I will give that’s shot.Hi and welcome!
Usually electronics are what craps out when things heat up. As test, when cold starting, hit various electronic components with hair-dryer and see what causes idle to get rough. Could be ignition-coils, ECU, harness at various spots, relays, diodes, etc. One of these components is acting up when it gets hot.
left the cap open. Helped slightly but still ended up stalling. Also ran it with cap closed and then opened the cap to see if the was back pressure but there wasn’t. Smelled the exhaust and it’s smells rather rich wondering maybe a MAP sensor is bad or possibly bad injector.Maybe... test by leaving gas-cap open.
With modern EFI and high-pressure pump, clogged breather will actually cause fuel-pump to suck tank into smaller crumpled wad.
Wouldn’t they be the same regardless of temp? Not a bike tech so I would know. But warmer air would be thinner I suppose.use vaccum-T and tap into hose going into MAP sensor.
1. measure vacuum with cold engine. Vacuum = ??? MAP-sensor voltage @ ECU connector = ???
2. measure vacuum with hot stumbling engine. Vacuum = ??? MAP-sensor voltage @ ECU connector = ???
MAP sensor hardly ever goes bad. More likely bad leaking hose going to it. Will cause higher-than-actual load signal to ECU. Thus too much petrol.
Also measure IAT & ECT resistance at room-temp and boiling.