throttle body sync

[scubas42]

It all started when I swapped bikes with a buddy on a Sunday ride. I rode his Boxer Cup Replica (very sweet) while he rode my 04 Rockster and he noticed right away that my throttle was not nearly as smooth as it should be. I have had the bike for about 4000 miles and it has been like that all along (now has 11,500K). I ordered a new accelerator cable from Razee in RI and picked it up a week and a half later when it finally arrived. Ripped the bike apart, install new cable in junction box, go to hook up at throttle and realize its a different cable. check this forum and see there is an updated cable that requires an adapter kit at the throttle tube. I wait 3 days for Razee to open (Mem. Day weekend) call to order kit and ask why they didn't tell me about it, and find out its the wrong cable alltogether!!! Blamed it on BMW microfisch, but Gengras in Hartford CT and A&S in CA had no problem. I am pissed. They order the correct cable and say it will be in in 2 days. 4 days later no cable and another parts guy tells me it was a regular order and will be at least 5 more days. They are making no effort at all to make up for giving me the wrong part-I'm more pissed. Gonna be at least 4 weeks to get the correct cable from Razee's as I still have not heard from them!! Thankfully last week I decided they don't give a rat's ass so I put the old cable back in so I can ride. That was my first and last experience with Razee's.
The good news is the throttle is now very smooth-I'm guessing there was just some dirt in the junction box, however I had to remove the left side throttle body and disconnect cable. After hooking everything back up, I cannot seem to synch the throttle bodies. Started with the cables very close to original position but had to adjust slightly. I am using a very accurate digital vacuum gauge borrowed from work and no matter what I do I cannot get them to stay even when I raise rpm's. Looked at a clymer manual and it says 1150 throttle bodies must be synched with a MoDiTec diagnostic tool. Any truth to that? I haven't messed to much with the BBAS as the bike ran perfectly before, and I thought I would be able adjust the cables back where they were. Valves were adjusted less than 500 miles ago so I doubt they are the problem. Sorry for such a long post, but thought I should let everyone know of my Razee's nightmare. Any help would be greatly appreciated.

Steve

[NoRRmad]

Without knowing much about your disassembly procedure, usually in this case, one of the throttle cables is not fully-seated into the adjustable ferule on the throttle body. Often, the end of the cable is hung up on the edge of the ferule instead of resting on the bottom of the fixture. It's easy to miss without a well-lighted work area.

Using a "very accurate" vacuum meter could lead to problems, if you can't lower the sensitivity for the beginning of the sync procedure. Many here have rigged a simple tubing-only water manometer that is quite accurate enough. There's a thread on this if you do a search.

[scubas42]

Thanks for the reply-I double/triple checked the seating of the cables at the throttle bodies. It guess it is possible one isn't seated right in the junction box, but checking that would require pulling off tank, battery tray, and left throttle body again. That was basically the disassembley I did. I may try a less sensitive vacuum gauge, but I have the feeling I'm just missing something obvious. Thanks again

[boxermania]

You probably have a small air leak on the left TB, this is a common ocurrence after removal or with passage of time. The MoDiTec tool is not required for TB sync.

[scubas42]

As usual, Boxermania was right. After using a mirror to see the inboard side of the left throttle body, I could see the o-ring wasn't seated properly. I still cant get the vacuum to be exactly even at certain rpm's, but the bike runs better than ever. I think the gauge I have is just too sensitive. Thanks again to Boxermania and Norrmad for the help.