fuel starvation?

callmelenny · September 29, 2004, 08:40:06 PM

I'm in the process of trying to resurrect a 97 gs500 that sat for 2 years with gas in tank and carbs.

I have pulled carbs and cleaned them up and given the tank a thorough cleaning. Pulled the plugs also. Bike will start right up and idle. After either idling for several minutes or riding a short distance (~1mile) the engine starts cutting out and usually dies. It also won't open up, starts hesitating at around 6K rpms.

I can flip the petcock to Prime and it will start right up but surge for a while, then run ok, then die again. Running at either reserve or on both lead to the same symptoms.

Do you think my carb work was not up to snuff? Could this be a vacuum issue?

Thanks for your input, this is my first gs 500 and I am still learning the ins and outs of the engine.

R3d · September 29, 2004, 10:49:40 PM

What do your spark plugs look like? I'm having a similar problem after a shop just cleaned the carbs for me. They're being assholes now and I'm not sure I can get them to fix this. My spark plugs are sooty black, but when it dies, the bike sputters like it's out of fuel.

Not meaning to hijack - just sounds kinda like what I'm going through.

johncam4 · September 29, 2004, 11:26:25 PM

check your gas.....no kidding i cussed at mine for a whole afternoon for not running well then i noticed i was out of gas
change the spark plugs.....they will foul easily and its a cheap fix
check the fuel filter....those are supposed to be replaced ever 75000 i think
the idle adjuster and choke
i dont know much thats just stuff ive overlooked before

callmelenny · September 30, 2004, 08:31:56 AM

Thanks for the input.

The plugs looked OK but maybe I will replace them anyway.

I had read elsewhere about problems with the stock petcock and thought that might be an issue.

octane · September 30, 2004, 09:21:48 AM

Sounds like petcock vacuum. Check vacuum lines from carb to petcock, make sure there are no kinks or cracks, also check vacuum caps on carbs. If that looks good, take the petcock apart and make sure the diaphragm isn't torn, that was a problem on mine once. I've also had fuel starvation problems due to twisted or kinked fuel lines - sometimes when you set the tank down you can fold the line just enough to impede flow.

For R3d, sooty plugs usually mean the bike is running rich. The carbs probably need to be adjusted, and possibly jetted. When the shop cleaned them did they check that they were balanced, etc.?

R3d · September 30, 2004, 10:28:56 AM

LOL Thanks for replying to both of us. I can only assume the shop sync'd the carbs, etc. They're not cooperating with me at all (want to charge me to fix the work they didn't complete correctly). I'm seriously thinking of reporting them to BBB. Might have to bite the bullet and take it to a diff shop since I don't have the time to rip things apart right now. Not sure I could balance the carbs myself at this point anyway.

callmelenny · October 01, 2004, 05:53:30 PM

Let me start by saying how great this site and its members are. I have only had my GS for 3 weeks but this site has already proved invaluable.

After disassembling the carbs and changing fuel lines, my bike is purring like a kitten. Idles well and seems to run fine at high rpms.

BUT I seem to have swung to the other end of the spectrum. Now my carb overflow is constantly flowing no matter the petcock setting. I am talking about a steady stream, not dripping. It stops when I shut down which makes me think the diaphram is still functioning.

Your thoughts appreciated.

SPARKPLUG1977 · October 01, 2004, 06:00:41 PM

Check your float height.

ponchopirate · October 01, 2004, 06:03:59 PM

Did you change your float heights? If you did you may have set them so that too much fuel is getting in the float bowls which would pour out the overflows.

ponchopirate · October 01, 2004, 06:04:35 PM

Damn, thwarted.

Kerry · October 01, 2004, 08:11:00 PM

If you need some help getting started, see my Float Height Check page. If you find that the float height is off (and you don't have a manual) we can dig up some old threads or other info to help you through setting the float height.

Ah, here's one: Crap... more help needed:float adjustment. (Excuse the title - mercdude3 was frustrated!

You can find more of the threads that I'm most familiar with on this topic by doing a Search (link at top of this page) for float height Haynes with the "Search for all terms" option checked.

treybrad · October 01, 2004, 10:14:57 PM

I just wanted to say thanks. Finally got my parts today, was putting everything together and the gas wasn't flowing on ON or RES only on PRI, and then it's crazy.. idles at like 7k, is that right? Anyway, sure enough my vacuum hose had fallen off just like octane said. Thanks! Slipped it on and she's been purring like a kitten! At least so far...

trey

callmelenny · October 02, 2004, 05:45:10 PM

Thanks again for your input. I had tried the float height trick already. I took the carbs apart again and I think one float was hanging up.

The fuel system in this thing was a real mess. I think all my problems were due varnish and particulates. I guess the good thing is I can tear things apart and put 'em back together pretty quick now.

I just got back from a 10 mile spin and had no problems. I think I am ready to hit the road.

Muchas gracias everyone, especially Kerry

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fuel starvation?