Dirt_Dad said:
I was looking through the service manual and it appears the TBS adjustment is a little more involved than what is required on the Strom.
Looks about the same to me. Don't be flummoxed by all the "disconnect (1), fit special parts (2), (3), and (4)" BS. All they're doing is setting up a "T" connection to tap into an existing hose that has intake vacuum for one cylinder (they must use this vacuum for something else); the other you just remove a cap and put the hose on. It sounds like one bypass screw is painted at the factory to be the "standard" - you leave it along and adjust the other side. I have no idea how hard it is to get to these taps or the bypass screws. On the V-twin Strom it was a bit of a PITA as they were buried in the V of the motor and a lot of guys would install extension hoses to facilitate access. I bet access is easier on the parallel twin.
Also note that you're just adjusting idle balance with the bypass screws. As you run at more and more throttle opening, the effect of the bypass screws on sync diminishes and the sync of the TB linkage dominates. There is probably an undocumented process to adjust this linkage for sync off-idle, but unless you disassemble the TBs, probably no reason to ever do it as this stays in adjustment very, very well. The FJR is similar and I've never felt any need to do any adjustment beyond a slight tweak of the bypass screws to smooth the idle a bit, and even that I've neglected as the idle of the bike has been smooth now for the last 25K or so.
Yamaha's recommendation to do this sync every 6K strikes me as ultra-conservative and since there is no durability aspect if the TB's get slightly out of sync (the bike just doesn't idle quite as smoothly), you really can do this more when the bike "feels" like it needs it rather than religiously. I'm a believer that the biggest danger to carb and FI system reliability is typically the owner screwing around in areas they don't need to.
- Mark
