Carb problem

[Mr. Clean]

OK just took the new 771 for a quick spin around the block. It has an insane amount of power but I'm havening a problem with the carbs. It will start and idle fine but after about 5 minutes it dies and won't restart. If I turn the petcock to Prime it will start up and run again with no problems. While I was riding it for about 10 minutes it did it again. I think it is running the bowels dry. I checked my vacuum line and there is no problem. I checked the fuel filter nd fuel lines, no problem there either. What would cause the bike to suck the bowels dry?

[Range]

sounds like starvation...check your fuel filters or a kinked line

yopu are obviously using fuel faster then it can refill the bowls!

[rotary13b]

When the bike shuts off , open your fuel tank and see if u hear a sound like vacum, venting. If u hear it your tank is not venting which means the fuel will not flow in the on position. Check your vent hose.

[KatDan]

could the float height be way off?

[The CyberPoet]

Fuel starvation.
The 771 kit from WiseCo ups the compression ratio as well as the displacement, so it sucks fuel at a very aggressive rate compared to the stocker. You may need to reset your float heights, as suggested by KatDan2, to help compensate for the added draw.

Oh, and if the fuel filter isn't facing perfectly downhill, it could be the issue.

Q: Does it do it strictly at idle?

Cheers
=-= The CyberPoet

[Mr. Clean]

No Cyber it doesn't do it strictly at idle, it did it while I was riding as well. I'm going to mess with the float height when i get off work Monday. I was leaning that way and was hoping someone else would suggest it. I'll try what Rotary13b suggest first, because pulling those carbs on and off is a PITA.

[The CyberPoet]

No Cyber it doesn't do it strictly at idle, it did it while I was riding as well.

I had stated the question poorly -- does it do it consistantly at idle? Five minutes is just about the amount of time the fuel in the bowls takes to burn through at idle when they're not receiving any additional fuel, such as disconnecting the fuel source at the petcock completely.

Good Luck!
=-= The CyberPoet

[Mr. Clean]

OK thta makes more sense, LOL. No it doesn't. It runs fine for about 5-8 minutes, dies. i restart it with the petcock in prime and it runs fine after that. Even if I turn the petcock back to normal.

[The CyberPoet]

OK thta makes more sense, LOL. No it doesn't. It runs fine for about 5-8 minutes, dies. i restart it with the petcock in prime and it runs fine after that. Even if I turn the petcock back to normal.

Hmmm... that makes little sense, unless it's not getting a chance to have enough time to empty the bowls after you switch it back to normal. Hold it, yes it might -- the one situation that would satisfy that: insufficient vacuum at idle in the connection to the petcock (but sufficient off-idle), such as a pin-hole leak in the vacuum line to the petcock. Maybe that's the ticket. Well, it's a valid thought.

Cheers
=-= The CyberPoet

[Mr. Clean]

Well I think I have it ironed out now. I ended up putting in 122 main jets and setting the fuel/air mix screws at about 2 7/8 turns. I also had to put in 91 octane fuel with some octane booster.