2003 636 Idle Problem

[GIL with 1 L]

Originally Posted by Twite

So, yesterday I swapped engines, leaving all the same sensors, throttle body, ecu and wiring. Different engine ran fine. The problem is the porting and polishing.
I also discovered the nature of the problem is a bit different than it seemed. I realized the idle was set at about 3500 rpm the entire time. When the idle was set at 3500, the engine would idle at 1200, then ramp up to 3500 when I cracked the throttle, then die or fall back to 1200. If the idle was set to anything lower the bike would not run unless the throttle was held open.
Make sense?
ALSO the engine is literally twice as loud as a normal engine.

I'm out of ideas. Going to scrap the head.

Did a performance shop do the head or did someone go nuts with their dremel