overdue maintenance today and a tbs question...

[s.ga.rider]

Today at 22k miles i removed the pair system, changed the plugs and balanced the throttle bodies. It was all easier than expected and the whole project was done in about 2.5 hours.

! question on the tbs, 3 and 4 were turned all the way in to meet 1 and 2. Is that a problem with the screws being adjusted all the way in?

 

[Fred W]

No. That is how it is done at the factory on 3rd Gens. They screw them all in fully and then only open the ones that have higher vacuum to match the ones with lower. That is so that the bypass air is as little as possible which gives the ECU morer range of idle speed adjustment

Typically there will be 1 of the 4 that is fully in, and it is marked with a white dot. Yours must have had two that were equal and the lowest.

 

[s.ga.rider]

1 had the white dot so I didnt touch it. I had to adjust the other 3. My idle was horrible but had to wait till my carb tune pro came in to do the service. I had to adjust 2, 3 and 4 with 3 and 4 being turned all the way in. It was surpringly easy after reading how hard it was to turn the screws.

I posted pics of the plugs on the other forum after 22k miles. I got the factory plugs on ebay for $19 btw.

 

[Fred W]

Yeah, I just swapped my plugs out for the first time at >24k miles and they looked awesome. The days of 8k mile plug swaps are OVER.

 

[s.ga.rider]

Mine were out of spec but not by much.

 

[tempest766]

So that means to always use the white dot cylinder as the reference, right? At least on gen3 bikes?

 

[AlleyCat]

So that means to always use the white dot cylinder as the reference, right? At least on gen3 bikes?

That is correct.... and it appears that is usually cylinder #1 that has the white dot for the Gen3.

 

[Fred W]

So that means to always use the white dot cylinder as the reference, right? At least on gen3 bikes?

Well, that is what it says in the manual. And if you can balance them all by just tweaking the other three then that is what you should do.

However, there have been some cases where an owner went to do the sync and found that one of the other 3 cylinders could not be raised to the vacuum level of the white dot cylinder even when its screw was fully closed. In that circumstance you should close all 4 fully and then use the cylinder with the lowest vacuum as the new reference. Leave that one fully closed and open the other three to bring their vacuum down to the new reference. That way you will have the screws open the least amount possible to achieve balance.

 

[s.ga.rider]

Two wheel obsession has a great video on it.