So I finally got around to cleaning and reinstalling the carbs, put in new spark plugs and hooked up the car to jump the battery.  I made sure the tank petcock was set to on, set the frame petcock to prime and waited for about 60 seconds.  Turned the frame petcock to on, and pushed the start button.  Bike cranked and cranked but never caught or turned over once.  Then I noticed fuel coming out of the airbox drain tube and leaking on the floor.  It was dripping slowly, but after about 2 minutes it stopped driping alltogether.

Can anyone suggest why this might be doing this, or why it won't start?

Thanks,

Nick

did you check for spark? unhook a plugwire, remove that sparkplug, position it so that you can see it and it is touching motor, and crank bike over while watching the plug.  if you have fire on both cylinders, I would squirt some carb cleaner into the carb inlets and try again

Sorry I've emailed this to like 10 people and instead of copying I keep retyping so I forget what I have and haven't said.

Yes I checked for spark and it was STRONG, and BRIGHT, and BLUE.  Spray carb cleaner where?  I have the airbox on, so should I take the filter out and spray it in there?

Also, I have been using "brake clean" on the metal parts that needed cleaned not "Carb Cleaner".  Would that be the same to spray in there?

Thanks,

Nick

OK, fuel leaking out the airbox drain means your carbs are over-full.  The bike won't run, it is flooded.  You need to take the airbox off, then open everything up to prime, etc again, and observe.  One or both of your carbs are overflowing.  This is casued by the needle not seating.  THere could be a cause or 2.  One is that there is debris in the area, causing the needle not to seat, the other is that your float level is off.  Well, you could have left the needle entirely out of the carb, but let's assume you didn't do this  (or not     )

If you can isolate the offending carb, then take them both off & check the float level of the leaker.  If it is OK, then re-check the needle & seat to make sure they are A-OK.  I'm not sure if these floats have a tendency to go bad or not, but if you take it apart & the float itself is full of gas, that's it.  I'd double check the non-leaker as well.

The carbs really are pretty simple, just get out your clymer manual & double check everything.

Good luck!

John.

You know, I wasn't 100% sure I was setting the float heights right, and one of the needle jets I was iffy on replacing it.  I am 100% sure I didn't leave out anything in the carbs lol but good thinking.

So I just checked and the carb on the left side of the bike had about 2.5 - 3 ounces of fuel that I drained out of the float bowl and the right carb was completely dry!!!

Thought of another thing not standard.  I installed a fuel filter on the hose going from the frame petcock to the lower T of the carbs.  I double checked and the fuel flow is going the correct way, however not sure if that is the correct line to have the filter on?

Thanks,

Nick

So I went and did some more checking, and the left side carb (the one that had gas in the float bowl) is the one leaking gas into the air filter box.  I took apart the right side to see why it was dry, made sure everything was clean, reassmbled, and its still not getting gas?!

I'm still wondering if this float needle would be the cause (left image large to show the wear, sorry):



would this not seating right be the cause that the carb is not getting fuel?  I would assume this would cause a leak since it won't seal right being worn down?  The left side carb is not like this yet its overflowing with fuel!




Would the float height being set incorrectly be the cause of the left carb overflowing?  Is there any other alternative I should also check causing it to overflow?  Sorry for all the questions, I'm still learning carbs.  They really aren't that hard to take apart, its just getting them to function correctly that is a P.I.T.A.!



Also, the pilot jet *I THINK ITS CALLED THE PILOT JET* is pretty difficult to get in and out.  Its pretty damaged after removing them twice yet still seem clear and not clogging anything (again sorry for the size, enlarged to show the damage):




Thanks,

Nick

I'd deffinately replace those jets and check float level. Use the clear tube method outlined in the how to's

problem is, being unemployed at the moment I can't just go out and buy new stuff if it *might* be the cause of my problems.  I need to know for sure and be justified in spending ANY more money on this bike.

Thanks,

Nick

I believe you can buy some singles from buddha. or if you can wait a week or two, i will be able to send you my stock jets for a few bucks.

The corrosion might be a factor.  How did the needle end look?  How about the seat? Do they ride up & down smoothly? 

