air screw adjustment

Ok so im getting close to firing up my kz650 c1 (1977). Now the carbs have been broken down, cleaned and rebuilt. They look nice, i just need to know where to set my air screw. The manual says 1 and 1/8 turn from seated; however that is listed for a different style of carb that apperently has the air screw inside the float bowl. Mine is loacted abouve the float bowl and is easily accessable when the carb is mounted.

So where do i set this bad boy? Im sooo close to making this beast fire (then i just need to deal with the suspension, breaks, and stearing :blink: )

try 1 1/4-1 1/2 should be a good starting point! goodluck,happy wrenching!

From seated (screwed all the way in then backed out that far) or from the first thread?

Thanks for the help.

im espacally worried, because it will be the first time i run this size motor (i have worked on old international tractors before, but they are a bit different) and i wont know if its running just right when i fire it up. I fear i may run it way to lean and cause a motor meltdown....

seatedB)

lightly seated, you don't want to break the tip off

good point,gotta use a little common sense on that one!does it have a spring under it? :whistle:

Once you do get it running, shut the lights off in the garage after a minute or 2. I only noticed in the dim light that I was too lean as #1 pipe was turning red.

Early congrats on getting it running, its a great feeling.

Yeah there must be springs under the adjustment screws, i could feel them bind as i was seating the screws.

Well i still have to chance the oil, plugs, throttle cables, charge the battery, and make up some kind of temp gas tank to feed the girl. Hopefully she will breath some fire and wake up!!

Thanks for the tip with the lights. How hot is to hot? I have a lazer thermometer so it would be easy to check.

Sheeesh I will try to answer before you ask again

Hopefully someone else will know a good operating temp. I just kind of freaked when I saw mine glowing (thought, this is cool looking, but it cant be right), but I dont know what temp they were at.

I don't know either, but can say an infrered thermometer cannot be used on chrome exhausts. If you do, you'll just reflect and measure ambiant air temp.
DanOz7Five0 wrote:

Sheeesh I will try to answer before you ask again

Hopefully someone else will know a good operating temp. I just kind of freaked when I saw mine glowing (thought, this is cool looking, but it cant be right), but I dont know what temp they were at.

but can say an infrered thermometer cannot be used on chrome exhausts. If you do, you'll just reflect and measure ambiant air temp.

Hmm, I'd argue that point, about not being able to use an IFR thermometer. I've tried mine and it seems to work, may not be 'xactly right though . If you're thinking about the red laser dot, that's just to show you where you are looking. the Thermometer is reading the radiated infrared from the pipes.
I have a hard time getting a repeatable reading, but i think thats because of the shape of the pipes and I have to make sure I read at about the same spot on each pipe, the hottest is at the sharp downward bend. I tried the IFR Thermometer just after starting the bike, and letting it warm up, the first time 1,2,&3 were reading around 260-280or so, and 4 was at 180.
after rebuild all are reading about 220 to 240. It seems low, but I was more interested in the difference between the pipes rather than the exat temp.

well i know i dont have any worries about stuff reflecting off my pipes the rust and gunk will make sure of that!

I have never really trusted the temps i got off it; but they always seem to be in the ballpark of what i need.

Well if they glow in the dark i will know there is a serious issue.

Now the manuel says to turn them one full turn in either direction and listen for the motor reving to set the air screws. Will the motor rev high and sound better if it is lean enough to cause issues? Basically im asking if i follow the clymer manuels instructions could i be setting myself up for motor meltdown??

And final question, how sensitive are the choke seals, i have one that looks shot, but im wondering if i can get away with if for the time being, as i would not like to break the carbs down that far.