wont stay running

[blaine]

Like I stated adjust with the bike warm for smoothest fastest idle.No two bikes will have the same amount of turns.

[mobleydrew]

Ive tried 1.5, 1.75, 2.0 and 2.5 turns out. At the 2.5 turns out, as you recommended, on the pilot air screw on front underside of carb, it idles nicely for 20 seconds then stalls, like it is choking for air. (choke is not hanging up. New choke plunger and spring.) To stay running, bike must idle at about 3500. (Ive got a setting on my PDI Multi-meter that measures RPM). At 3500, the carb piston/plunger in the venturi is raised slightly, allowing the high speed jet to suck up the fuel, even though I am standing still.
I know it shouldnt be idling that high. Less than 1800 would be nice, and still stay running, although I am shooting for less than 1500. Still thinking it needs more air at idle speed.

Since someone else said 3 turns out (on the pilot air screw) worked for them, no hurt in trying.

Too bad the PO messed with the air screw at all, instead of leaving at factory specs. Bike isnt rejetted, stock air filter and pipe. No reason to have had to remove that little cap and adjust it. Should have known something was up with it since it was idling really high when I test rode it. Would have been great if the manual specified number of turns out instead of just PRE SET for my particular carb. That way I might know to look for something else.

Thanks for the continued advice, Blaine.

[blaine]

The pilot air screw does nothing above 1/3 throttle.If the bike is idling that high you have another problem that you need to address first.In order to adjust the PAS the bikes needs to be ideling at about 1200 RPM.Maybe a vacuum leak.You can spray WD-40 around boots to check for leaks.

[blaine]

I have reread the entire post & see that you checked for Vacuum leak around boots.It still screams of a vacuum leak/hose leaking.You can't use the pilot air screw to try & control the idle.It controls the mixture.That's why it gets adjusted with the bike idling warm.

[raul10141964]

Wat Cain of air filter is in it?

[spldart]

You see that little opening that the airbox allows air through to the filter?
Try and cover that with your fingers at varying degrees.
If idle climbs as you cover then it dies as you continue to choke it off then you have
air leaks. (lean)
If it just goes straight from barely wanting to idle to dead then your to rich. (overly
restricted is another possiblity)
That test doesn't work if you don't have the plug in the hose going down from the
airbox... Thus the (better test at the carb mouth comment below)

This test might be more accurate if you yank the airbox and place fingers over the
carb inlet itself.

When I used to mod to K&N filters I would test if I was still to lean by putting a cut
off sock end over the filter. If it ran better then I knew I still needed to jet up a bit.
The sock would slightly restrict airflow and a 'at throttle' lean situation would improve.

[mobleydrew]

It idles that high because I am forcing it too. I got to get it home somehow, when riding around in the neighborhood trouble shooting the performance. I turn the idle screw (not pilot screw) high to make it so. Youre right, the air screw does nothing above 1/3 throttle. Does little below too....which is my problem. Idles great for 20 seconds, then stalls. I restart and turn up idle ALOT in order to stay running so I dont have to keep blipping the throttle to keep it going.
Correct, idle screw is for adjusting mixture. Screwed in too far, not enough oxygen molecules to mix without fuel (rich). Too far out and too much oxygen will mix with fuel (lean). Since oxygen burns hotter then just fuel alone, it would idle high without touching the idle screw at all.
The problem is not the high idle, since I am forcing it to idle high. Problem is stalling at normal idle setting because it is NOT getting air. If I had air leaks, it would be idling high on its own without adjusting the idle. Spraying engine starter fluid all around intake boots, all over carb (both sides) and up the idle jet adjustment hole (to see if rubber o-ring is sealing properly) has no effect.
Could it be that the pilot adjusting screw is not the culprit, but the pilot jet itself is not allowing enough fuel through? Perhaps it is SOOO lean that engine is overheating, which explains why it wont restart until it cools off.

OE air filter, it looks brand new. Could the puddle of gas, that was found in the bottom of the air box, produced enough fumes to cause the air filter to deteriorate to a point where air no longer flows through it efficiently? (I think the PO left the PRI on overnight before I bought it, since the oil smelled like gas and was really thin when I changed it.)

[mobleydrew]

Maybe I should start over......
Hey guys! I start my bike. It runs and idles great for about 20 seconds then it cuts off. I try to restart it and it wont, regardless of using the choke or not. It just cranks and cranks without even a sputter. I will go out to bike after a few hours, starts, runs great, stalls, wont restart.
Why would it do this?
(keep in mind, I have rebuilt the carb. new choke plunger and spring)
Mentioned in previous thread. Since it starts fine after engine cools....perhaps it is running too lean, causing it to overheat, and I need to check the pilot jets themselves.

[spldart]

I may be wrong but it sounds like your float isn't set right.

Gas in airbox.
Once you start bike and the petcock gets vaccum to allow fuel flow you flood out....
Unless revving motor which keep the f/a mixture close enough to proper range to burn.

I dunno. Other stuff could cause this.

[raul10141964]

Inspect the spark plug , black =rich white=line


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