hesitation off idle

When I sit at a light, it idles just fine. When I get ready to go from the light, if I just go straight to throttle, it will die. If I tap the throttle first, then takeoff there is no problem. It is apparently a weak point, but I do not know if it is a needle position or a pilot jet problem. Has anyone dealt with this hesitation off idle? How did you fix it?

Whatcha riding?

If this has just started happening, it sounds like a fuel limiting 'clog' in one of the jets. This might be a good test for some good carb or FI cleaner.

carb sync?

pilot screw adjustments?

Good Fortune!

It's a '79 KZ1000 ST. I just bought it a couple months ago, and it has always done the hesitation. The funny part is that I bought it from a dealer, and they had done a bunch of work to it, already. Clean carbs, new plugs, new wires, new stator, etc. But, I can tell from riding it for awhile, it needs some more work.

It idles very nicely, so I am guessing the pilot screw is pretty good. Maybe, I will need to invest in a carb syncer to see if they are off a little.

Not sure what folk on this forum use, but on another forum the Morgan Carbtune is considered the gold standard. It's a one-time investment, and well worth it iMHO.

megadub72 wrote: ... It idles very nicely, so I am guessing the pilot screw is pretty good....

More than just idle quality, the pilot screw regulates carb performance throughout the pilot circuit, including tuning for a strong smooth pull-away from idle.

Same for sync.

Would suspect that pilot circuit is either too rich or too lean, either of which could contribute to poor performance at pull-away from idle.

Of course, there are many possible conditions that might result in the reported issue, such as noted in the FSM:




Good Fortune!

I had this problem when I had pods. When I re-installed the airbox, the problem improved quite a bit. I tweaked the air screws and was able to get the hesitation completely eliminated.

Pods can be difficult to tune, to be sure. I used a wideband, so it made it much easier. Not everyone has access to one, unfortunately, and is forced to use the plug chop method.

It has the standard airbox, but it does have an aftermarket header. I will adjust the pilot screws to be sure they are set correctly. We will go from there.

With a header all you should need to do is increase the size of the main jets.

Any popping from the exhaust on deceleration?
If so, any such popping may indicate a too lean pilot circuit.

Good Fortune!