Losses some power when hot, possible leak?

[Wheelman-111]

Greetings:

OK, so maybe we should define terms. I assume it's running Badly. Lean and Rich both feel ... Bad. The distinction in "Bad" is found in Operating Temperature (Rich = cooler, Lean = warmer), carbon deposits when rich (on the plug but also anywhere else in contact with spent fuel...), or dry, pale scorched surfaces, Rich = runs better with engine cold (and cooler ambient temps, lower humidity, etc) If you had a stock bystarter, I could see your engine is too lean but runs right as long as the bystarter is adding mixture. But since you have a manual enrichener, and just about every symptom points to rich, it's not clear why you insist it must be lean. A functional temperature gauge would help further diagnose this mystery.

[Cmoped9]

It's running hot it sure seems like, it may have carbon deposit on the plug, but I'm certain it's the new oil. With the yamalube it ran the same way but plug was almost white, not the brown you'd like to see. I've jetted plenty of things before, and it's just odd. It seems like a weird leak making it lean. I'm stumped. I know it's showing symptoms of being rich, but I certainly know it isn't rich. Thanks for the suggestions, I'm gonna fiddle with the jetting, richer and leaner. I'll try and order a new sensor for my temp gauge.