I have a 2003 RC51, that is pretty muchly stock except for a power commander. I bought it wrecked from a insurance auction. It starts fine and runs good but only after a few minutes it gets hot enough where the exhaust pipe comes out of the engine block the pipe glows red. I noticed it the other day when I road a few miles and shut it off the pipe was red from heat. I felt alot of heat on my legs and thought it was just normal heat coming from the pipes. But when I seen the pipe glowing I shut the bike off. Then I could hear antifreeze girgling. The temp light never came on. The antifreeze and oil look fine. It does not have any leaks any where. I did notice the right radiator is slightly bent in. It's not alowing the fan to turn. Any help would be greatly appreciated. Thanks.

 

el. o. el.... I <3 RC's.

First off, make sure the coolant is full and bled - if its got air pockets, it'll cause issues.

Is the temp gauge on the dash working? If not... you got air in the cooling system, lots of it.

The fans HAVE to work on these bikes. If the fan isnt coming on, it'll overheat. Hell, it will overheat with the fans on - these things just run hot, alot. Keep an eye on the temp reading. And it'll leak too, just give it time.

Once thats done, zero the power commander... if the pipe is still glowing red if the coolant system is sorted, its probably dumping too much fuel into that cylinder. Could also be a stuck/leaky injector.

If the bike was crashed hard enough to bend up a radiator then check the forks/swingarm/triples/etc and make sure everything is straight.

 

Like .RJ said:
Check the coolant. Pay attention to the temp guage. Zero the powercommander, or try the dan kyle map from rc51.org. It works very well.
The fan needs to spin. If you can't make it spin, then you need to buy another radiator. There's no way you're riding without a fan. Since it's an sp2 you should have two fans, one for each radiator. So you may be ok for now, but the not working fan is probably just blocking airflow if it's not moving.