fuel running from airbox vent hose

[Guest]

I took Shelah out for a ride to do some errands after work since the weather was nice and decided to stop and eat at 5 guys. As I'm finishing my soda out side and getting ready to head home I notice a pool accumulating under her, at a fairly quick rate. Natural course of action was to investigate, and turns out it's fuel. As I'm looking to see where it's coming from, which was the right side of the bike which didn't make sense at first, I find it leaking out of the airbox vent hose. What would cause this? bad o-rings on the float valve seat? I have Shelah on her center stand with my catch pan to see if it was a freak-ish happening, or if it's something I really need to check out like now-ish. I'm gonna check in Shelah in abiut an hour or so and see if it accumulated any fuel

[Nessism]

For one thing, either your petcock is set on prime or it's failed. There shouldn't be any fuel flow when the engine is turned off.

Secondly, either your float needles are weak, crud fouling the float needles, or fuel is running backwards down your petcock vacuum line and back into the carbs causing them to overflow.

Thirdly, what's up with naming your bike? I'm embarrassed for you.

[60ratrod]

Well someone has to be embarrassed. Anyway, she sat on the center stand for an hour and a half and not one drop so far. I took her off the center stand her on the side stand. We'll see how this turns out since the problem happened on the side stand. My first thought is floats/needles/o-rings since the floats should stop the fuel flow, even with the engine off in theory right?

[Nessism]

Check your petcock.

Carb rebuild tutorial linked in my signature.

[60ratrod]

Well so far so good with no fuel draining into the airbox. I'll try popping the line of the tank tomorrow to see what happens. And the carbs are getting a full tear down this post season, along with other things like oil change, valve adjustment, clutch kit, and paint job with possible indicator light upgrades. I'll update tomorrow with what I find. If it's not the petcock then I'm gonna check the floats by doing a level test. Too bad the bs32's don't have bowls like the bs34's do.

[Shawn68z]

Had the same issue with my 650 when I first got it. Even after the carb rebuild I would get a little gas the drain tube. Once I re-synced the carbs the problem went away.

Shawn.

[60ratrod]

Ok, so the problem came back, after making my house smell of gas from leaking out the airbox drain again.   I looked into the problem and the petcock was on prime and wouldn't stop running in the on position. So I took the petcock apart and cleaned it.  It works properly now.  After filling the tank and trying to go down the road I found a really horrible low end stumble in all gears.  So I changed the filter and no change.  I yanked the carbs and they looked ok.  But I did notice the filter had some stuff in them and some rust developing in the tank.  Am I due for a cleaning before the end if the season?

[Steve]

Too bad the bs32's don't have bowls like the bs34's do.

I don't understand this, because they are identical.

.

[60ratrod]

Really? Are they interchangeable?

[Spyderman]

start from scratch do all the maintenance
do the valves
rebuild or replace fuel petcock
clean & sync the carbs
change the oil
if you do all of the above then your problem will go away

[60ratrod]

Well I stripped the carbs down and gave them a bath in my sonic cleaner and she runs as good as ever now. This should get me through the rest of the season. It looks like the tank is gonna need a good acid cleaning

[60ratrod]

Scratch that. It's back to acting fuel starved. I think my season is officially over for the year. I guess i'll be getting a head start on all my plans of indepth inspections and maintenance

[81GS850]

More than likely crud from the fuel tank. I had the same problem. Put an inline filter in. Good insurance in either case. I used phosphoric acid to clean the tank of rust which is a concrete cleaner found at Lowes or Home Depot. I left it bare because I didn't like the idea of tank sealer. There's horror stories all over the net and I don't personally want to find out.

[60ratrod]

Bd part is I do have an inline and I think crap is still getting past it. It's one of the ones with the bronze/brass balls. Anyone have a recommendation for a different/better filter?

[81GS850]

I used the general plastic paper pleated filter you get for like $1.50 at any parts store. I don't think the sintered bronze will catch it all.