Power loss and overheating

[jward]

I have a 2006 B&W 150 with 700 original miles. It did sit (inside) in a tropical environment for several years unused. It ran fine for a few months until I left it with no treated fuel for a few months. Once again it did fine after I cleaned the carb and have treated the fuel since.
Recently it runs fine every morning when cold and every time after 10 minutes it suddenly loses power (can’t make it up the hill) and heats up to red line! After I let it cool it’s okay for another 10 minutes.
The cooling system seems fine in that I can feel it hot on both sides of the pump and in the reservoir. I have burped out any air with the reservoir cap off. I have removed the thermostat (which tested okay in hot water). I have not flushed the system as it looks good and the radiator grill is new and clean, fluid and level looks good.
I took the carb to a dealer and had the jets and carb cleaned thoroughly and use fresh gasoline. I did not drain the tank thoroughly. I did check the fuel filter. I don’t see how it could be fuel supply if it runs fine when cool. I’m a bit suspicious of the “auto bystarter” which I believe is some kind of electric choke. Another thought is a bad CDI (capacitive discharge ignition)?
I hope it’s not a warped cylinder or rings or valves from overheating and it seems like that would be constant power problem even when cool. I don’t know which comes first: overheating or power loss as they are simultaneous. Perhaps I should have the valve clearance checked?
It seems like I read a forum with similar (KYMCO) problem and he replace everything without improvement!  I’m at the point of replacing the carb or selling the bike!
I don’t have access to a repair shop here on the island. Any ideas?
Jon

[naughty lee]

If you have checked your oil and coolant levels and they appear to be in order, you could try an additive to your coolant, there's in available here in the uk that makes all bikes run much cooler

[MotoRandy123]

My guess is the carb is still a problem. When cool you are running on the choke and
everything is rosy. After it warms up the choke shuts off and you are way lean so it
overheats. The pilot jet is still clogged so just buy a new one or soak it in something
 like Hoppe's gun cleaning oil. It could also be an air passage that lets the pilot breath...

[MaryK]

I have a hard time understanding your message.  Is it just a power problem when the engine is at operational temperature ?

Or is there a problem with the engine overheating ?

If there is an engine overheating problem, then the thermostat may be faulty.

Scoot safely,