Fuel POURING out of airbox drain.

[Winterstein182]

Hi everybody! Can you help? I just bought an '82 GS650 GL and it has a severe fuel drip. Since I bought it a couple months ago it would only run on Prime. That is still the case but now as soon as I turn to Prime gas flows out of the airbox vent so fast and at such a high rate you can hear it running through the carbs! Also, the bike wants to rev to 5k rpm or more at start-up. I've got my guesses from reading on this forum, but has anybody else seen this MUCH overflow and...what happened? Great forum BTW!

[Larry D]

Welcome !!

Buy and install a new petcock. Remove your carbs, dissassemble, dip, and install new o-rings.
Also, more than likely you have gas in your crankcase, so, do not run the bike until these items are addressed and you have changed the oil and filter.

[still_bluenoser]

Float needle stuck.

[chuck hahn]

Petcock IS NOT the issue...I am going with stuck float needles also. Tap on the bowls and see ifm it stops. If so, you know the problem. Next, tear them down as suggested and see that there is nothing stuck in the float seats. Physically watch the float needles to see they rise and fall as you move the float up and down.

[mike_of_bbg]

I just bought an '82 GS650 GL and it has a severe fuel drip. Since I bought it a couple months ago it would only run on Prime.

Petcock IS NOT the issue...

Sounds like there's a petcock issue to me! Granted, the fuel out of the airbox is likely a stuck needle valve, but nonetheless, the petcock should function on ON and RES as well as PRI. Check the petcock vacuum line to make sure it's hooked up (if not that's a big vacuum leak and could cause the engine racing) and that there's no fuel in it.

Full carb rebuild and new petcock in order, methinks.

Also, the "choke" on these carbs is actually a "fuel enrichment system", which when open allows an enriched mixture of fuel and air to the cylinders. As the motor warms up and each cylinder kicks in the RPMS will rise on choke. I tend to feather it off and try to keep the RPMs around 2k for a minute until it's warmed up.

If you have high RPMs with the choke off, you have an air leak somewhere. Petcock vacuum line and intake boots/intake boot o-rings are prime suspects.

I see this is your first post. Here's a link to BassCliff's site:

http://members.dslextreme.com/users/bikecliff/

and his greeting:

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

BassCliff is a member here that has done a fantastic job of archiving frequently needed information about maintaining our little GSes.

[BigD_83]

+1 on the stuck float needle/s being the likely cause.

If you have not had the carbs apart, you're going to need to do it eventually to see with what you are dealing.

There is a manual for the 650 on the page Mike linked for you (Basscliff's website). It will help you with sorting out the fuel lines as well if you are not 100% confident they are running to the right places on the carbs.

Welcome to the nuthouse.

[Winterstein182]

Thanks everybody. I took the carbs apart last night. Not only are they spotless but appear to be rebuilt as claimed during the sale. Floats are currently floating and needle valves are moving free. These carbs are very, very, clean. I'm going to try a petcock swap or rebuild as some people feel Prime can overwhelm the floats. I'll check everything again during reassembly with an open mind. I was disappointed when I couldn't find a stuck float or needle. Any and all opinions and ideas are welcome. Thanks!

[tom203]

Methinks, that if you gonna clean carbs (no fun). best to replace petcock and avoid this common issue while you're enjoying yourself.
I know this petcock fits a gs650....

http://www.ebay.com/itm/SUZUKI-GS450...#ht_792wt_1025

Update; do yourself a favor and just get a new petcock- unless you are really bored

[bluewool]

Only running on prime is certainly indicative of a petcock issues. Worn out needles will cause bowls to over flow, so will a very poorly adjusted floats. Someone bends a tab accidentally and it just never seats the needle; not unlikely if they we just cleaned and reassembled.

[mike_of_bbg]

I've done the "bench test" before, with my carb rack on a bench (blocks of wood holding it upright) use a funnel in the fuel line to add some gas and see which of the carbs leaks.

There are really three (non-exclusive!) possibilities:

1) One or more needle valves is not seating.

2) One or more seat o-rings is leaking.

3) The petcock is sending fuel down the vacuum line to cylinder #2.

[bluewool]

I'd agree with Mike, and add this to item 1)

For one or a combination of the following
a) worn needle
b) worn seat
c) float adjustment incorrect.

I have poured rubbing alcohol or methyl hydrate in the funnel to fill the bowls,(check for leaks and set the float height) mainly because I was in the basement or on the deck; however it makes clean up very easy also.

[chef1366]

See if you can isolate the carb(s) leaking and check and see if the float seat has a torn or missing o-ring.

[BassCliff]

Greetings and Salutations!!

Hi Mr. Winterstein182,

You'll find a lot of answers, tips, tricks, "how to" guides, and general information in the links below. Here's a quick "mega-welcome".

If you are here you probably have a 30 year old motorcycle that needs about 20 years worth of maintenance. You'll find all kinds of helpful tips, procedures, manuals, diagrams, "how-to" guides, etc, in the links below. Let's get started.

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please Click Here For Your Mega-Welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

More links to helpful threads in the forum:
Help! Your Bike Won't Start
DON'T DO THESE THINGS
Help! Your Bike Won't Run Well
Oh God! Pods!


Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[bwringer]

The petcock is very often the issue in these cases, but somewhat indirectly -- crudniks from an old corroded petcock can and often do work their way down to the carbs and prop open the float needles.

It's also depressingly common to find that the float heights are set all wrong, even with freshly cleaned and adjusted carbs.



And finally, if the carbs were rebuilt with kits, they'll be useless until you replace the random garbage from the kit with OEM parts.

[Winterstein182]

Ok, I've ordered a new petcock. I figured I should because mine was never right anyway. So...float height. I guess I'll search the forums unless someone wants to jump in with some instructions. As always, thanks for all the help and I'll take as many opinions from knowledgeable people as I can get.