TOPIC:

i just purchased a kz 750 and ive had the bike started and let it run for a awhile but it stalls when i push the choke down i sit just to cold or does it take a long time for it to warm or is it somthing else thanks

How long do you let it stay on choke?
If your tachometer is working what is the RPM?
It could just be cold, or it could be idled too low.
Have you cleaned the sparkplugs?
has the bike had a tuneup? (carbs cleaned, new plugs, plug wires, etc...)

I would think that it is something simple like the idle being too low. But, if you just got it, I would go ahead and check the bike over anyway. A good check and cleaning is a must for a "new" bike, you never know what the last owner did or didn't do

My bike had problems with the sparkplugs and after a good cleaning and idle adjustments she ran great.

Good luck

i got new plugs im not exactly sure on the rpms but think it was around 1000 but not sure and it hasnt had a tune up yet only new correct plugs and it has been in the 20's lately

cold is a factor, but if the RPMs are around 1000 on choke, I would think that you might need to up the idle just a bit.
I don't have any specs on your bike, but 1000 rpm just seems too low on choke.
My 4 cylinder 550 idles at about 1100, and chokes at about 1300-1500 on the tach.

thanks for your help ill play with it today and see exactly where the rpms are at and adjust the idle when i find that thanks again

Please edit your signature in your profile to add your bike year/model and possibly, where you live so responses can be fine tuned a bit. Is the bike a twin or four? Shouldn't have to ask you to provide basic info for answering your question plus there may be someone very near you willing to help solve a problem on-site! wiredgeorge MODERATOR

My KZ650 has to choke for a couple minutes before it will idle by itself. I have my idle set to around 1200-1300rpms.

I get it to choke around 2k rpms though, is that too high? I ask because NOS said he is choking at 1300-1500... If I put the choke all the way on it goes up to 4-5k (which I don't do).

4-5k sounds too fast for me
I don't know the specs on your bike, but I think you may need to look up the proper choke settings.

If my choke setting seems a little low, I live in South Texas, and it hit 87 degrees here today. I have no need to choke much more than 1500.

my factory Idle setting should be around 1100 I think (don't have manual in front of me ATM )
To correctly set idle you should use a tachometer (not the one on your bike. Those are not accurate enough for the correct Idle adjustments.) You can also set it by "ear" ie, lowering the idle and rev slightly and release back to idle quick. If it stalls try speeding up the idle.

It does take a few minutes for them to warm up. I start with full choke, put on helmet and gloves and at about that point turn the choke down to about half. RPM here should be about 1300. Ride it down the end of the street and around the corner and at that point I'm turning the choke right down or off.
If you are just running on the center stand then you should be able to turn the choke fully off after 3 - 4 minutes. If it stalls then you may need to adjust the idle using the large thumb wheel underneath and behind the middle two carbs. Alternatively the carbs may need to be syncronised.
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Woodstock ON Canada
1980 kz750 E1, 4->1, K&N pods

DivideOverflow wrote:

I get it to choke around 2k rpms though, is that too high? I ask because NOS said he is choking at 1300-1500... If I put the choke all the way on it goes up to 4-5k (which I don't do).

This sounds exactly like mine too. If I full choke it, I am up in the 4-5k range too. I usually choke between 1700-2000. It seems to take at least a good five minutes at this rpm for it to be ready (sometimes longer), although I should say it has been hovering around the mid-40's here in Seattle.

Same here, if I pull the choke lever up all the way, it will jump into the 4-5k range as well.

NOS, you mentioned that is too fast... how do you adjust that? (besides not raising the lever all the way)

There is an adjusting screw/bolt with a clamp nut on it on the choke rod.
I don't want anyone to think that what I say is exact. But, I have always followed the "no more than double your idle speed on choke" rule. Once again it depends on where you are in the world, your elevation, humidity, and temp. are all factors that you should consider.

That being said, I say no more than double your idle speed just for precaution. To me, I think that starting a cold engine with cold oil and cranking up the RPMs is just asking for trouble. (Once again, there are factors that can change your personal settings)

Now I only have a KZ550 LTD and a KZ750 Spectre, so on other bikes the idle speed and choke may be different. In that case I recomend having a manual, or finding out your bikes specs on the web.
But, I still believe that not much more than double the idle speed is the safest way to go.


If anyone has any more info, or has another opinion, I welcome it. No one man knows everything (but he can try)