Mikuni BS34 info

I think i remember the manual sais the idle on a warm KZ1000 engine should be between 950 RPM and 1050 RPM...warm your motor and dial that screw til the tach reads 1000 and you will be close. I have noticed that the ambient tempurature affects the engine performance. I have riden on hot days that aproach 100 degrees and on very cool evenings of about 40 degrees....the motorcycle ran differently from one condition to the other...it runs better when hotter i have found.

As far as the number of turns to screw that idle adjuster...i dont know. I think you have to get the bike to fire up then adjust as necessary.

Those diaphragms at the top of the carbs have a rubber seal that is the diaphragm...if that seal is not seated correctly or has a hole or tear, it will cause an internal vacuum leak...if you took those apart then you might consider taking another look at them. On my rebuild project i found that i had gotten one of those installed crooked and had to fix it. They are a bit challenging to get in there just right.

If you have no manual, i am sure that someone on here knows where one is at online...the manual is your bible. For me, the manual helped me find all kinds of things to adjust and check, get readings on, torque requirements and the list goes on. It would appear that you need two manuals...one for your chassis and another for your motor.

you said that the revving idle problem happened after you touch the throttle...try taking off the cable at the carbs and moving that throttle linkage on the carbs through it's range of motion...see what happens when you let it return home from the spring tension...then apply a bit of pressure to try to get it to close even more...you should not be able to close the throttle linkage any further than it would go on it's own...if it moves beyond the spring load then something is getting hung up on something else. Then make sure that the cable moves freely within the conduit...a frayed cable will get hung up on the inside of the cable conduit and can cause idle problems or even make a dangerous condition to ride with.

peace and good luck.

I have a new cable and it is operating correctly just a bit of slack in it as I have read some where before.The thing that's the pain in the ass is the PO removed the tach so I'm playing RPM setting by ear game.I'm going to check the diaphragm's again today just to make sure.

Dude...there may be an easy way to check for vaccum leaks without taking the carbs off. Try removing the vacuum lines and plugging them with a golf tee...golf tees are cool for pluuging vacuum lines...then set the pet cock to "PRI", the prime setting. If your motor works better with the lines plugged and on prime then you have a leak.

Diaphragms are good have newish carb boots all I need now is for the crank position sensor for my DynaS to show up.I came to the conclusion that the points were shot and that was part of the problem and there is no reason to keep chasing problems till I get the ignition sorted out.

i hope all goes well with your project. I am still working out the bugs on mine...if i keep at it and remember to make it fun I will get it right and so will you. If you happen to find out what might cause my idle to rev so with choke on please let me know. It gets to 4200 rpm if i let it....seems too fast for a cold motor to me.


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take care, good luck and peace

Well.....I stumped again I have the ignition all sorted out enough spark to fry a small child carbs are spotless.I have pulled them apart three times now in the past week to triple check everything.I can start the bike up with the choke all the way out as soon as I push it in it dies.I have no throttle at 2/4,3/4 or 4/4 I can roll into the throttle and as soon as I get to 2/3rds throttle it just falls flat on it's face.I'm to the point now I just want to kick the stupid bike over beat it with a thirty pound sledge.If I can't get this sorted out I'm just going to buy a set of carbs from WG and be done with it.

First of all, step back and take a deep breath. Other people have figured this out, you can too.

I have the same engine & carbs and have had great luck with my BS34s. The only real difference is the ignition system, and I'm not familiar with with Dyna systems.

Make sure you have no air leaks or blockages, and maybe look at your advance mechanism, however that works on a Dyna.

Well got a set of BS34's from WG took a while but these things are beautiful!!! They probably look better than when they came from Mikuni.Any way I'm still having the problem of it not running without full choke.I'm sure it's something stupid I'm overlooking but I'm stumped again.

check your fuel flow out of the petcock there is a filter in the tank and sometimes those will plug or even collapse.

fuel flow is good i've got clear hose on there when it was priming it was pouring at a very constant rate.

messed with it a little more yesterday.I have good spark,fuel and compression.I had a friend help me set the carbs in to the holders better and that helped a little.But it will still only run with the choke all the way out as soon as I press it in it dies.I'm starting to think I have a crack in one of the boots but visually they all look good.Any body have anything else to try?

Try spraying some WD-40 all over the intake boots. If there's a crack, your rpms will rise when the WD-40 fills the crack.
Also, you can let the pipes cool, then fire it up and see if any of the pipes don't warm up as fast as the others.
I don't know anything about BS34's but I do know they have vacuum diaphrams in the tops. Any way you could've missed a vacuum line somewhere?