fuel and vent lines

[luc8421]

on my 85 gs700, I have two tube outlets on the bottom of my tank, and two on the carbs, one betwen 1&2, and one between 3&4.

My manual says the two on the carbs are atmosphere vents, and the two on the tank are water drains.

currently, the 'water drains' are hooked into the 'atmosphere vents', which is how the previsous owner had it. And I'm guessing, since it's been parked in the rain a few times, that water in the gas is making it not start, I've got a strong crank and a spark, but it won't ignite.

My question is this: am I correct in my readings that the carbs tubes are vent tubes to the atmosphere, and the gas tank tubes are for water drainage?

thanks for any answers

[luc8421]

to clarify, the vent in the rear of the tank comes from the sending unit

[moto_dan]

Not exactly sure about your '85 700, but my '83 only has one tank vent. I'm guessing one of your two lines may actually route to your airbox for emmission purposes
Drain line from the fuel sending unit does not attach on the other end.
Do you have the small line from the fuel valve connected to a nipple on the #2 intake. It provides the vacuum to open your valve providing fuel flow to the carbs. The two nipples between 1-2 and 3-4 are as you noted atmosphere vents and if you have hoses on them route them up and over your airbox(some jet kits required you to leave the hoses off). Try turning your fuel valve to the P(prime) position(fuel will/should flow without the engine cranking) for a few seconds to fill your carb bowls. Also mine likes full choke for a few moments for easy starting. Good luck.

[luc8421]

sweet, well I've got a Yosh 4n1 pipe, with pod filters, and a stage 3 dyno jet kit, so I'll just leave the two carb vents open, without fuel line hooked on to them, right?
the petcock works fine, on prime or a vacum setting. I'll hook the water drain pipe down to the bottom of the frame, and
currently I've got my carbs in 13 little tuppaware containers, awaiting some new o-rings, so the test fire will have to wait.
also, there's no tubing hooked into the engine vent hole, is that going to make a difference?

[Jethro]

also, there's no tubing hooked into the engine vent hole, is that going to make a difference?

The crankcase breather hose? Nah, that dosen't make a difference. I've been running mine for years without it.