KZ650 with Asthma

If not already done, should be using clear plastic tube test to assure correct fuel level in float bowls.

Good Luck!

Patton wrote:

If not already done, should be using clear plastic tube test to assure correct fuel level in float bowls.

Good Luck!

For right now I am using a ruler and setting the float levels based on trials with a spare float and carb body in a clear plastic container of water. I am going to do this on a bench when I get them off the bike. I just wanted to see how much effect I could have by adjusting them a little. So far it has helped, but I do need to do it right when I get a chance. Is there anywhere that sells the little tool for the tubing? My book shows a plug with a valve and nipple for the bowl drain. Unfortunately I don't have a drain that has a nipple on it. That would make it too easy.

Get a piece of clear tubing that is about the same diameter as the drain screw on the bottom/side of the float bowl. Jam/thread the tubing into the drain hole and gently bend the tubing up so that it doesn't kink and lays next to the side of the float bowl. Make sure there are no kinks! Now turn on the gas and watch where the gas stops inside the tubing, it will rise to the same level as what is inside the float bowl. Float heights should be 2-3 mm below the top edge of the float bowl if I remember correctly. If not, someone please feel free to correct me.

anarki650 wrote:

Get a piece of clear tubing that is about the same diameter as the drain screw on the bottom/side of the float bowl. Jam/thread the tubing into the drain hole and gently bend the tubing up so that it doesn't kink and lays next to the side of the float bowl. Make sure there are no kinks! Now turn on the gas and watch where the gas stops inside the tubing, it will rise to the same level as what is inside the float bowl. Float heights should be 2-3 mm below the top edge of the float bowl if I remember correctly. If not, someone please feel free to correct me.

Great, now I gotta go back and do them all over again . Thanks for the help, I hadn't thought of doing that. I'll give it a go once they are on the bike after they are painted. For right now I have adjusted them and found that I have decent throttle response, I still need the choke to start it, but it seems to be going well. Also, I put the air screws at 1.25 turns out and that seems to be doing well. I think I will raise the needle when I get into the carbs and see how it handles if I will need a larger main. Thanks again for the tubing idea for the floats.

Ok, with the floats adjusted and air screws 1.25 turns out it behaved in the following manner.

In neutral, it revs great.

From stop it wants to bog out and die, if I pull the choke up part ways it comes alive again.

Cruising it has issues with the low end power.

At speed it does pretty good if I keep it in the upper 1/2 of the RPM's. Kinda like riding a 2-stroke MX bike.

I think raising the clip will get some of my from stop and lowend woes, however, would it be worth it to up the pilot/needle jet a size? I had expected the mains to be too small so this kind of surprised me.

Also, staying reved went away when I attached the return cable. Seems the slides would stay open a little. Also, no popping or sputtering out the carb. Just hard to take off from a stop without having to slip the clutch or using the choke. Overall this ride was about a 500% improvement on the last one. I actually came back with a smile (frozen) on my face.

If pulling the choke, when at a stop, makes it run better, then you are running lean in that situation. Wondering if you have some blockage in the pilot circuit or your pilot jets are too small. From my understanding, raising the clip will buy you nothing in this situation, as that is only for the main jet use.

Pilot jets regulate from idle and not much past that. Needles primarily effect the mid range and the mains primarily regulate the upper RPM band. There's some overlapping throughout all the circuits, but that's basically how it works. So, if you're needing choke off idle your pilot jets are either dirty/partially blocked or too small.

Thats what I was wondering. The bike idles and revs fine, but under load while starting, even revving the engine a little doesn't really help. Also, the lower midrange is pretty flat. I guess it is time for some larger jets then. Does Z1 still carry them? I only found the main jets last time I looked.

Thanks again for the help,
KC

www.z1enterprises.com/detail.aspx?ID=83

You shouldn't need anything bigger than a 17.5. If you're already running 17.5 pilots I'd suspect a dirty passage or clogged jet somewhere causing your issues.

From what you're describing the 17.5 pilots and moving your needle to the #4 (second from bottom) clip should cure your woes.

anarki650 wrote:

www.z1enterprises.com/detail.aspx?ID=83

You shouldn't need anything bigger than a 17.5. If you're already running 17.5 pilots I'd suspect a dirty passage or clogged jet somewhere causing your issues.

From what you're describing the 17.5 pilots and moving your needle to the #4 (second from bottom) clip should cure your woes.

I'll check them again, but these carbs were tore down, striped, cleaned, blown out with air, and rebuilt using new jets, o-rings, gaskets, etc. I would be surprised if there is a blockage in any of them, but I'll check them again. I put the 20 pilots on order, figure I down to turn on the air jet so it could use a larger jet as it is. Worst case I have a set of larger jets in case I get a chance to swap the pipes. Not sure if I would need them for the B model 4-2 stock pipes, but thats my goal.

I'll try the needles tonight, take it out for another test ride, freeze, and see what happens. Worst case I keep it on top and see what she'll do in a straight line.

Ok, moved the needles up, check the vents, and air screws at 1 turn out. Idle while cold is still a little rough, and I found one carb float is too high, tonight it started leaking out the overflow tube a little, which led to me being the luckiest SOB tonight.

Because gas was leaking a little, I turned off the fuel while doing wheel circumferance calcs for the speedo (I was off as it turns out, guess I should read the directions). Then, having set the speedo I started up and took off. First stop and go appeared to be fine. Bike did pretty well, though it still seemed to be missing something. At 1/2 mile, stopped and was having some issues. When I turned one of the local police was in the lane behind me and followed me. At this point my bike won't get over 15mph, throttle is doing nothing, I figured I had flooded it or done something horribly wrong. I then tried to wave the cop around as my bike was struggling to survive. Instead he pulled me over. It seems he couldn't see my license plate. After explaining what I was doing and why I was out freezing and only going 10 mph in a 45 he wished me luck and sent me on my way. I made it another 300ft before my bike quit, by then he had turned around and headed off the other way.

So, pushing my bike back home I remembered that I should turn off the gas to prevent it from leaking, as you can guess, I found that it was off, a light went off in my head. Turned on the gas, fired up the bike and found that it handles much better now. Most of the power issues are gone, it pulled strong from start to finish. I need to reset my floats again, but it looks like I may have it fixed for the most part.

As to why I am a lucky SOB, according to the state of California my bike is not registered (despite the fact that it is) and it is not insured (despite the fact that it is). I got an involuntary non-operation because I was not in the system as having insurance. I did have insurance, but since my bike was in pieces at the time I figured I would worry about it later. Well, now I am worrying about it a little more .

Only remaining question, is it okay to run the bike with the air screw only out a full turn? I have heard that 1.5 is the norm and anything much out of this range means the carbs are too lean or rich. It seemed to do well, but I wanted to make sure.

Thanks,
KC

Thats great to hear KC. Is the flat spot gone as well now?

Where do you have the needle clipped now?