KZ440 Single Carb Conversion

TexasKZ wrote: The carb should never overflow. If it does, then the needle valve is no longer working or is badly mis-adjusted.

If the bike has a vacuum petcock that does not have a vacuum line hooked up to it, then the only way to get fuel from the tank to the carb is to turn the lever to PRI. If there is no vacuum and fuel flows, even a little, when the lever is on RUN or RES, then the petcock likely needs rebuilding.

I was waiting for someone to say it!

Okay, thanks for that. I'm still new to the inner workings of carbs (taught myself by using forums like this!), but the stock carbs used to dump gas out everywhere when I left the prime on. Now I know better

Fuel definitely flows with the prime on and not when it's set to run or reserve. I'm about to go out and check on where that slide is sitting. This might sound dumb, but is there an easier way to check? Maybe by trying to run it without the handgrip attached?

Thanks for all the help everyone! This thing has been sitting in my garage for about three years now while I've slowly collected the money for parts, and it's absolutely killing me that it's just sitting there fully assembled and not being ridden around.

I had very similar problem with my single carb conversion on the 440. I used an after market throttle and cable and could get the bike to start and when it did, it reved to hell. It took awhile to figure out that the after market stuff was keeping the slide half cocked. I ended up switching to the after market cable with the stock throttle body and everything worked.

Okay! So after a night of headaches I discovered I wasn't getting spark for some reason now. I took the coil off and tested it, and everything tested fine. I noticed that the right spark plug end was very loose, pulled back the boot and the end fell off in my hand. Completely melted off of the wire. I wonder how many problems this might have been causing me in the past.

Anyway, I repaired it, made sure the plugs were gapped correctly, have spark, and now the bike turns over. Now it fires, but won't seem to idle. I can see the fuel flowing through the filter, and it "runs" while the starter is turning it over, but doesn't seem to come high enough to actually start. Like I said previously, I'm kind of new to these mikuni carbs, and adjusting the air and idle screws didn't seem to make any difference whatsoever. Do you happen to remember whether yours came out a lot or only a couple turns? Or any other ways to adjust it that I may be forgetting?

Again, extremely grateful for your time guys. KZR has an awesome community.

I'm new to these carbs too. However a good diagnostic tool would be to hit the air filter with some starting fluid and see if it runs better or worse. If it does then its deffinatly a carb adjustment. If not then it may be something else. Just my 2 cents.

Baretto, .do you happen to remember the brand ofk the bar end mirror on your bike, and/or where you got it?

I'm pretty sure they were just standard, cheap bar end mirrors on amazon-

www.amazon.com/Universal-Inceased-Davids...words=bar+end+mirror

No eBay APP ID and/or Cert ID defined in Kunena configurationJust in case anyone ever needs a throttle cable, this one fits the stock throttle grip and the mikuni vm34 carb. It's a bit long but for 9$ including shipping you can't beat it.

just curious, i have done the same conversion, but with a K&N filter and manifold from 11th hour. i have put the exact jets in, as you listed for what worked for you, but it runs extremely rich, so i have went down to as low as a 17.5 pilot and a 140 main, still super rich. now it comes to the float i assume. mikuni said 22mm to 24mm on the tang adjustment. do you recall what yours was set at? my elevation is similar to yours btw. but this thing turns clean plugs to charcoal in a a matter of 5 mins of running, it idles decent, after a few tang adjustments, but when i throttle up, it sounds bad, smells like fuel, and bogs at about 3500 rpm... im losing my mind on this thing! do you recall what your tang is set to on yours? and regardless of what mikuni said, should i continue to add height to the tang to lean it out?? :evil:

I'm going through the same exact scenario. I did find this to be helpful though. www.amckayltd.com/vm34-36.pdf
Hope it helps.
BTW if you figure it out please post your findings.

I will certainly let you know as soon as my finding perhaps change the way this paper weight is running. I know its within the carb, before i changed the exhuast to a low restriction exhuast and a low restriction air filter, with the cv carbs its ran great of course, but either way before i press the start button, when i get off work in 20 hours of course, im going to re assure the specs on the points and do a valve adjustment, i broke the bike down to clean it up about a year ago, and it has been a on going project for about a year now, im ready to ride finally an now this fun. :sick:

For anyone else who looking for info on the vm-34 carb . I live at 5000 ft in a dry climate. I'm running a single vm-34 on my 1980 kz440 Ltd. The following is my setup on the carb. I have a 11th hour industries 2 in 1 manifold. Although the manifold was extreamly lopsided because it is a left side exit (feeding the right cylinder to much gas and the left very little) I was able in install a needle valve on the rich side of the manifold and run it strait to the air filter to overcome that problem.



I'm using a #30 pilot jet, #170 main jet , needle clip at 1st position ( the tip top), air screw 3 turns out and a K&N high flow air filter to top it off (helped a bunch for getting extra air) .