hi, i just bought a crashed gs that i had fixed up a bit and carbs rebuilt, but the guy left the old gas in the tank, it was over a year old and it was bothering me, today i removed the gas tank and dumped the old gas and filled it with fresh gas. now the motorcycle wont start and i killed my battery.What am i doimg wrong and how can i fix it? tx guys
Um, you did turn the undertank petcock back on didn't you?
Michael
Quote from: mister on November 12, 2011, 04:13:59 PM
Um, you did turn the undertank petcock back on didn't you?
and remembered to set the normal/reserve lever, to "prime" ?
^ What they said.
You need to make sure the under tank petcock slot is vertical, then switch the frame petcock to 'prime', otherwise the carbs won't get fuel until it starts and it won't start until it gets fuel = catch22. Once it starts you can switch back to 'on'.
If the battery is flat you can jump start from a car, just don't run the car's engine.
yeah, i reinstalled everything to original setup, petcock on, i didnt put on prime though, i gotta try that. im a complete newbie at this, what is prime?? thanks for reply guys i appreciate, im determined to learn and work on my own bike, worst case scenario ill take it to a shop
Also check and make sure you didn't pinch the fuel lines under the tank, it happens.
Quote from: the mole on November 12, 2011, 05:56:49 PM
^ What they said.
You need to make sure the under tank petcock slot is vertical, then switch the frame petcock to 'prime', otherwise the carbs won't get fuel until it starts and it won't start until it gets fuel = catch22. Once it starts you can switch back to 'on'.
If the battery is flat you can jump start from a car, just don't run the car's engine.
you can crank prime it but it works the HELL out fo the starter/battery. prime= easy. BTW do NOT forget to turn prime off. cleaning up spilled gas out of garage/ crank case can be a royal whore
Prime is the position on the frame-mounted petcock between On and Res. It allows fuel to flow into the carbs by bypassing the vacuum which governs the fuel when the bike is in the On position and running.
(http://farm5.static.flickr.com/4021/4448046079_237490f600_z.jpg?zz=1)
As its name suggests it is used to Prime The Carbs in readiness to be started. Mainly used for helping the bike start after winter storage or prolonged non-use. The pic shows the On position. It would be horizontal in the Prime position.
Michael
^Yes.
The GS has an automatic fuel tap when its in the 'on' or 'res' positions. When the motor is not running, the tap is off and no fuel can get to the carbs. When you start up, the vacuum in the intake is connected via a hose to the frame petcock where it moves a diaphragm which opens a valve and lets fuel flow to the carbs. When you stop the motor the reverse happens and the valve shuts.
If the carbs are full of fuel when you try to start then everything is fine, but if they're empty (due to long storage, its been dropped, or because someone drained them) you've got problems. This is where 'prime' comes in. Selecting 'prime' bypasses the vacuum operated valve so fuel can flow to the carbs even though the motor is not running, then once it starts you reselect 'on'.
Quote from: the mole on November 12, 2011, 11:59:59 PM
If the carbs are full of fuel when you try to start then everything is fine, but if they're empty (due to long storage, its been dropped, or because someone drained them)
*because it's been dropped"? !
well dang, now I learned something too! Thanks :)
(funny, now that I think about it, i was told that dropping it, FLOODS the carbs, rather than emptying them,though. how can you tel the difference?)
Phil B, whether dropping it empties or floods them can depend on the angle and force of the drop and things like whether (and in what position) and moving carb parts like floats/needles get stuck.
As far as how you can tell - if they're super flooded, it's obvious, t'll start pissing gas into the airbox and out the drain hose like it did for me recently. Otherwise - turn a float boal drain screw and see what, if anything, comes out.
oh that makes sense.
After a drop, and engine wont start
(and you've turned engine OFF, and on, to reset the safeties)
If it's dribbling out the hose , it's flooded. If hose is dry, then try using prime.
thanks for the help guys, I turned the valve to prime and it started right up, only i didnt turn to "on" right away and had a minor spill (I learned that on my own thanks to a silly mistake, but hey, im learnin right? YAMAHONKAWAZUKI i read ur post a few hours to late,lol). bike runs great. I will try to take pics as I bring the bike back to life. I changed the front forks and am waiting for a new handlebar. thanks again for the support, genuinly surprised how quick and helpful the replies were, I found this site by chance while searching for the handlebar and wow am I glad I did.