[Gearbox]

Just did a throttle sync for the first time yesterday using a pair of dial-gauges.

In accordance with the Haynes Manual I have I closed the air-bleed screws and managed to get a good balance setting and steady tick-over at about 1100 rpm.

I will now try to get the correct CO setting using a Gunson Gastester.

As everything is running smoothly do I need to do this ?

If I leave both bleed-screws closed how does this affect the engine ?

 

[tonered]

GB,

I don't have a Gastester, although I would very much like one.

If you have the mid RPM balanced with the rod, and idle balanced to your satisfaction with the screws full in (or not), then you are good to go.

From there, you just need to ride it. If your fuel mileage drops or the throttle response seems soft, then you're rich. If you get popping on overrun or sneeze stalls, then you are a bit lean. Knowing that, you can adjust the trim a bit at a time. Large trim adjustments will require a resync.

My ST feels best just a tad more rich than the sneeze stall region.

Have a good one.

 

[Gearbox]

Thanks for that Tony.

Just had a go and found out that the tester I bought off Ebay is a dud.
Cant adjust dial into the 'Calibrate' zone in accordance with the instructions , bl**dy annoying.....................

Suitably re-assured I will run it 'as is' and see how I get on.

 

[tonered]

That sucks. I do peek every once in a while on eBay for the Gunson. For the amount of use it would have, I'd prefer to go in with at least another person.

Let us know how it goes.

Have a good one.

 

[kismetcapitan]

out of curiosity, what are symptoms of poorly synchronized throttle bodies?

 

[tonered]

Hard starting, rough running at idle or highway speeds (shaky mirrors), and stalling. A feeling that the motor is out of balance, much the same as out of balance tires.

Have a good one.

 

[Thirdway]

Mine stalls from time to time on a closed throttle and clutch pulled in. I wondered if it was throttle balance or maybe just need the tick over tweaking ?
It's not very often, but it's annoying.

 

[tonered]

Yes, it could be the balance, most likely idle screws or trim. It isn't too difficult to baseline the EFI and sync the TBs.

Have a good one.

 

[kismetcapitan]

I'm rather surprised at how well my bike starts and idles - I never need to use the idle adjuster.

But my mirrors shake at highway cruise (5th or 6th, 60-80mph)