2000 Katana GSX750F Petcock question

suzukisoul · 07-05-2012, 12:28 PM

I can not get gas to flow at a steady rate. This is my first bike and am new to the motorcycle world. I was wanting to know if the vaccum line hooked up to the petcock is necessary because here is my plan: gutting the petcock so the gas will be gravity fed, plugging up the vaccum port on the carb and petcock and installing a inline shut off valve right before the in line fuel filter because I can not find a petcock on ebay and really don't want to pay $130 for a new one. Any input as to what I can do to fix the petcock or if my idea would work.

primalmu · 07-05-2012, 12:47 PM

What exactly is the problem you are having? How do you know the gas is not flowing at a steady rate? How do you know it is the petcock and not something else (like fuel line routing)?

Check the vacuum line for cracks. Check your fuel line routing. If you find it is the petcock, a $30 rebuild kit would be a better option.

suzukisoul · 07-05-2012, 01:12 PM

I have put new fuel lines in, so what do you mean by fuel line routing? i have it running parallel with the carbs then down to the base of them. And I have a clear fuel filter so I can see the flow rate, which is slow. If I let it sit for 10mins it will fire up but dies shortly after or instantly if I apply the throttle. And I know its the petcock cause I had it running last week until I took the petcock apart and fixed the small spring that pushes the plunger. I have inspected the vacuum line and found nothing wrong with it. And also I cannot find a rebuild kit for my year. Only one I was able to find was the 89-97.

Squisher · 07-05-2012, 01:29 PM

89-97 rebuild kit works for the 98+
I don't remember if there is any adapting necessary, but I know you can use it.

You can also determine if the petcock is the problem by bypassing it by rigging up an external fuel reservoir like an oil bottle, or a funnel that fits in the fuel line and try running it that way.

How long have you had the bike?
Do you know if it sat for any amount of time?
Did this start after you changed the filter? It might be the filter not allowing enough flow.
Does the behavior change when you put the petcock in the "Prime" setting?

Another thought:
My Kat will run for a bit (like a minute or so) on just the fuel in the carb bowls, so you should get that much runtime (esp. at idle) even if you have slow flow through the petcock. The fact that it dies as soon as you open the throttle indicates something other than the petcock is not quite right - not saying that you don't have a problem in it, but that there is something else you should be looking for first.

If the bike sat any amount of time before you acquired it you're due for a thorough carb cleaning - that sounds more like what's going on IMO.

primalmu · 07-05-2012, 01:38 PM

Do you still have problems if the petcock is on PRI (prime)? If so, then the petcock isn't the problem.

Did you just put the fuel filter on? If so, take the it out and see if that helps. I tried to put a filter on my bike and was unable to route the fuel line to prevent it from kinking.

suzukisoul · 07-05-2012, 01:41 PM

The 89-97 does not come with the spring that pushes the plunger. But if I bypassed it, wouldnt the vacuum line not being used have some effect. I have had the bike for about a month, it sat for about 3-4 months before I got it(but like I said, I have had it running and rode it), It started after I tried fixing the spring inside the petcock, and no, the prime setting does not effect it. This petcock confuses me to because it does not have an off setting. Its prime-on-reserve.

suzukisoul · 07-05-2012, 01:43 PM

Quote:

Originally Posted by primalmu

Do you still have problems if the petcock is on PRI (prime)? If so, then the petcock isn't the problem.

Did you just put the fuel filter on? If so, take the it out and see if that helps. I tried to put a filter on my bike and was unable to route the fuel line to prevent it from kinking.

Like I said I have had it running and rode it, it previously had a fuel filter and I replaced it, and it does not cause it to kink. Im thinking it is something to do with the flapper gaskets(if that is the correct term).

suzukisoul · 07-05-2012, 01:52 PM

Quote:

Originally Posted by Squisher

89-97 rebuild kit works for the 98+
I don't remember if there is any adapting necessary, but I know you can use it.

You can also determine if the petcock is the problem by bypassing it by rigging up an external fuel reservoir like an oil bottle, or a funnel that fits in the fuel line and try running it that way.

How long have you had the bike?
Do you know if it sat for any amount of time?
Did this start after you changed the filter? It might be the filter not allowing enough flow.
Does the behavior change when you put the petcock in the "Prime" setting?

Another thought:
My Kat will run for a bit (like a minute or so) on just the fuel in the carb bowls, so you should get that much runtime (esp. at idle) even if you have slow flow through the petcock. The fact that it dies as soon as you open the throttle indicates something other than the petcock is not quite right - not saying that you don't have a problem in it, but that there is something else you should be looking for first.

If the bike sat any amount of time before you acquired it you're due for a thorough carb cleaning - that sounds more like what's going on IMO.

On your thought, I cleaned the carbs the first day I started bringing this beast back to life. I have narrowed the problem down to the petcock, thats why I was asking input on my idea also

Squisher · 07-05-2012, 09:32 PM

Just checking, I didn't know the full history and was making sure nothing got overlooked.

The on/pri/res I think is more common on more modern machines (the 83 Ascot I had had on/off/res).

You may still want to try to rig something up temporary to try to bypass the petcock altogether, that will be the definitive answer if it is the culprit or not. You may have to get creative, I know I have a funnel that is small enough to fit the fuel hose so I can just fill that with gas.

Some gear oil bottles will have a nib end on the cap that you can fit inside a fuel line too, or buy a brass hose barb with a threaded end and thread it through a hole drilled into a 2-liter soda bottle cap.

