Starter won't crank when hot...

[dolly_parton]

I'm ALMOST there! This bike runs like a champ and looks and rides 20 years newer thanks your help.  

One puzzle piece missing. Bandit starts fine when cold, may have to crank about 5-6 times (yet to clean the carbs), but once it's up, it runs without fault. HOWEVER, if it has been running more than 10 mins, or helling around at 10k rpm for 5 mins -- once shut off, it refuses to start.

The starter will then barely crank twice, if at all, and sounds as if it is pulling life support from a comatose battery (yeah, but it's new. Can't be the battery because it starts fine cold, at least 45 mins later). I can keep mashing the starter button into a pulp but it won't even SUGGEST a start.

I can hear the putt-putt on the first crank so the cyls are firing, yes? The lights will dim excessively, and if I thrash the bike back and forth, the starter may do at most three more successively weaker cranks, for whatever reason. Meanwhile passer-by thinking I'm shagging the bike.

Cooling system is checked. Connections are fine as far as I've checked. Gas fresh, new iridium plugs, new reg/rec from a 2008 suzuki500 something or other.

So NO start when hot.

p.s....About once every ten rides, the bike will have trouble starting and keeping idle, and will 'growl' or gurgle, and is generally sluggish for the first 5 mins riding. Then it goes away for good, until 10 rides later...

[Chris H]

Do you mean the starter its self will not turn or it turns and the motor dont fire?
What grade plugs you got in.

[dolly_parton]

NGK CR8EIX

Isn't start cranking = engine turning? I would like to say the starter barely cranks (the engine)...

[Wrider]

Sounds to me as if your starter is weak.  If the bike is warm it has more compression than when it's cold, so it's harder to turn over.  If you have a weak starter it would do just like you're describing.

Also I know the battery is new, but test drawdown on it.  Crank the bike over for 5 seconds without turning the bike on and your multimeter attached to the battery.  If it drops below 10.5 volts, your new battery is a bad battery.