Increased surging?

[JRE]

On my 2014 ES (6k miles), it always had very abrupt 'surging' acceleration in low gears when in sport mode but now it feels like T mode is surging as well - more than it used to. Maybe it's just my poor recollection (haven't ridden much since the winter due to weather/travel/etc) and I did spend some time on my XRL early this season so it could be throwing me off. Just wondering if anyone noticed something similar and would might be the cause. I haven't touched the ECU but have considered it.

 

[WJBertrand]

I've heard syncing the throttle bodies helps with this, I plan to try this soon myself.

 

[Rodge]

On my 2014 ES (6k miles), it always had very abrupt 'surging' acceleration in low gears when in sport mode but now it feels like T mode is surging as well - more than it used to. Maybe it's just my poor recollection (haven't ridden much since the winter due to weather/travel/etc) and I did spend some time on my XRL early this season so it could be throwing me off. Just wondering if anyone noticed something similar and would might be the cause. I haven't touched the ECU but have considered it.

Did you mean a XLR? engine with a CV (constant vacuum) carb?

 

[RhodeTrip]

Balancing throttle bodies did help with the twitchy throttle. You will want to read the procedures by SpeedStar and back out the reference side (white paint) it will make a significant difference. I only went 90 deg out on the reference screw because I am leaving on a trip. My next adjustment I will back it out as described.

Jim

 

[Kevhunts]

A throttle body sync may help smooth things out a little bit and there is a manufacture who sells throttle tubes with different "pull" (for lack of a better word) of the throttle cable but I think you will find a ECU flash will aid in fueling by removing the emission related throttle restrictions and pretty much eliminate most of that snatchy on/off feel.

 

[JRE]

Did you mean a XLR? engine with a CV (constant vacuum) carb?

XR650L

Thanks for the replies guys...I'll look into it

 

[groundhog]

I've heard syncing the throttle bodies helps with this, I plan to try this soon myself.

Throttle body sync got rid of the surging for me. 4500 miles later it's back again, but I was told on here the TBS should be done every 4,000 miles. So mine will be done again on my next service due very soon

 

[WJBertrand]

Throttle body sync got rid of the surging for me. 4500 miles later it's back again, but I was told on here the TBS should be done every 4,000 miles. So mine will be done again on my next service due very soon

Did you modify the fixed setting on the painted screw or just sync the other TB to match it as it was?

 

[JRE]

Balancing throttle bodies did help with the twitchy throttle. You will want to read the procedures by SpeedStar and back out the reference side (white paint) it will make a significant difference. I only went 90 deg out on the reference screw because I am leaving on a trip. My next adjustment I will back it out as described.

Jim

Thanks, I went and read his thread and I believe a TB sync is in order for me because I've noticed a rough idle (seems too low) which apparently is a symptom of this as well. I think I'll bring it in the to dealer to have them adjust it under warranty as some have done under the guise of idle stumble.

 

[Rodge]

Hopefully the TB sync will tame the surging...
However, riding a cable operated CV carburated engine with a 1:1 throttle ratio for a while then coming back to the ST will exacerbate FI woes....
There is a cure for that, FT ECU with a proper map, that means throttle map 1:1 ratio or close to it AND revised timing tables...
You won't believe the difference...
If I did not manage to get it to operate like it had CV carbs I would have sold my ST...
Cheers