05 cbr 600rr, when bike temps reach 205 or so, bike will crank so slow it wont start. . Once the bike cools, it cranks strong and fires right up. Any suggestions or starting points, we're a bit stumped on where to begin? Thanks alot.

 

How many miles are on the bike?

generally in this situation, it could mean either your timing is too far advanced, or your starter is worn out and the heat from the engine is making it fail.

Its also possible the battery is just bad. Next time you get it up to temperature, feel the battery and see if its hot. Also, take a volt meter and measure the output of the battery when its cold, and then again when the bike is hot, both with no load and with a load.

If it turns out your battery is bad, now would be a good time to make sure your charging system is working properly. A possible cause of a bad battery is a bad rectifier. or, it could just be old and need to be replaced.

 

4000 miles on the bike. Thanks much, we'll change the battery and check the charging sysyem. Upon reading other treads, it seems this isn't uncommon, just haven't run across a battery causing this oddity. Thanks again!

 

Check the connection on your negative cable. Both ends of it.... I've seen this exact problem before, twice as a matter fact. Clean it and put a tiny bit of white lithium grease back on it before you put it back on. I hope that helps you out.