I am having (what I think to be) some kind of electrical/battery issue. I first noticed my bike (04 cbr600rr) was taking a bit longer than usual to fire, a day later it sounded really weak then the click click click. OK no problem I thought, my battery is five years old. Replaced battery, worked ok for about the first 3 startups then back to weak starts. seems to startup fine when the engine is cold, but its sort of a crapshoot when its hot, it might start it might be weak etc.

battery voltages are as follows:

12.6 just sitting there
13.3-5 reving to about 5/6k rpm with high beams on

edit: also forgot to mention a couple times it died when throttling up to about 4k rpm in neutral
when hot trying to turn the motor over voltage drops to about 10 or 11

anyone have a similar issue?

 

Might have said valve clearances, but as you have just done them, check out your R/R ,coils and spark plugs, once the bike is hot take off a spark lead and put another plug in the lead , hold it against the engine (by the insulated rubber) to test for a good spark, also check for good connections at the battery

 

will try that thank you. interesting though that you mention clearance since I just shimmed my exhaust, is such a problem typical of valves being too tight? perhaps now that I have run the bike a bit I should take another measurement.

 

Still think its electrical

 

probably, this problem was starting to manifest itself before I even cracked open the valve cover, (though all but 1 of my exhaust valves were .04mm+ out of spec (.28mm ideal, measured some at under .24). The only thing that worries worries me a bit is that using the formula: new shim = (clearance - spec) + old shim I would get a weird *** value and have to use the next closest shim I had on hand, The final clearances were a bit on the tighter end of the acceptable value, and Im feeling like I should have used the the shim that would put me on the LOOSER end of the acceptable value. In other words: if my target was .28+- .3, most of the shims I had put me around .25 final clearance where as the .30/.31mm would have made me a little more comfortable.