jets. Thinking of going up one size on the mains. Mixture screws set a 1 1/4 turns out.

Hey gaillarry, while idling, turn all of the mixture screws out a 1/2 turn at a time, until you have found the highest idle rpm. Then turn each one in and out 1/8th turn, hunting for highest idle. If you go more than 3 turns out or idle just keeps rising, you need the next larger pilot jet.

Pull the carb needles, and put the clip in the 4th slot (raising needle) from the top (richer), for now. You can tune this later by moving the clips up to feel for best throttle response and power delivery at/and around half throttle.

Start with the mains...

Mains can be very difficult to tune with pod filters. I would suggest a set of 137.5, 140,and 142.5 jets.
Start with the 142.5s and go riding. Get up to 4th/5th gear, and use full throttle. You don't have to hold it there forever. Do it a few times, and see how the bike feels above half max rpm's.
Then stop, and put in the 140s. Repeat ride, and if you feel more power... stop, put in the 137.5s.
Repeat ride.
Continue this process until you feel either no change in power delivery, or a loss. At that point, go back to the slightly richer previous jet, and your done!



Hope this helps! Don't be afraid to ask anything!

Cheers.

Thanks for the tuning info, I'll different mixture adjustments and maybe adjust the needle.

Just some info...

If you know the bike has stock jets, running with pods means the bike is extremely (DANGEROUS) lean above half throttle.

If you don't change the mains, you could potentially destroy the engine if using more than half throttle.

:blink:

I do plan to put in bigger mains. Question about the mixture screws - which way to richen - which way to lean?

In is lean. As mentioned, listen for pick-up of rpm at idle for each carb. Base settings for mix screws are just that.. Even when new, screw positions varied as much as a turn between carbs. Glad you got lucky..G