fuel feed issue

Roadking · 03-19-2019, 08:25 AM

Hey guys/gals I haven't been on here lately but I'm having an issue with my wifes 99 Gz250.
Bike sat in garage nearly a year. After charging battery and adding fresh gas to 1/2 tank, Took for a test ride. It was a little rough running until I got to local fuel station and topped off with 93 octane.
She smoothed out so I went on a 55mph back road and opened her up.
after reaching 60, for about 30 seconds she sputtered and died. I switched to PRI on petcock and before I slowed to 40 it started back up. So I slowly accelerated back to 60. Made it 2 miles and she quit again. Pulled over and shut off waited 2 mins, started right back. Made it back to the house after this repeated itself 2 more times. I figured its starving itself of fuel. I pulled the bowl off the carb and blew air (from my lungs) through the inlet hose and checked that the float wasnt shutting off too early. looked clean too. I sprayed some gumout cleaner all up inside the carb and float bowl and reinstalled. The petcock acts normal. No fuel flow the on or res but pri flows freely.
Took out for another test run and it took it longer but same symtoms. She idles great. Choke is working normal.
Any ideas whats causing the fuel starvation? Maybe high speed jet has some clogging?
Thanks in advance
RK

5th_bike · 03-20-2019, 10:04 AM

Likely, the little hose that brings the vacuum from the carburetor to the petcock, has aged and cracked a bit (or gone loose), and is now leaking air with as result that the fuel valve in the petcock doesn't open and your carburetor doesn't get (enough) fuel.

Vegas Street Rider · 03-20-2019, 11:08 AM

If that doesn't fix it, check the diaphragm in the petcock.

Roadking · 03-21-2019, 07:24 AM

RESOLVED!!

I noticed the gas cap had a lot of vacuum when I opened it up. I replaced it with a new one last year when I changed out the ignition switch. It came as a kit along with a new seat lock. So as to have one key for all. I rumaged around until I found where I hid the old parts and installed the old cap.
Went for a ride for 10 miles of 55+ mph. No problems!

I installed a rebuild kit in the petcock last year as well. But that dont always mean there wont be a tiny hole in it or something. I did look at the vacuum hose that goes to the carb. looked okay.

Anyway, SuzieQ seems to be happy once again and more importantly so is the wife!

5th_bike · 03-29-2019, 09:43 PM

Great, happy riding !

winglem · 04-26-2019, 10:49 PM

Your title was right on! Fuel Feed Issue

Nice work!

Roadking · 03-22-2021, 08:51 AM

well I'm back and so is this same problem! Both of the 99 250's we now have sit for nearly a year, then I revive them for another tour of Sun n Fun escorting airplanes to parking areas. Knowing these bikes are going to be sitting I add stabil to the fuel system. Park them out of the way and remove the seats and side covers to attach trickle chargers to the batteries.
I have been starting them up and letting them warm up last few weeks. Chargers off. They have been behaving and just a tad bit rough at first but smoothed out after a min or two of running. warmed up with choke off she idles great.
I have not added fresh fuel yet
.
SuzyQ died on my Queen once on short trip to friends house 10 miles away. After visiting for about an hour SuzyQ was backtalking my Queen and didnt want to stay running. We swapped bikes and I was able to get her started and manipulated the choke to keep her going. Rode her out to a road that is 55 mph and she quit on me. I had switched the choke off once I was above 40 mph and she was running fine. It was as if someone reached over and turned off the ignition switch. After stopping and waiting about 30 seconds she started right back up but not without full choke.

I think its fuel flow again and at top speeds she is using all the fuel in the bowl and shutting down. I switched the petcock to reserve but it died again as I approached our driveway.

Thoughts Gents?

Roadking · 04-02-2021, 07:50 AM

Ok,
I discovered the rectifier not doing its job fully. Only holding battery voltage during idle and momentarily increasing to 13.6v during rev increase, dropping back to 12.4v even with rpm's about 2k.

I replaced it and now she holds 13.8v at idle and 14.1 at 2k rpm. Checked at the battery with a fluke meter.

Hopefully this is what she was telling me all along. These small bikes are touchy about having the electrical system working correctly or it can give you fits!

I havent had a chance to ride her tho. My truck I use to tow them from Ga to Fla, fuel pump quit. Its a 02 GMC and its easier to remove the bed than drop the tank! Its supposed to have 50-60 psi on the rail and it putting out 12.5. Sooo after I replace that then back to SuzyQ's flow problem. Part of me wants to order another petcock rebuild kit to get a new diaphram.

Thots gentlemen?

EddieSC · 04-03-2021, 01:13 AM

I say cover your bases and get a new diaphragm if ya have the chance to have it apart.

Then again, I'm also the type that bought a brand new carb upon hearing that two different folks tried to rebuild the one currently on my GZ, so take my advice with that particular grain of salt.

