Random mid rev bog

I thought I had everything worked out. Bike (09 FE450) was running very well with the new fuel pump. Then 4 hours into my last enduro, with 2 hours to go, the bike starts bogging when rolling the throttle. It was more or less random, lost a few minutes here and there, and got stuck on a simple hill climb when bike stalled.

I thought it might have been bad gas, perhaps water in the gas since the symptoms appeared after the second gas stop. Got the bike home, took the tank out, dumped out all the gas, put fresh stuff in. Bike seemed to run fine. Then after 30 minutes into a trail ride yesterday, the dreaded bog re-appears.

Any ideas? It could be ANOTHER bad fuel pump (this is the third one already). Thought I would ask before I go into diagnostic mode.

I think the fuel pump is OK. I hooked up a pressure guage, and it is reading a constant 55PSI even when the bog/misfire occurs. I am starting to suspect an electrical/spark problem.

This is getting really old. Bike is brilliant when it runs, but can't keep it runnning for more than a few hours without another problem

Symptoms are:

- bike starts and idles fine
- random bog on throttle roll-on
- when the bike is misfiring, it also occurs when running at speed (spits and coughs)
- when it is bogging/misfiring, bike may run smooth but power is down
- right now I would say bike is bogging 70% of the time

Thought it was the spark plug cap. Negatory on that one, problem still exists with new cap.
Next on the list was the crank pulsar sensor.
Bingo! Bike runs perfect after replacing it.