I'd change those jets.  You can see the little chunks of metal just waiting to clog some ports in your photos!  Yours is an early bike, right?  I bought everything to jet mine, but it was already done.  For $10, I'll send you 2 new pilots, mains & the stainless washers to put under the needle.  They are gathering dust here...  They are the 40's & 127.5's, or whatever you use for a K&N.  I think stock filter is the same too.  Check the WIKI to be sure...

i have this exact same problem down to a T (left carb and everything).  I'm waiting on a new needle valve to hopefully fix it.


looking at your pics, your needle valve is super worn, should replace that.  You shouldn't be able to see a groove like that.

the valve and seat are $30ish from bikebandit.  Or hit up Buddha... I'm doing the same thing.

Quote from: JStrube on May 17, 2009, 10:05:45 PM
OK, fuel leaking out the airbox drain means your carbs are over-full.  The bike won't run, it is flooded.  You need to take the airbox off, then open everything up to prime, etc again, and observe.  One or both of your carbs are overflowing.  This is casued by the needle not seating.  THere could be a cause or 2.  One is that there is debris in the area, causing the needle not to seat, the other is that your float level is off.  Well, you could have left the needle entirely out of the carb, but let's assume you didn't do this  (or not     )

If you can isolate the offending carb, then take them both off & check the float level of the leaker.  If it is OK, then re-check the needle & seat to make sure they are A-OK.  I'm not sure if these floats have a tendency to go bad or not, but if you take it apart & the float itself is full of gas, that's it.  I'd double check the non-leaker as well.

The carbs really are pretty simple, just get out your clymer manual & double check everything.

Good luck!

John.

oh..... and what John here says is pretty bang on!


oh and another thing... check the diaphram for cracks/holes.  A pretty easy way to do it is to leave the carb assembled and push up on it with your thumb.  If it returns good and smooth your diaphram is good.  (compare it against the carb thats working good).

ok, well the leaking carb (left carb) is the one with a good needle valve jet so I'm assuming then that I've incorrectly set the float height.  I've read wiki, and my clymers manual and I'm still not following how to set these correctly.  Using this from the wiki:

http://wiki.gstwins.com/index.php?n=Maintenance.FloatHeight

Can someone explain what I am to look at for the float arm to be just in contact with the needle valve? 

I'm going to be tearing into the left carb to see if the float height is off causing it to leak into the airbox.  None of the diaphrams have any damage and everything else looks great.  What would cause no fuel to be in the right carb?

Quote from: LOUiE on May 18, 2009, 09:54:29 AM
i have this exact same problem down to a T (left carb and everything).  I'm waiting on a new needle valve to hopefully fix it.


looking at your pics, your needle valve is super worn, should replace that.  You shouldn't be able to see a groove like that.

the valve and seat are $30ish from bikebandit.  Or hit up Buddha... I'm doing the same thing.

I missed this in the photo.  Your picture isn't the jet, it is the needle valve, the "seat" part, right.  You called it a pilot jet...  Yeah, your needle won't seat on that thing, replace it.

I was refering to the second picture when I called it a pilot jet.  The first picture with the worn seal I referred to as a needle valve jet.

Its a float needle and yes that pointy look = bad. Not bad enough to not run especially if you put it in prime just a second of so before you start it, it should get started and run ... till it starts to choke up on the fuel and leak and die ... leak before die too ... in fact you could ride it home if you were 50 miles away and at WFO, it would run almost fine. It would empty your tank in that distance though.
Pilot jet - yea its boogered. If I wasn't mad at you, I'd be tempted to send you a pair of stockers for the cost of a stamp. OK fine screw you ... send me stamp $ and an address. I got a perfectly good 20-30 of them.
Cool.
Buddha.

Oh, on a dry bowl it will not start. An overflowing bowl it will start but run farting and crappily till you get it revved into the higher rpm.
And I meant pilot jets, not float needle.
Cool.
Buddha.

Quote
I'm going to be tearing into the left carb to see if the float height is off causing it to leak into the airbox.  None of the diaphrams have any damage and everything else looks great.  What would cause no fuel to be in the right carb?

got some shyte in there blocking flow?