Bike: 2001 Concours ZG1000A16, 60,000 Miles

Problem: Fuel Tank (petcock?): Bike stalls when switching from On to Prime and/or Reserve

*** 5 Questions below article ***

The problem of the bike stalling when switching the petcock from On to Prime and/or Reserve started about 3K miles - 1 1/2 months ago immediately after the bike was serviced at the dealer. The bike was serviced for a a starter issue and the dealer replaced the starter solenoid. I don't know if the dealer removed the fuel tank to replace the the solenoid (I doubt it). Within a couple of hundred feet from the dealer the bike began to sputter so i switched to prime but it continued to sputter so i switched it to reserve. The sputtering continued for a few more seconds and i continued to switch between prime and reserve until the bike stalled. The bike pretty much started right up when put on reserve after stall. Took the bike back to the dealer and he said it was most likely air in the lines and will work it's way out.

For the next 3K miles (1 1/2 mths) there were constant similar sputtering problems but it wasn't as noticeable and without the bike stalling until last week when it died at night on a very, very busy NY parkway. At this point this issue has become a danger. During this stall the bike sputtered real heavy for about 1/4 mile, say thirty seconds, before the bike turned off. However, this time the bike wouldn't start immediately like it always had in the past. I opened the fuel tank filler cap to help vent the system and it still didn't start. I continued to try to start bike and then I got nervous that I was going to kill the battery. I waited for no more than two minutes and the bike started with petcock in reserve.

Road the next 22 miles on reserve and then filled up 6.2 gallons. Coincidently the bike needed to be switch over to reserve at 200 miles and it's been that way since the stalling initially started. Before this issue the bike would always get at least 225-250 miles before the need for reserve. Another thing, since this recent stall the bike would, at times, not immediately start and one time it was warm and would not start with or without choke open. This was only for a few seconds but I figured I mention it. In the 60,000 miles of owning and riding this bike it always immediately started. The problem has not occurred again because I have not ridden enough to switch to reserve. Tomorrow the bike should be at the need for reserve.

THE FIX:
The most obvious fix would be is to replace the petcock. Replaced petcock with genuine Kawasaki petcock three years ago at about 57K miles and find it strange it would fail again in only 3K miles and the original petcock lasted 57,000 miles. Something to note is that the bikes was ridden much over the past three years, only about 3000 miles. Also, the fuel filter has also been recently changed.

Questions:
1. Would it be the petcock or possibly some other issue?
2. Is the petcock worth rebuilding or replace with new?
3. Why is the bike only getting 200 miles before reserve instead of the normal 225-250 miles?
4. What's causing the hesitant starting issue that recently started (in fact, it only been this tankfull that the hesitation has been occurring).
5. Why have I never put more than 6.5 gallons into the tank - this is even after the bike has run out of gas. It's supposed to have a 7.5 gallon tank but i have never came close to that.

Thx for being patient reading all this & I look forward to your suggestions.

~ David

UPDATE

The bike finally needed to switch to reserve this past Sunday night. It went from sputter to reserve with just a little hesitation but not as smoothly as when I had no problems. I did not switch to prime first; went directly to reserve. The call for reserve again happened at the 200 mile marker. This really baffles me because, like I said in the original post, the bike has always switched to reserve at appx 225 - 250 miles. The reduced mileage did't happen until the back came back from service at 57K. Again, the bike is at 60K miles (and is 13 yrs old old).

As someone posted, the dealer may have removed the tank during its last service and upon reinstalling the tank may have pinched a vacuum or fuel line. I was just about to purchase a new petcock but I am now going to hold off until I have another chance to evaluate the condition of the fuel & vacuum lines. I had the tank off last week inspecting wiring on another issue (if you like see Directional lights go on after bike is switched off - problem not yet resolved). I replaced fuel filter and didn't notice any problems with lines (fuel tank issue has been happening way before filter was replaced).

I will now proceed to remove tank again but this time a will make a much closer examination of the lines and anything else that may be the culprit. I was about 15 miles from the gas station by my home when switched to reserve and had no problem from the initial switchover sputter. The problem I now have is that I filled the gas tank to full (I knew I shouldn't have done that) and only have ridden it appx 2 miles. I told myself last time not to remove tank again unless it's pretty much empty. Too much gas makes it too heavy and I dont want to risk scratching the tank during reinstall. So I need to ride the tank down. I'm not going to ride to this weekend and hopefully I'll get to inspect the fuel/vacuum lines

Thx all for your technical support. I hope to get to look at the problem during the next week so around then I hopefully will post another update.

hope you all had safe Columbus Day weekend riding

~ David

Do you have overflow tubes installed in the carb bowls?

Take the petcock apart to make sure the dealship didn't reassemble something wrong or damage the rubber parts.  They are completely rebuildable, Murph has an excellent kit.  Old parts out - new parts in.

60k miles and only 3k last year.  Have you ever serviced the carbs?  That might be where your gas mileage went, the fuel level in the bowl creeps it's way up after a long period of time due to weakening springs, seat wear, and/or the float bending or warping also.  This may also be where your hard starts are coming from.  You may want to drain the bowls a few times to see if some water might have got into the carbs from moving the tank around.

I'm sure you have read on here that fuel filters have been known to cause problems when they are not installed exactly right or the correct one.  Whatever you have, it needs to be 5/16" inlet and outlet.  I would remove it from the equasion until you resolve it.  As for your petcock, make sure you are lining it up exactly on the marks so you aren't restricting gas flow.  I've misaligned before and it will starve and sputter.

I remember reading a while back that you can never get to the last 1/2 gallon of fuel.  To get to some of the last gallon of fuel you also might need to tilt the bike to the left so it can get over to the petcock.

Remove tank COMPLETELY drain. Now fill with NEW fresh gas.
My bet is you have water in the tank.

I agree about ditching that fuel and geeting the tank clean and free of any water that collects down in the bottom...

You can drain the tank down prior by using a 5 gallon gas can, and pull the fuel line off the petcock, slip a 2foot section of hose on, and drain it down using the PRIME position to lighten the tank. This will also allow you to inspect petcock function, and switch repeatedly to flush it out also at the same time. Then remove it , tilt it sidewayss and complete the draining. When that's done, use a turkey baster with a hose attached, to reach those lower wings, to suck out everything there, followed by a wire coathanger with rags attached, to sop any remaining water laden fuel from thos nether regions, swabbing them well, you'll get a visible amount of fine rust cleaned out that way. Flush the tank a bit with a small amount of clean fuel, and dump that totally. Reinstall, and add about 2 gallons of FRESH fuel, from a NEW CLEAN gascan, and add about a hlaf bottle of IsoHeet.
Ride the bike and use that fuel up, and refuel with gas from a different station, one that lives on high ground, and sells lotsa fuel...

As for your milage losses, cleaning your airfilter, and adjusting valves, will drastically improve milage... its likely time.

The dealer should not have had to remove the tank for a solenoid replacement, but everytime a tank is removed, and shook up, and replaced, there is a higher incidence of contaminate laden fuel issues immediatly following...just a fact.

Please edit your original post, to remove the duplicate post it contains, thanks in advance.

If there is an inline fuel filter, maybe it is the culprit. 

Changing out the fuel would also remove that from the equation.

Correct size and length of fuel line and routing should be checked. 

Fellow riders....I have not yet investigated the problem.  I have been on several trips since last post but have not yet returned to my garage with a low tank of gas.  Don't want rto remove tank with too much gas in it.  I'll get there.  The first thing I will check are the fuel and vacuum lines.  If needed,proceed from there.

~ FYI, David