1993 federal model
The bike has died on me several times, just sputters out like its not getting fuel.
I thought for sure it was the fuel petcock so I replaced that with a brand new one. Went on a ride yesterday, died on me twice at highways speeds (6K rpm). It then refuses to start for about 2 minutes but eventually turns over while turning the throttle. Maybe its starved for fuel, maybe its flooding with fuel? Maybe the petcock isnt getting vacuum?
Any tips on what I should check next? I'm planning a 200 mile ride next month and I'd like a bike that doesn't just suddenly die on the highway :oops:
re-check your fuel lines... mine were crossed up when I got my bike... sounds like the same situation as I had.
Could be possible that your ON line is accidentally connected to you RES line or really any other combination.
There are a few threads going on about this.
Here's a quote from another post...
QuoteMake sure all lines are hooked up properly:
http://img.photobucket.com/albums/v443/jcp8832/01-02fuelcock.jpg
http://img.photobucket.com/albums/v443/jcp8832/04-06fuelcock.jpg
http://img.photobucket.com/albums/v443/jcp8832/89-00fuelcock.jpg
MIGHT also be a good idea to check if the fuel switch under the tank is FULLY on ON. This one's just a thought.
+1 to LOUIE and:
Most of the ideas in you OP are where you should start. First just make sure that you have gas in the tank, flip it to prime when it starts to see if that remedies it, check the vacuum to the petcock if the prime thing helps.
Also check your hose routing:
http://www.bbburma.net/FuelHoseRouting.htm (http://www.bbburma.net/FuelHoseRouting.htm)
and the float heights:
http://www.bbburma.net/FloatHeight.htm (http://www.bbburma.net/FloatHeight.htm)
The carbs may also need a cleaning could have bits of rust/dirt in the jets...check the inside of the tank with a flashlight for rust and try draining the bowls to see if any crap comes out.
Hope that's a good start :thumb:
Keep us posted
I was rather careful with the routing, I'm fairly sure I did it right, used this as a guide
(http://www.bikemandan.com/stuff/www_gs500_de_HoseRouting.jpg)
what do your plugs look like?
Although it's normally a problem for continuous driving in high revs, your description matches it.
Try the petcock on PRI.
According to what happens there are several possibilities, but you've got one starting point. I'll try to get that page translated later, maybe google translator helps in the meantime: http://www.gs-500.info/index.php?title=GS_geht_nach_Vollgasfahrt_aus
As I said, the problem described on the page normally occurs when you go flat out for some time - your description (spluttering as if no petrol, takes some time until it restarts) does match on the other hand.
Are you sure there's enough fuel in the tank? I suggest filling the tank before proceeding with further testing.
Haven't pulled the plugs yet, will do that
I topped off the tank before this trip, there is fuel in there
theGrinch: My first thought was the petcock and thats why I replaced it with a brand new model. I think what you're describing is a faulty petcock with a bad vacuum diaphragm, my new one obviously wouldnt have this problem. But if its still not getting vacuum from the carb, that could be an issue. I dont know how likely that is though
Check the tank vent. If "2 minutes" becomes "a few seconds" when you pop the gas cap while sitting beside the road, that's a likely suspect.
http://gstwins.com/gsboard/index.php?topic=41061.0 (http://gstwins.com/gsboard/index.php?topic=41061.0)
As for bad vacuum, despite all the hand-wringing about the prime passages being smaller, they will normally flow plenty of fuel to verify if the problem shows up when you run the bike in prime, or not.
Quote from: dwoloz on August 11, 2008, 10:58:25 AM
1993 federal model
What is a "federal" model? Does this mean it is restricted somehow?
...not California. A 49-stater. Hasn't got all the ha-ha-ifornia emissions control junque on it.
You've replaced the petcock, but what about the old vacuum hose? May have a crack/pinhole.
Just translated it, might have some helpful points for you: http://www.gs-500.info/index.php?title=Dies_whilst_riding_at_full_throttle
(If anybody has any better words for the technical stuff (i.e. float needle valve), please let me now.)
The Grinch's last link should go in the Wiki, its a great aid for troubleshooting the fuel system. Thanks G!
Quote from: the mole on August 11, 2008, 02:31:41 PM
The Grinch's last link should go in the Wiki, its a great aid for troubleshooting the fuel system. Thanks G!
I just did the translation, the knowledge is from AmigaHarry ;)
We have a cooperation between the US wiki and the German one, feel free to link it.
Thanks for that translation!
This problem has happened before in PRI (this was prior to the petcock replacement).
This caught my eye:
QuoteIf you park the bike, you should swith the petcock back to ON, otherwise the carbs get flooded if the float needle valve is broken (not a rare fault).
When I first bought the bike I didn't realize the valve was in prime (from the previous owner) and left it that way overnight. The garage smelled of gas the next day. Switched to valve to on and the smell was gone. So I suppose this means I have a bad float needle valve?
Possibly - which in turn might explain your starvation problem!
If you're brave you can see if you can reproduce the smell by leaving it on PRI overnight again - but you wanna make sure the airbox drain works, otherwise you flood your engine and ultimately the oil with petrol -> not a good idea.
If you have excluded everything else, a carb clean and possible needle replacement is in order. If you don't fancy doing it yourself, somebody on here was offering it. (was it the buddha?)
So, here is what I have checked so far:
Fuel routing is correct
All lines secure, no leaks
Air filter was just replaced
I shined a flashlight in the tank, looks very clean, no rust. Filter looks fine, can't see anything really on it.
