Carbtune----LOVE IT!

[Victor Vector]

Just turned over 25K on my 2007 R12R and hadn't had the throttle bodies checked for sync since 10K, though everything sounds/runs great. After much reading on TB sync devices, I settled on a Carbtune Pro 2 pipe model. Checked/adjusted the tappets, air filter, trans and final oil etc, etc. Went for a 20 min ride and then hooked up the Carbtune (hung it from the top of the windshield with a small plastic clamp) and found both TBs to be in perfect sync! Ran it from idle to 4,000 RPMs----identical! That saved me a 180 mi. round trip visit to the dealer and a $50.00 bill. This device is super simple to use--no adjusting or batteries. The instructions say to hang it upside down for R series BMWs because they don't pull much vacuum, but I found it to work perfectly in the normal up position, it pulled the bars 2/3 up the scale at 4K and 1/4 at idle. Best $85.00 I've ever spent.

[roger l]

I have a Carbtune as well and find it is very easy to use. I just did my 12K service and when I checked the sync at idle it was off not quite 2 lines, at 2000 rpm the sync was right on. I did not make any adjustments because I thought that if it was correct at the higher RPM's that was OK. Should I go back and make an adjustment so it is correct at idle?

Thanks
Roger L

[Victor Vector]

It's my understanding that the stepper motors handle the idle sync so I wouldn't adjust it if it idles normally. The important thing is that it's sync'd at cruising speeds. See if it's still in sync at 4,000 RPMs.

[deilenberger]

I did a rather extensive DIY on TB sync on the R1200R on the BMW-MOA website.. but here are cliff notes:

1. If your valves are adjusted properly you probably will never need to touch the TB sync.

2. The steppers take care of idle - and they don't necessarily track (meaning balance can be off at idle and can change).. Ignore balance at idle, it means nothing. Before starting the bike, let it go through the complete startup sequence (where the instruments do their dance) - this also lets the steppers re-zero themselves.

3. The off-idle balance adjustment is most sensitive at around 1,800-2,200 RPM. It becomes less sensitive as RPM increases. If you get it perfect at 1,800 RPM, it will likely be perfect at 4,000 RPM also. The other way isn't necessarily true.

4. Re-read #1. BMW really improved the cable setup over the oilhead (and airhead) bikes. Mine has 51,500 miles on it, and I've never had to adjust the throttle-body balance (I did for the DIY, but it ended up right back where I started, which was perfect to begin with.) If your balance is REALLY off - something else is going on, find it and fix it before touching the balance.