Newbie with starting problem

[bluehonda]

Hi y'all, Just got a 1990 cb-1 with 9400 miles. These things are pretty neat! I do have a starting problem, the bike starts ok with a cold engine but, after it warms up it just cranks and cranks and I have to let it sit for about 15-20 minutes before it will restart. Is there a common problem that I should look for? Any advice would be greatly appreciated!

[cptseawolf]

are u using the choke on the warm start or no?

is so.....don't.

Just start it and crank the throttle just a bit while making a warm start

[bluehonda]

Choke off-- Choke on , no diff, Just cranks and cranks. let sit - starts-???

[clarkdw]

Any small of gas? Could be flooding if petcock is leaking by in which case it would be worse with a full tank of fuel. You do turn off the fuel when you shut off the bike?

Second possibility. How warm does it run? If fairly hot it might be boiling off the fuel in the carbs and vapour locking. If fuel boils off the carbs take a lot of cranking of the engine before they fill up because the fuel pump only works when the engine is sparking ie: either turning over or running. Doesn't pump when only the key is on.

Because it is temperature sensitive the most likely culprit is the fuel supply with some odd electrical gremlin a distant second choice.

[Drewski]

Might be worth trying a new set of plugs, if you havn't already. You'll need the right size spanner. Then, as above, no choke and a tiny amount of throttle. If no use, maybe your choke is sticking on a bit. To get in and check, you'll need to take the tank off, then the air filter box and just check that  the choke lever is returning properly on the carbs when the lever is in the "off" position.