lt 80
#1
Hi I am new to this site so I hope this Is in the right place.
I aquired a 91 lt 80 I rebuilt the top end put a new carb and a new petcock on it It starts right up and runs great until I hook the vacume line to the fuel petcock, what is the problem? bad petcock why do I need vacume to the petcock?
I aquired a 91 lt 80 I rebuilt the top end put a new carb and a new petcock on it It starts right up and runs great until I hook the vacume line to the fuel petcock, what is the problem? bad petcock why do I need vacume to the petcock?
#2
did you replace the petcock with a stock vacuum operated one?
sounds like the carb is flooding and getting extra air from the vacuum hose to help lean it out, when you plug it into the petcock, there is no air to overcome the fuel. just a guess without seeing it, but make sure the float needle is in good shape and if your float is adjustable, adjust it properly, IF your float has a plastic tab DO NOT try to tweak it, trust me, i'm THAT guy that figured i could get a little play out of it lol
sounds like the carb is flooding and getting extra air from the vacuum hose to help lean it out, when you plug it into the petcock, there is no air to overcome the fuel. just a guess without seeing it, but make sure the float needle is in good shape and if your float is adjustable, adjust it properly, IF your float has a plastic tab DO NOT try to tweak it, trust me, i'm THAT guy that figured i could get a little play out of it lol
#3
Welcome to the forums Mr.Frederick.
I've seen ppl install the lines backwards.
Just in case: closest port to motor= vac. Middle brass= fuel supply. Frony port= carb vent.
The stock petcock has a fiber valve in it that closes the fuel supply off till the motor creates vaccum and opend the valve and lets the fuel flow.
On is off till motor is turning/making vaccum. Prime lets fuel run constant.
FYI: Other on/off petcocks fit. I utilize a inline fuel filter and a on/off valve (about 10 bucks at autozone).
Hope that helps a lil.
"i'm THAT guy that figured i could get a little play out of it lol"
LMAO!!

I've seen ppl install the lines backwards.
Just in case: closest port to motor= vac. Middle brass= fuel supply. Frony port= carb vent.
The stock petcock has a fiber valve in it that closes the fuel supply off till the motor creates vaccum and opend the valve and lets the fuel flow.
On is off till motor is turning/making vaccum. Prime lets fuel run constant.
FYI: Other on/off petcocks fit. I utilize a inline fuel filter and a on/off valve (about 10 bucks at autozone).
Hope that helps a lil.
"i'm THAT guy that figured i could get a little play out of it lol"
LMAO!!





