Starting issues when hot. What do you think?

So today i went to a bike show, and on the way, after about a 45 min driving i stopped at mcdonalds for a minute. I go to restart my bike(kz550) and the starter is really slow and working hard. I couldn't get the bike started. With the help of my friend we push started it pretty easily and it ran fine all the way to the show. After the show it started fine cold. I drove back home and shut the bike off and tried to restart the motor and it won't even turn the motor over. I let it sit for about an hour or so, and it started right up.

What do you guys think the problem is? I'm thinkin starter motor.

It hasn't been much of an issue because i mostly use this bike for comuting back and forth to work which is only about 15 minutes. today i rode it about an hour sraight.

Thanks for the input.

I'd check the valve clearances, tight valves let out compression and make starting more difficult. As metal heats up it expands reducing the clearances. Fresh,properly gapped sparkplugs with the correct heat range helps too. I'd also check the sparkplug ignition leads, and sparkplug caps.

Today i took the bike to work, in the morning it started fine but when i went to go home the starter turned the motor over for a few seconds and then did nothing, only the solenoid would click. I waited a few seconds and tried it again and then it turned over the motor and it fired up. When i got home i pulled the plugs out and tried to turn the motor over but the solenoid just clicks. I cleaned the connections to the battery and the solenoid. I ran out of time but tommorrow i think i will check the ground wire to the engine.

Thanks for the reply Mfolks but i am confident the valves clearances are ok because i did that only a couple thousand miles ago.

I took the starter off and then hooked up a ground and hooked up the positive wire. The only way i could get the starter to turn was by first manually spinning the then it would take off. I took it apart and it is toast inside! Smelled very burnt. So i think i found my problem. Already ordered a re-manufactured one off Ebay.

Can't wait to get it!