Pulled the fuel filler assembly, took it apart, looked pretty damn clean already, someone probably did it before. Cleaned it up anyway. Put it back together after much frustration, probably screwed it up more than what I started with, doesn't work the same anymore, bah. Vent is definitely clear though
Checked the float heights using this method http://www.bbburma.net/FloatHeight.htm and the non driveside carb is fine, the driveside carb's level is about .5in above the gasket line. Don't know if this is enough to screw with things but its definitely off.
Pulled a plug, doesn't look bad at all. Heres a picture:
(http://www.bikemandan.com/stuff/IMG_2830-1.JPG)
Wanted to check vacuum on the line leading to the petcock but theres no easy way to get at it without taking off the tank and I was far too lazy to do that.
I need the bike to commute on for school that starts the 25th so I really just wanted to have a shop look at it and fix it but nope, thats not even an option, all the shops in town are booked solid for the next 2 weeks.
Quote from: DoD#i on August 11, 2008, 01:14:18 PM
...not California. A 49-stater. Hasn't got all the ha-ha-ifornia emissions control junque on it.
Ha, I'm in PRK (Peoples Republik of Kalifornia) and I don't have any of that junque on it either!!!!!!
Check the vent hose from the t connector for blockages
kinda sounds like flooding have you cleaned the carbs latly? check the jets and floats
What exactly does "cleaning the carbs" entail?
I've never dealt with carbs in my life
I the float height is off on the driveside carb by half an inch, the other carb is fine
Just took her out for a short 8 mile ride through the city; didn't go over 45mph
Absolutely no problems, ran fine. Gave it just a tiny bit of choke for the first couple minutes and that was it.
By the end of the ride idle was a bit higher than normal, 1500rpm instead of 1200.
Next ride I'll do some freeway riding to see if it only happens at high speed (although I loathe the thought of dying again in 70mph traffic)
Died on me again!!! ARGHHH
This time, 40mph, 4k. Prior to it finally outright dying, it would lurch, power surge, etc. I would be cruising at a constant speed, I'd feel power drop, then return, then drop, then return. RPMs would stay steady but I felt it lurching and hiccuping
Tried to start it about 4 times but then it stopped cranking, battery was out. Previous times it was able to attempt to crank way more than 4 times, not sure why the battery was so weak.
Coincidentally it died in front of a motorcycle shop of all places :o The guy there was able to give me a jump and I was back on the road.
2 miles later I felt the power lurching again. For the hell of it I reached down and turned it to prime. Can't say if that prevented another die out or not but I didn't die the 6 miles after that.
THIS IS SO FRUSTRATING
You said that you checked the hoses, no kinks anywhere right?
Pull both plugs to compare them...this should give you a good idea of whether one carb is providing more fuel than the other. A cleaning and synch might be in order. Mine were out of synch with crap autolite plugs of too hot a heat range and I had very bad surging just not dying.
I know that I will hear it so if you do do a synch a valve adjustment should be done beforehand.
Did you check that vent hose? I had a similar problem tou you and it was because a wasp built its next in the vent pipe.
Also have you tried a fresh batch of fuel?
Hey what's the latest on your dilemma?
I've been having the same problem on my '93 too!
My right cylinder plug looks fine but the left plug continues to show it being carbon fouled.
Sounds like vaper lock to me. next time it does it as soon as your on the side of the road with helmet off open your gas cap see if it makes a sucking sound.
crap i just made a thread similar to this, guess i should have checked first.i'm gonna try a few options that have been offered here and see if that helps at all.......
so.....any progress?
I had the exact same problem and have worked it through to the point that I know whats wrong with "My Bike". Heres what ive figured out.
MY FLOAT HEIGHTS WERE TOO HIGH !
My problems were the same, the bike would instantly loose power at a steady throttle. My plugs would foul in about 3 miles. I started carrying spare plugs and an 18mm wrench when i left the house to get me home. Checking the float height with the bike on the center stand so the bike is level, i used the tube method and they were both high, left .25" and right .5" above the float bowl gaskets. You will need to learn these carbs and familiarize yourself with there construction and assembly to keep service cost low. The GS is notorious for float heights rising even when new so reset those first. That helped my my performance tremendously.
Keep in mind these carbs, even though connected, both act independently and can very the amount of fuel if there are differences between them, ideally they should act the same.
If the jets are clogged or any passages are gummed up that impairs fuel delivery. Clean them one at a time, so not to loose any pieces or mix them up, w/ aerosol carb cleaner and a small brush and thin wire. After the float heights were set properly and the carbs cleaned thoroughly, the right cylinder plug would still foul, but get me about 100-130 miles before it would be clogged with carbon. By this point, I was pretty confident with my carb rebuilding skills but found the air/fuel mixture screws. There is one on the underside of each carb, close to the spout to do the float height check. They come covered with brass caps from the factory, but mine were removed by the previous owner. These are set at the factory and usually are not to be adjusted unless doing aftermarket performance air filter and exhaust mods.
My right carb air/fuel mixture screw has been tightened beyond its limit and has stretched the aluminum part of the carb body that it fits into to regulate the amount of fuel its letting in at idle.
By adjusting the right side only i have eliminated the plug fouling all together.
Best scenerio, clean the carbs, set the float height, change the plugs (no matter what, its like $4), if there are brass plugs on the air/fuel mixture screws leave them alone. I would then change the oil and oil filter to be sure that no fuel has contaminated the oil.
If you think its your mixture screws after none of this works, tighten them all the way down( but just until they seat, do not over tighten) and then twist them out to stock, 2 and .25 turns. Then move in .25 turn incraments out to add more fuel to the mix. If there closed , no fuel..............open up more, more fuel. but this adjustment only affects the bike at idle so performance should be quite well with all other previous cleanings and procedures.