Throttle Body Sync Question Using Carbtune Pro

[Steve Kolenda]

I have just done my first throttle body sync on my 2000 R1100RT and have a couple of questions. I am using a Carbtune Pro unit. As found,brass screws 2 turns out on left and right. To get a balance at idle I turned the right one in 1/2 turn. After going through the different RPMs and making my adjustment to the right carb I decided to switch the Carbtune hoses to see if I got the same reading and to my surprise there was a 2 cm Hg difference so I decided to try the other two positions on the Carbtune and only saw a 1 cm Hg difference. Am I expecting too much to think they would read closer to the same when switched? Any comments on the right brass screw at 1 1/2 turns and the left one at 2? Or any other comments.

[tomk99r11]

IMO, that is probably close enough, as much as I hate to say "close enough".

[T__]

I have just done my first throttle body sync on my 2000 R1100RT and have a couple of questions. I am using a Carbtune Pro unit. As found,brass screws 2 turns out on left and right. To get a balance at idle I turned the right one in 1/2 turn. After going through the different RPMs and making my adjustment to the right carb I decided to switch the Carbtune hoses to see if I got the same reading and to my surprise there was a 2 cm Hg difference so I decided to try the other two positions on the Carbtune and only saw a 1 cm Hg difference. Am I expecting too much to think they would read closer to the same when switched? Any comments on the right brass screw at 1 1/2 turns and the left one at 2? Or any other comments.

 

 

Steve, on any of the gauge,, or rod,, or electronic TBI balance gauges you should ALWAYS first use a vacuum tee & hook both gauge hoses to one side TBI.. They better BOTH read the exact same or you have issues with your balance tool calibration..

 

Personally I like to use a simple home made water U-tube manometer as those things are super accurate & read in inches of water..

 

I usually adjust to under 1” of water.. Your 2cm of Hg is over 27 cm of water..

 

Twisty

 

 

[tallman]

Does the Carbtune still require the "reduction" by cutting and inserting a smaller diameter piece pf plastic in the hos?

Mine did, earlier one didn't and when I've compared them, the ones w/the reduction was much better.

[Steve Kolenda]

Yes I have the restrictors in place.

[Ken H.]

The brass screws within 1/2 turn of each other, while not the best ever, is close enough. It's the results that count, not the postion of the screws.

[Steve Kolenda]

Ken,

 

Thanks for taking the time to reply.

[KevinH]

One or more of the slides on your Cartune may need cleaned. I used Alcohol and both my 1 & 2 read the same after cleaning on one throttle side. Good to go after that. I think they get a little crappy laying on their sides in the tool box when stored for long periods of time? Kinda a dead spot – if ya know what I mean.

[Steve Kolenda]

Got a tee and did a comparison of the number one position on the Carbtune to the other three positions and found all to be within +- one minor division of the number one position. So it looks like the worst case would be a difference of 1 cm Hg. Hooked it back up and saw better results than originally. Maybe the shafts needed to be exercised some. I'm going to call it good, put the bike back together and ride.