Slight hesitation when throttle is first opened

I'm sure many of you saw my saga previously with my bike...ugh.

Anyway, it's running great now, fires up on the first crank (I love that Dyna coil!).

Only problem that I have noticed is that it sputters/hesitates a bit when you first open the throttle and/or have it barely open. It's really not even noticeable in first-third gear, but you definitely notice it in fifth when you're trying to cruise with the throttle barely cracked. There are no problems at any throttle position above that.

What should I be looking for that might be causing this?

Your mixture is getting too lean when you open the throttle. Are you using pods or the original airbox? I had hesitation problems with pods. After re-installing the airbox, I still slight hesitation until I adjusted the air/fuel mixture screws. Screwing them in makes the mixture richer I think. I'd try 1/4 turn at a time.

Nope, I still have the stock airbox. Carbs were just rebuilt.

I have the screws at 1 1/2 turns out, which is what they were before and it ran good like that.

Also I think you turn them out to richen the mixture?

Are you sure your floats are ok? Had exactly the same symptom and found one float full of gas. You can still get those floats at motorcyclecarbs.com for $24.00. I luckily received one free from a member here. This is one awsome site! If you have one plug that's turning black (too rich) that might be it. If both plugs look normal or same disregard my post.

ghunt81 wrote:

Nope, I still have the stock airbox. Carbs were just rebuilt.

I have the screws at 1 1/2 turns out, which is what they were before and it ran good like that.

Also I think you turn them out to richen the mixture?

If your adjustment screws are on the side of the carb they are air adjustment screws,, you turn them in to richen the mixture. If they are underneath in the front they adjust the fuel, you turn them out to richen the mixture.
That off idle stumble is usually the mixture being to rich to begin withand when you open the throttle it leans the mixture suddenly.
Seeing as how they were recently cleaned and rebuilt the passages will be cleaner.
Try leaning the mixture 1/4 of a turn, if performance deteriorates, go the other way.

Contact Wiredgeorge.......he'll square you away.

I forgot to really reply to this (and the weather was crappy so I didn't ride much).

I turned the air screws out 1/4 turn on both sides.

I noticed no noticeable improvement in driveability, but it was popping from the exhaust more at idle. I turned the screws back in to their original position of 1 1/2 turns.

I have not yet tried turning them in another 1/4 turn but I will try that sometime.

The Milkman wrote:

ghunt81 wrote:

Nope, I still have the stock airbox. Carbs were just rebuilt.

I have the screws at 1 1/2 turns out, which is what they were before and it ran good like that.

Also I think you turn them out to richen the mixture?

If your adjustment screws are on the side of the carb they are air adjustment screws,, you turn them in to richen the mixture.

NO, he has a 750 twin like mine. The mikunis have the pilot screws on the sides and you back them out CCW to get richer (more gas).

I also recommend checking float adjustment (gas level) using clear tube method. A stumble when you open th throttle at lower RPM is the classic symptom of too low fuel level in the bowl.

ghunt81 wrote:

I forgot to really reply to this (and the weather was crappy so I didn't ride much).

I turned the air screws out 1/4 turn on both sides.

I noticed no noticeable improvement in driveability, but it was popping from the exhaust more at idle. I turned the screws back in to their original position of 1 1/2 turns.

I have not yet tried turning them in another 1/4 turn but I will try that sometime.

Won't help. Check fuel level and check for air leaks. Check to see if you have 45 pilot jets, because 50's run better (a little richer).


As last resort, you can raise the needles one notch and it will give you better throttle response.

I actually did check the float level a little while back and both were good, and right within spec.

And yeah I do have #45 pilot jets...that's what came in the rebuild kit. Spose I could swap to 50's easily enough.

ghunt81 wrote:

I actually did check the float level a little while back and both were good, and right within spec.

Did you check the fuel level with a clear tube?

yes...