Topic: vapor lock???

[75cb550 (kyle)]

okay, the bike has been running good. took it down to the store today and she ran fan. got back and parked it for about 30 min. went back to fire it up and there's no fuel in the filter. pulled the gas cap. its full. finally pulled the fuel line from the petcock and it his and started filling up the filter. let it run for a bit and it would suck in some fuel as i revved it a bit. let it run some more and it ran out of fuel.
so long story short, its vapor locking. the hose to the filter is clear.
also, probably important... is a brand new tank and petcock.

so im think that the carbs are vapor locking somehow... any thoughts?
thanks

[Ayrity]

you checked all the big boys to cause trouble in that area I am guessing? pop open the tank cap in case youre making a vacuum? made sure there are no kinks or loops in the fuel line(s)? After those, I would guess it would be time to see if your floats are adjusted well, and that you dont have a float that is filling with gas... though I dont know why that would effect the entire fuel line. are the filters new/clean? might be worth it to pop a new 2 buck one of there from the auto store.

[75cb550 (kyle)]

yeah. stuck a different filter i had on the shelf in and it is fine now... i had one of the cheap cone autozone filters. i stuck a big cylinder (?) shaped one in and no problems....
seems strange to me but ill go with it... it ran for about 20 min just fine


thanks again
crisis averted. for now.

[Steve F]

BTW, if I'm not mistaken, vapor lock can only happen on engines with fuel pumps.  The fuel boils in the fuel system and vaporizes, and the pumps can't pump vapors, so the fuel flow stops.  Wait for the system to cool off, and fuel returns to liquid and can then be pumped.

[75cb550 (kyle)]

air lock then.. apologies

[Steve F]

Ah, no worries.  I had problems with the fuel line routing, and just had to be sure there were no up hill runs from the tank to the carbs.