K7GLE
New member
2000 r1100rt. About 50 miles ago I installed a new O2 sensor and an AF-xied, set at 7. (Also replaced FIs with 4-nozzle R12XX style and had the HES wires refurbished about 100 miles ago but I think those are red herrings.) Pulled & replaced fuse 5 & did the throttle open/shut exercise a couple of times. Valves are slightly slack-fit but uniform. Synched the TBs and rode for a while. Idle was high - nearly 1500 RPM when hot. Screwing both BBS's to lightly snug dropped it to 1200 RPM or so.
Removed the TPS and thoroughly cleaned the TBs off the bike (throttle body cleaner, then scrubbed bodies and all orifices with 3:1 water & Dawn soap, blew dry). Butterfly valves have no perceivable rattle/play/looseness, but do not close completely fluid/air-tight...are they supposed to?
Reinstalled the TBs. Reinstalled the TPS unit. Original setting on TPS was 340 mV. I re-set it to 375 but idle was still high, so reduced it to 340 again which dropped the idle a little.
Set throttle cables with 1 - 2 mm slack (using "tighten left side until TPS budges, then back off 1 turn" method) and synched TBs. Now idles at 1100 - 1200 RPM with BBSs both lightly snug. Pushing butterflies closed (rather forcefully) at idle drops the idle...I haven't checked the ability to set the BBSs for proper idle with both butterflies pushed closed due to insufficient hands and no assistant.
Maybe BBS O-rings? Can't get the rings w/o ordering new BBS's and local bike shop had only one, so I tried to find replacements at the hardware store - all were too thick in cross-section to fit regularly (but when screwed in once to test did not reduce idle any).
I'm at a bit of a loss, and am tempted to ride it as-is until it gets enough worse to diagnose.
Removed the TPS and thoroughly cleaned the TBs off the bike (throttle body cleaner, then scrubbed bodies and all orifices with 3:1 water & Dawn soap, blew dry). Butterfly valves have no perceivable rattle/play/looseness, but do not close completely fluid/air-tight...are they supposed to?
Reinstalled the TBs. Reinstalled the TPS unit. Original setting on TPS was 340 mV. I re-set it to 375 but idle was still high, so reduced it to 340 again which dropped the idle a little.
Set throttle cables with 1 - 2 mm slack (using "tighten left side until TPS budges, then back off 1 turn" method) and synched TBs. Now idles at 1100 - 1200 RPM with BBSs both lightly snug. Pushing butterflies closed (rather forcefully) at idle drops the idle...I haven't checked the ability to set the BBSs for proper idle with both butterflies pushed closed due to insufficient hands and no assistant.
Maybe BBS O-rings? Can't get the rings w/o ordering new BBS's and local bike shop had only one, so I tried to find replacements at the hardware store - all were too thick in cross-section to fit regularly (but when screwed in once to test did not reduce idle any).
I'm at a bit of a loss, and am tempted to ride it as-is until it gets enough worse to diagnose.
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