Hesitation on a steady throttle !(help)

[panman40]

Hi all,
Got a Slight problem with the ST13 i just bought<
On a steady /light throttle fairly low rpm's on a flat road sometimes it almost seems as if it's running short on fuel and when you feed in a little more throttle i'ts a bit hesitant to pull ?.However give it some more right hand and no probs then.
I'ts done 6000mls but i have only done 1000 of these, trouble is i cant remember if it was like it before i changed the plugs and had the tank up in the service position!. Also i tried to see how many miles i could do on a tank of fuel, (290mls) before i filled up so not sure if i picked up any dirt from the bottom of tank?
Any help with this would be gratefully received!!, Excellent Site!.
Martin (UK).

[wjbertrand]

Hi all,
Got a Slight problem with the ST13 i just bought<
On a steady /light throttle fairly low rpm's on a flat road sometimes it almost seems as if it's running short on fuel and when you feed in a little more throttle i'ts a bit hesitant to pull ?.However give it some more right hand and no probs then.
I'ts done 6000mls but i have only done 1000 of these, trouble is i cant remember if it was like it before i changed the plugs and had the tank up in the service position!. Also i tried to see how many miles i could do on a tank of fuel, (290mls) before i filled up so not sure if i picked up any dirt from the bottom of tank?
Any help with this would be gratefully received!!, Excellent Site!.
Martin (UK).

The Turbo Tom Fuel Pressure Regulator (FPR) will totally solve this problem.

http://tinyurl.com/nsdu5

[Ken]

Many ST13 owners experience a flat spot in the 3400-3800 RPM range. Is this where you notice the hesitation?

[panman40]

Many ST13 owners experience a flat spot in the 3400-3800 RPM range. Is this where you notice the hesitation?
Ken, the hesitation is at 2-3000rpm ish cruising on a light throttle, no probs further up the revs or larger right handfuls,
I cant help thinking i shouldn't have changed the plugs /lifted the tank or ran low on fuel !, I emailed Turbocity and they said thats how a Standard ST 13 runs, A bit weird for a touring honda!
Cheers.
Martin

[Ken]

Martin - probably a longshot, but is it possible you are upshifting too quickly? In my own case, I get out of 1st pretty quickly but tend to stay in 2nd until I'm in the 3600 range.

[Txrebel]

I too feel the moment of hesitation when easing along at about 2800 then start coming on with the throttle. Kind a feels like a hick up. But this is only present at the 2500-2800 range. I don't think the engine likes being crusied at this low an rpm. By the way I have 22000 on mine now. I just try to remember to get the rpm's above 3k and all is well...

[CCC]

I noticed the same problem when I was up in the Yukon an Alaska last month. I was thinking it was the antiknock system retarding the ignition when I was forced to use regular gas. This is only my own theory though.

[wjbertrand]

Ken, the hesitation is at 2-3000rpm ish cruising on a light throttle, no probs further up the revs or larger right handfuls,
I cant help thinking i shouldn't have changed the plugs /lifted the tank or ran low on fuel !, I emailed Turbocity and they said thats how a Standard ST 13 runs, A bit weird for a touring honda!
Cheers.
Martin

The flat spot is due to Honda leaning out the fuel mapping in order to meet the 2008 emissions requirements they brag about. I suspect that the 1400 - 3500 RPM range is used in the testing procedure. I wish Honda had just built the bikes to meet the current standards instead of future ones if it involves a drivability issue like this.