If you do that and the problem still exists then your petcock isn't the problem, at that point I would try bypassing your new filter, and just work your way down.

Good luck!

If you were closer I'd loan you mine for a bit, but unfortunately your a long way off from Indiana

suzukisoul · 07-14-2012, 02:36 PM

Where can I find one for a 2000 gsx750f
Cause it's impossible to find it

07-05-2012, 12:28 PM	#1
suzukisoul Verified Join Date: Jul 2012 Location: Austin, Tx Posts: 19	2000 Katana GSX750F Petcock question I can not get gas to flow at a steady rate. This is my first bike and am new to the motorcycle world. I was wanting to know if the vaccum line hooked up to the petcock is necessary because here is my plan: gutting the petcock so the gas will be gravity fed, plugging up the vaccum port on the carb and petcock and installing a inline shut off valve right before the in line fuel filter because I can not find a petcock on ebay and really don't want to pay $130 for a new one. Any input as to what I can do to fix the petcock or if my idea would work.

07-05-2012, 12:47 PM	#2
primalmu 2005 Bandit 1200S Join Date: May 2008 Location: Starkville, MS Posts: 4,303	What exactly is the problem you are having? How do you know the gas is not flowing at a steady rate? How do you know it is the petcock and not something else (like fuel line routing)? Check the vacuum line for cracks. Check your fuel line routing. If you find it is the petcock, a $30 rebuild kit would be a better option. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

07-05-2012, 01:12 PM	#3
suzukisoul Verified Join Date: Jul 2012 Location: Austin, Tx Posts: 19	Petcock I have put new fuel lines in, so what do you mean by fuel line routing? i have it running parallel with the carbs then down to the base of them. And I have a clear fuel filter so I can see the flow rate, which is slow. If I let it sit for 10mins it will fire up but dies shortly after or instantly if I apply the throttle. And I know its the petcock cause I had it running last week until I took the petcock apart and fixed the small spring that pushes the plunger. I have inspected the vacuum line and found nothing wrong with it. And also I cannot find a rebuild kit for my year. Only one I was able to find was the 89-97.

07-05-2012, 01:29 PM	#4
Squisher Senior Member Join Date: Jan 2011 Location: Franklin, IN Posts: 238	89-97 rebuild kit works for the 98+ I don't remember if there is any adapting necessary, but I know you can use it. You can also determine if the petcock is the problem by bypassing it by rigging up an external fuel reservoir like an oil bottle, or a funnel that fits in the fuel line and try running it that way. How long have you had the bike? Do you know if it sat for any amount of time? Did this start after you changed the filter? It might be the filter not allowing enough flow. Does the behavior change when you put the petcock in the "Prime" setting? Another thought: My Kat will run for a bit (like a minute or so) on just the fuel in the carb bowls, so you should get that much runtime (esp. at idle) even if you have slow flow through the petcock. The fact that it dies as soon as you open the throttle indicates something other than the petcock is not quite right - not saying that you don't have a problem in it, but that there is something else you should be looking for first. If the bike sat any amount of time before you acquired it you're due for a thorough carb cleaning - that sounds more like what's going on IMO. Last edited by Squisher; 07-05-2012 at 01:35 PM.. Reason: wrong button

07-05-2012, 01:38 PM	#5
primalmu 2005 Bandit 1200S Join Date: May 2008 Location: Starkville, MS Posts: 4,303	Do you still have problems if the petcock is on PRI (prime)? If so, then the petcock isn't the problem. Did you just put the fuel filter on? If so, take the it out and see if that helps. I tried to put a filter on my bike and was unable to route the fuel line to prevent it from kinking. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

07-05-2012, 01:41 PM	#6
suzukisoul Verified Join Date: Jul 2012 Location: Austin, Tx Posts: 19	Petcock The 89-97 does not come with the spring that pushes the plunger. But if I bypassed it, wouldnt the vacuum line not being used have some effect. I have had the bike for about a month, it sat for about 3-4 months before I got it(but like I said, I have had it running and rode it), It started after I tried fixing the spring inside the petcock, and no, the prime setting does not effect it. This petcock confuses me to because it does not have an off setting. Its prime-on-reserve.

07-05-2012, 09:32 PM	#9
Squisher Senior Member Join Date: Jan 2011 Location: Franklin, IN Posts: 238	Just checking, I didn't know the full history and was making sure nothing got overlooked. The on/pri/res I think is more common on more modern machines (the 83 Ascot I had had on/off/res). You may still want to try to rig something up temporary to try to bypass the petcock altogether, that will be the definitive answer if it is the culprit or not. You may have to get creative, I know I have a funnel that is small enough to fit the fuel hose so I can just fill that with gas. Some gear oil bottles will have a nib end on the cap that you can fit inside a fuel line too, or buy a brass hose barb with a threaded end and thread it through a hole drilled into a 2-liter soda bottle cap. If you do that and the problem still exists then your petcock isn't the problem, at that point I would try bypassing your new filter, and just work your way down. Good luck! If you were closer I'd loan you mine for a bit, but unfortunately your a long way off from Indiana

07-14-2012, 02:36 PM	#10
suzukisoul Verified Join Date: Jul 2012 Location: Austin, Tx Posts: 19	Petcock rebuild kit Where can I find one for a 2000 gsx750f Cause it's impossible to find it

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