Petcock in Prime Position Only

webbmeister25d · 07-09-2012, 09:17 AM

Good morning,

Thank you for permitting me to become a member of your community. I will do my best to contribute at least as much as I receive.

We have just purchased a 2007 GZ250. It has fewer than 1000 miles on it, which indicates to me that it has spent a long time idle. The bike fires right up, and when in the ON or RESERVE position will run for a short while (whilst being ridden) and then stall while underway. It will then refuse to fire up as long as the petcock is on the ON or RESERVE position. Putting the petcock in the PRIME position causes the bike to start almost immediately. Leaving the petcock in the PRIME position whilst riding eliminates the stalling problem altogether. (I do remember to put the petcock in the ON position when parking the bike.)

The bike did receive its 600 mile service. There was very little fuel in the tank when the bike was purchased. I have filled it with fresh fuel and added 4 oz. of B-12. Since the issue is resolved by running the bike with the petcock in the PRIME position, it seems that the issue is related to fuel supply. Then again, I am new at this so ...

Would anyone care to share his or her thoughts on what might be going on here and what I might do to cause the bike to run properly in its appropriate mode?

Many Thanks,

Jim

raul10141964 · 07-09-2012, 11:43 AM

check the vacum line in the back of it

bonehead · 07-09-2012, 02:09 PM

Quote:

Originally Posted by raul10141964

check the vacum line in the back of it

:plus1:

Water Warrior 2 · 07-09-2012, 02:40 PM

My first thought too. There are 2 lines on the back of the fuelcock. 1 for fuel going to the carb and the other is for vacuum to operate the petcock in the ON and RESERVE positions. It may have just come loose or is damaged. Any auto parts store will have it if you need it.

webbmeister25d · 07-10-2012, 08:52 PM

Thank you all. I've had a moment to check on your suggestion and found that there is no vacuum line attached to the back of the petcock. I'll purchase and install one and report on the results. Thank you again for the valuable information!

Jim

webbmeister25d · 07-10-2012, 10:04 PM

YES! Success! It is now too dark to ride (still learning) but having replaced the missing line the bike runs ever more smoothly, and revving a little on the throttle does not cause backfires (as muffled as they were without the line) and stalling. I'll take her out in the morning, but I suspect this has done the trick. Thank you so much! :2tup:

Jim

07-09-2012, 09:17 AM	#1
webbmeister25d Member Join Date: Jul 2012 Location: Wauconda, IL Posts: 35	Petcock in Prime Position Only Good morning, Thank you for permitting me to become a member of your community. I will do my best to contribute at least as much as I receive. We have just purchased a 2007 GZ250. It has fewer than 1000 miles on it, which indicates to me that it has spent a long time idle. The bike fires right up, and when in the ON or RESERVE position will run for a short while (whilst being ridden) and then stall while underway. It will then refuse to fire up as long as the petcock is on the ON or RESERVE position. Putting the petcock in the PRIME position causes the bike to start almost immediately. Leaving the petcock in the PRIME position whilst riding eliminates the stalling problem altogether. (I do remember to put the petcock in the ON position when parking the bike.) The bike did receive its 600 mile service. There was very little fuel in the tank when the bike was purchased. I have filled it with fresh fuel and added 4 oz. of B-12. Since the issue is resolved by running the bike with the petcock in the PRIME position, it seems that the issue is related to fuel supply. Then again, I am new at this so ... Would anyone care to share his or her thoughts on what might be going on here and what I might do to cause the bike to run properly in its appropriate mode? Many Thanks, Jim Login or Register to Remove Ads
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07-09-2012, 11:43 AM	#2
raul10141964 Senior Member Join Date: Apr 2012 Location: Elkhart, Indiana Posts: 369	Re: Petcock in Prime Position Only check the vacum line in the back of it
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07-09-2012, 02:40 PM	#4
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	Re: Petcock in Prime Position Only My first thought too. There are 2 lines on the back of the fuelcock. 1 for fuel going to the carb and the other is for vacuum to operate the petcock in the ON and RESERVE positions. It may have just come loose or is damaged. Any auto parts store will have it if you need it.
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07-10-2012, 08:52 PM	#5
webbmeister25d Member Join Date: Jul 2012 Location: Wauconda, IL Posts: 35	Re: Petcock in Prime Position Only Thank you all. I've had a moment to check on your suggestion and found that there is no vacuum line attached to the back of the petcock. I'll purchase and install one and report on the results. Thank you again for the valuable information! Jim Login or Register to Remove Ads
	0

07-10-2012, 10:04 PM	#6
webbmeister25d Member Join Date: Jul 2012 Location: Wauconda, IL Posts: 35	Re: Petcock in Prime Position Only YES! Success! It is now too dark to ride (still learning) but having replaced the missing line the bike runs ever more smoothly, and revving a little on the throttle does not cause backfires (as muffled as they were without the line) and stalling. I'll take her out in the morning, but I suspect this has done the trick. Thank you so much! :2tup: Jim
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