wont run witout chock on

Purchased a nice 1978 kz650sr not running. Removed carbs and opened them up. They were pretty clean inside so i removed jetts, floats ect and sprayed carb cleaner through every orvice i could find and blowed air through them, put them back on and they wont run witout the choke on.I have taken. the carbs off 3 times and cleaned them by this method and still have the same problem.Is there some other problem or am i going to have to soak them? I need some advice . by the way it has vance and hines exshust with stock filter. THANKS Tim

Does it need the choke for ALL rpm's?
Idle, mid, high....
Also please put the bike and your location in your signature.

Another thing, other than cleaning the carbs, what else did you do to get this non running bike to run?

Post edited by: OKC_Kent, at: 2006/02/19 12:32

Sounds like your bike is running to lean.

By using the choke while running, you're limiting the amount of air intake into the carbs, therefore balancing out the air/fuel mixture.
If the carbs weren't re-jetted to match the increased exhaust flow of the V & H sytem, that's more than likely were your problem is.

You should also check to make sure that the carb manifolds and boots are mounted fully, and that none of them have any cracks or holes, which would also cause a lean condition by allowing excessive air to enter.
Try running the bike at idle and spraying carb cleaner at each individual boot and manifold - if the idle changes (usually by increasing), then you have a leak there.
All it takes is a hairline crack in a boot/manifold to create an intake leak. And sometimes they are very hard to see to the naked eye.

Good luck.

All i did to get running was to clean carbs and install new batt.Most of the time it dies no matter what rpm but sometimes it tries to run at higher rpm but sounds like its starving for fuel. When i first got it running it ran real good with the choke on[idled reved up]but now it doesnt run very good and pops back through carbs

If cleaning carbs is all you did, then I would start by giving the bike a tune-up. Do you have a shop manual yet? Clymers is good, supplement that with a factory manual. Even an owners manual on the bike, if you have it, will give you tuneup specs and steps to get you going.

I think this bike came from factory with vance and hines. Any of you carb guy got an opinion? thanks Tim

it may have come from the dealer v&h but i seriously doubt that kz had a deal with v&h being that vance has only been around for 10- 15 years.

a few dealers would slap new paint and a few extra performance parts to sell a specific model if quota was low.

hello carol shelby.