TOPIC:

Two topics in one here, first is my big issue.

Looking for a little advice on carb cleaning. During cold start with the choke on it revs to like 8k if I go part choke the idle goes down but I have to keep playing with it as it warms up to keep running. During this time throttle is a mess, it'll die or it'll go up and not come down. Once it's finally warm, it runs fine. Idle is fine, throttle is fine. My thought is that the choke air circuit is working but the fuel circuit is not on some of the carbs, really leaning the shit out of some of them causing out of sync and lean issues.

Now, I've never had to clean or care about this before so I'm really not sure what I should be looking for. I've pulled the plungers, blew on the long copper dip stick to ensure they all blow through, blew out the pathway in the bowl where the dip stick goes into. Is there anything else that could be causing that?

For reference im running stock exhaust and stock airbox with K&N filter, nothing fancy.

For my second question, I have seen different pictures of the shop manual with different stock jetting on the 24S. My manual says 100 main, 16 pilot and another one says 102.5/15. Im currently running the 102.5/15 as im guessing that was a revised version where they made some adjustments? As for float levels, I have seen this a bit of a heated topic on this board, on how to check. As my carbs are apart, im checking float height, and it looks to say it should be 30mm. Ive just never heard that called "Design Fuel Level" so I want to make sure thats correct and not meant to be something else.

Make sure the choke pick up tubes are open, and the passage inside the float bowl too. These passages often block up.

The jetting differences you mention won't matter. Be sure to remove the pilot jets and hold them up to a light to be sure they are open.

Regarding the float height, I don't have the proper manual for your bike but Kawasaki doesn't typically supply that information. They usually specify fuel level though. You would be safe to set the fuel level at 4mm below the carb edge as measured by the "clear tube test". That's a very common level as specified on the VM family of carbs for all different versions.

Good luck

Oh and by the way, if I were you I'd bust down the carbs fully and clean all the parts fully. Then reassemble with new O-rings. Cycleorings.com has a VM kit that should have most of what you need.

Thanks for the info

Nessism wrote: Make sure the choke pick up tubes are open, and the passage inside the float bowl too. These passages often block up.

I believe I did that this time. I blew through the long thin copper tubes (bottom left in my pic) and air went through. And I blew out (with an air compressor) those passages inside the bowl that the tube sits in. That all sound right?

The jetting differences you mention won't matter. Be sure to remove the pilot jets and hold them up to a light to be sure they are open.

Nessism wrote: Regarding the float height, I don't have the proper manual for your bike but Kawasaki doesn't typically supply that information. They usually specify fuel level though. You would be safe to set the fuel level at 4mm below the carb edge as measured by the "clear tube test". That's a very common level as specified on the VM family of carbs for all different versions.

Totally get thats the best way to set them, but its incredibly inefficient to check it, take it apart, bend the tang, put it all together, fill it will fuel, check it again, drain it, take it all back apart again, bend the tang, fill it with fuel, etc..

Here is what my manual says, maybe the 30 means something else,



Here is what the manual says about cleaning the circuit. Seems like what I have done, the issue is that it talks about 'starter pipe bleed holes' and I dont see anything like that unless they are up in the carb body. The carbs in this manual also have the mixture screw under the bottom coming through the float bowl, where mine are actually on the sides (like most carbs are). My bike is a 77, and the manual is for a B1 so im not sure if I have carbs from a later model or what. Im not sure if mine are slightly different then and make the pickup pipe is slightly different. Sorry lots of questions but I feel I understand 90% of whats going on here its jsut im not use to Kawi's and there seem to be some nuances I need to pick up on.

To check the fuel bowls fill them with cleaning solution (fuel, mineral spirits, etc.) and check to see if the small well the starter tube goes into fills up. The little orifice at the bottom clogs really easily especially if the carbs have sat for a while.
I believe the starter pipe bleed holes are close to where the tube meets the body of the carb. They are very small and often overlooked.
Good luck

For what it's worth I was working on a set of VM22S the other day and found that presetting the floats at 24 mm from the surface of the carb body got me right into the ball park for the clear tube method.

You didn't mention the year or model so I don't know if it has points or electronic ignition. What you are describing could also be the ignition timing off. If you still have points I would suggest that you set the timing before making any adjustments to the carbs. Twice this past week I've had bikes, kz650 and CB450, act just as you describe. Full choke very high idle and throttle way too touchy until warm. Both bikes had the points worn and as a result were very late (retarded) timing. Once I set the points at the F1 and F mark the carbs were easy to adjust and sync and the throttle action made more sense.

I believe, but am not positive, that this drawing for 26mm Mikuni carb is applicable to the carbs at hand:




Good Fortune!

jdvorchak wrote: You didn't mention the year or model so I don't know if it has points or electronic ignition. What you are describing could also be the ignition timing off. If you still have points I would suggest that you set the timing before making any adjustments to the carbs. Twice this past week I've had bikes, kz650 and CB450, act just as you describe. Full choke very high idle and throttle way too touchy until warm. Both bikes had the points worn and as a result were very late (retarded) timing. Once I set the points at the F1 and F mark the carbs were easy to adjust and sync and the throttle action made more sense.

I had mentioned it in my second post, but its a 77 and its still running points. I'll check the timing again and hit the points with some fine sandpaper to ensure they are clean. I want to replace with an electronic but there seems to be some varying opinions on here about the direction to go, so I havent made that decision yet.

Since it's running now doubt you need to clean them. Especially with sand paper. That will guarantee and early failure of the points if you sand off the special coating on the mating contacts. Before you drive yourself nuts with the carbs set the timing. If unsure how here is a video of the method I use. The video is for a 2 cylinder Honda but works on any 2 or 4 cylinder bike. Just substitute Left/Right with 1&4 and 2&3. Actually on your Kawi the left point set is 1&4 and the right side points are 2&3.

Tore them all the way apart and didn't notice anything stuck, clogged etc. Still took extra care to make sure all the circuits were as clean as I had tooling to work with. Put them back together and the choke circuit seems to be corrected. Checked timing and it was spot on, so it didn't need touched. Hooked up the sync and moved the slides a smidge but they were very close already. It still doesn't come back down to idle like it should, I sprayed the boots and carbs with carb cleaner to see if I could sense a leak but there was no change so I dont think its a vacuum leak. Havent checked valves yet so that'll be next on my list.

I checked the float heights on two of my carbs with the clear tube method (mine was pretty ghetto, took some overflow line off the carb trimmed it down and pushed it into the drain, then took some clear fuel line and pushed it over top of the drain line. Taped all the other floats up so fuel wouldn't go into those carbs. It dripped fuel but was able to get some good measurements. 3mm from the bottom of the carb body was 25mm float height on both carbs. Hopefully that helps someone in the future get close.