Fuel Pump Testing

[ZX-12R]

Here is the issue: 500+ miles this past Sunday with no issues at all. Today I take the 12R out (Tuesday) and it's like I hit a brick wall around 8K RPMs. The bike is still strong under 8K but the throttle feels "sluggish" for lack of a better description.

After doing a little bit of research, it appears that 12Rs seem to have an issue with their fuel pump. I turned my ignition on and off several times and twice in a row the pump sounded odd while charging the fuel rail. After that it cleared up and I could not repeat the sound. The pump has a touch over 21K miles on it.

I have warranty coverage on the bike through July of '09 so getting it fixed isn't the issue. Getting it fixed in a reasonable amount of time is! Is there a way I can test the fuel pump so when I go to G&G for the warranty repair I can give them definitive proof that the pump is to blame to speed up the process?

I could change the pump myself in about 30 minutes but the shop must do all warranty repairs. If it were not so retardedly expensive ($400) I would just bypass the warranty and buy the pump myself.

[SSearchVT]

You can pick up a fuel pressure gauge at just about any good parts store ( I got mine from Napa - not the best quality, but I don't use it too often). Make sure it is for fuel injection and has a pressure relief button. You may have to monkey around with a few plumbing bits to get it hooked up to the fuel line of your bike, or the fuel rail (if you can get to it). The service manual or internet surfing can get you the pressures and proper testing techniques. Good luck...

[ZX-12R]

I know it isn't plugs and coils because the engine revs fine when not loaded. I know it isn't air because my filters are clean and my throttle bodies (including sub throttles) are are operating properly. That leaves fuel. I experimented a little more and found that I could get above 8K by backing off the throttle. In my head that means since the injectors will be on for a shorter period of time, the fuel pump can maintain a higher pressure and deliver closer to the correct volume of fuel to the cylinder thus giving me the power to accelerate the engine above 8K while loaded.

I managed to get access to a shop manual for it which I should have bought a while ago but that is beside the point.

When the ignition is first turned on, the pump is run for 3 seconds to charge the fuel rail. The volume of fuel discharged during that time should be 83mL (2.8 US oz) or more.

The fuel pressure with the engine off and the pump running should be between 41 and 46 PSI.

Hopefully tomorrow or Saturday I can get the time to run through it.

[ZX-12R]

Also found out that there is a fuel filter internal to the fuel pump that can be cleaned. Since my last fill-up took 4.8 gallons and I have a 5 gallon tank, it is possible some crap was pulled into the filter.

Based on the noise it made a couple of times, I doubt this is the issue but it is easy to check.

[Punjistick]

figured out what the problem is yet?

[ZX-12R]

I cleaned the fuel filter which is inside the fuel pump and that let me get the RPMs past 8K. It is still sluggish on the top end which means I probably don't have the right fuel pressure. This coming weekend I should have it pressure and flow tested.

[Punjistick]

bummer

[ZX-12R]

Well it took a while for me to get the repair done but the 12R is finally running properly again. Kawasaki covered the repair under my extended warranty. The fuel pump should maintain about 42PSI under normal conditions but mine was only putting out 26PSI. HKPowersports in Hooksett did the repair for me as they are right up the road and I was impressed with their no nonsense "we'll get this squared away as soon as possible" way they treated me.

My 5 year warranty cost $500. The fuel pump was about $420 and a few hours of labor would have been $210 so it just paid for itself since I didn't have to pay a dime!

When you've riding an SV650 for the past couple of weeks it is exhilarating to get back on a motorcycle that out powers it by over 100HP at the wheel.

[Punjistick]

Nice! Good to hear that the warrenty worked out well.