Motorcycle Repair: Honda 250 wont start when warm, honda 250cc, honda 250

Question
My friend Pat has a older Honda 250cc 4stroke air-cooled street and trail bike that he got not to long ago that won't start once the motor is warmed up and shut off.  There are 2 things that we found out on the bike that are weird.  First we don't know what model it is.  Its not marked anywhere on the bike.  We even had a Honda motor head tell us that he never saw that bike before. The second weird thing is that it has two carbs and two exhausts but only one cylinder?!  The motor has been rebuilt and runs fine as long as you don't stall it; if you do then your pushing it home. We just don't know what to do about it.  You can kick your guts out until the cows come home but it won't start until it is completely cooled.  It idles and runs at any rpm just fine so we are at a bit of a loss.  Please help!

Answer
Hi Steven,

Check for defective ignition coils. I suspect excessive resistance within the windings when the coils get up to temperature.

The problem may also be: ignition timing too far advanced, carburetor out of adjustment (lean), or other.

You should try and contact AllExperts- Bill Silver. He's the pro with older Hondas. Bill's authored several books on Hondas.

I'd love to see images of the engine and MC in general. Can you send images? If so, send them to me at:

mshively1@woh.rr.com

Respectfully,
Mark Shively