03-19-2019, 08:25 AM	#1
Roadking Member Join Date: Apr 2017 Location: South of Atlanta Posts: 50	fuel feed issue Hey guys/gals I haven't been on here lately but I'm having an issue with my wifes 99 Gz250. Bike sat in garage nearly a year. After charging battery and adding fresh gas to 1/2 tank, Took for a test ride. It was a little rough running until I got to local fuel station and topped off with 93 octane. She smoothed out so I went on a 55mph back road and opened her up. after reaching 60, for about 30 seconds she sputtered and died. I switched to PRI on petcock and before I slowed to 40 it started back up. So I slowly accelerated back to 60. Made it 2 miles and she quit again. Pulled over and shut off waited 2 mins, started right back. Made it back to the house after this repeated itself 2 more times. I figured its starving itself of fuel. I pulled the bowl off the carb and blew air (from my lungs) through the inlet hose and checked that the float wasnt shutting off too early. looked clean too. I sprayed some gumout cleaner all up inside the carb and float bowl and reinstalled. The petcock acts normal. No fuel flow the on or res but pri flows freely. Took out for another test run and it took it longer but same symtoms. She idles great. Choke is working normal. Any ideas whats causing the fuel starvation? Maybe high speed jet has some clogging? Thanks in advance RK Login or Register to Remove Ads
	0

03-20-2019, 10:04 AM	#2
5th_bike Senior Member Join Date: Oct 2007 Location: HoCo, Maryland Posts: 1,349	Likely, the little hose that brings the vacuum from the carburetor to the petcock, has aged and cracked a bit (or gone loose), and is now leaking air with as result that the fuel valve in the petcock doesn't open and your carburetor doesn't get (enough) fuel. __________________ 2005 "Saturn Black", stock + tach
	0

03-20-2019, 11:08 AM	#3
Vegas Street Rider Senior Member Join Date: May 2015 Location: Henderson, NV Posts: 1,108	If that doesn't fix it, check the diaphragm in the petcock. Login or Register to Remove Ads
	0

03-29-2019, 09:43 PM	#5
5th_bike Senior Member Join Date: Oct 2007 Location: HoCo, Maryland Posts: 1,349	Great, happy riding ! __________________ 2005 "Saturn Black", stock + tach Login or Register to Remove Ads
	0

03-22-2021, 08:51 AM	#7
Roadking Member Join Date: Apr 2017 Location: South of Atlanta Posts: 50	well I'm back and so is this same problem! Both of the 99 250's we now have sit for nearly a year, then I revive them for another tour of Sun n Fun escorting airplanes to parking areas. Knowing these bikes are going to be sitting I add stabil to the fuel system. Park them out of the way and remove the seats and side covers to attach trickle chargers to the batteries. I have been starting them up and letting them warm up last few weeks. Chargers off. They have been behaving and just a tad bit rough at first but smoothed out after a min or two of running. warmed up with choke off she idles great. I have not added fresh fuel yet . SuzyQ died on my Queen once on short trip to friends house 10 miles away. After visiting for about an hour SuzyQ was backtalking my Queen and didnt want to stay running. We swapped bikes and I was able to get her started and manipulated the choke to keep her going. Rode her out to a road that is 55 mph and she quit on me. I had switched the choke off once I was above 40 mph and she was running fine. It was as if someone reached over and turned off the ignition switch. After stopping and waiting about 30 seconds she started right back up but not without full choke. I think its fuel flow again and at top speeds she is using all the fuel in the bowl and shutting down. I switched the petcock to reserve but it died again as I approached our driveway. Thoughts Gents? __________________ 1999 GZ 250 SuzyQ 1999 GZ 250 Rosey 2002 Electraglide 2003 Heritage 100 Anniv
	0

03-21-2019, 07:24 AM	#4
Roadking Member Join Date: Apr 2017 Location: South of Atlanta Posts: 50	RESOLVED!! I noticed the gas cap had a lot of vacuum when I opened it up. I replaced it with a new one last year when I changed out the ignition switch. It came as a kit along with a new seat lock. So as to have one key for all. I rumaged around until I found where I hid the old parts and installed the old cap. Went for a ride for 10 miles of 55+ mph. No problems! I installed a rebuild kit in the petcock last year as well. But that dont always mean there wont be a tiny hole in it or something. I did look at the vacuum hose that goes to the carb. looked okay. Anyway, SuzieQ seems to be happy once again and more importantly so is the wife!
	0

04-26-2019, 10:49 PM	#6
winglem Junior Member Join Date: Apr 2019 Posts: 7	Your title was right on! Fuel Feed Issue Nice work!
	0

04-02-2021, 07:50 AM	#8
Roadking Member Join Date: Apr 2017 Location: South of Atlanta Posts: 50	Ok, I discovered the rectifier not doing its job fully. Only holding battery voltage during idle and momentarily increasing to 13.6v during rev increase, dropping back to 12.4v even with rpm's about 2k. I replaced it and now she holds 13.8v at idle and 14.1 at 2k rpm. Checked at the battery with a fluke meter. Hopefully this is what she was telling me all along. These small bikes are touchy about having the electrical system working correctly or it can give you fits! I havent had a chance to ride her tho. My truck I use to tow them from Ga to Fla, fuel pump quit. Its a 02 GMC and its easier to remove the bed than drop the tank! Its supposed to have 50-60 psi on the rail and it putting out 12.5. Sooo after I replace that then back to SuzyQ's flow problem. Part of me wants to order another petcock rebuild kit to get a new diaphram. Thots gentlemen? __________________ 1999 GZ 250 SuzyQ 1999 GZ 250 Rosey 2002 Electraglide 2003 Heritage 100 Anniv
	0

04-03-2021, 01:13 AM	#9
EddieSC Member Join Date: May 2010 Location: Birmingham, AL Posts: 37	I say cover your bases and get a new diaphragm if ya have the chance to have it apart. Then again, I'm also the type that bought a brand new carb upon hearing that two different folks tried to rebuild the one currently on my GZ, so take my advice with that particular grain of salt.
	0

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