Starting was getting harder. (apparent solution)

[spldart]

When I picked up this bike 10 weeks or so ago, i don't remember dates, it wouldn't
crank and wouldn't start when jumped.

Flat battery and carb rebuild later I got a pretty nice running bike.

Starting a couple weeks ago it started getting real hard to start when cold. I was
worried the low compression was the culprit but had other suspicions too.

Yesterday I was idling at a light and the engine slowly slowed down from it's idle
speed of 1500 rpm to stall. Not like you kill it... It just idled down slowly.

So I'm thinking. That almost seemed like I ran out of gas.
I hit the starter button and it sparked right back to life and continued idling normally.

Brainstorm brainstorm.

Next morning I don't leave the fuel in the on state but instead in the prime state.
Then set the choke full and cranked.... Instant fire.
Hrmmm....

I head to work in prime, kill it, and set the petcock back to 'on'.

Time to go home. Set to prime, full chock, instant fire. *interesting*

I'm thinking either the diaphram in the petcock is leaking or the vacuum line is
leaking and the carb is not getting enough gas.

Otherwise the motor runs perfect.

I'm gonna get a new vacuum line and new fuel line for the bike.

I also now need to rebuild the petcock valve as it is now leaking real slow from
my constant switching. It is 15 years old and was sitting in the same one position
for many years.