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Discussion Starter #1
So you know, its an '04 600rr but its in a quad, not a bike anymore. Its been in there ~2 years and Ive had a few fuel issues, but this one is new.

At first the engine would hesitate nonstop at about 8000, came to find out I had the fuel line tied too tight to the frame.

Since then the engine has run flawlessly.

Now it still runs perfect until about 12-13000 rpm, then its done, it will not go past that unless I force it to (hold the throttle in first gear.)

The fuel line is fine, no restrictions. This doesnt sound like an ignition problem to me, it runs absolutely normal until that point, idles fine, good power.

Heres my question now, first your opinions on the problem.

Second, how can I test the fuel pressure. I have an autometer electric fuel pressure gauge left over from parting out my car and would love to hook it up permanently, but cant think of a way to tie it in.
 

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What kind of fittings are on it? You could go to a local hose shop that sells fuel fittings, and buy something that connects into the fuel line somewhere on the high pressure side.
 

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this sounds similar to what i'm going through right now. my bike will act like it's low on gas and lose power when I hit 10K-11K. I think I may have a pinched line somewhere, not sure just yet.
 

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What if you have some knocking being picked up by the knock sensor and you are retarding the timing?
 

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Discussion Starter #5
Timing issues are definitely a possiblility. I want to rule out fuel issues first, since they were my first guess. There are a myriad of possibilities, the only downside to fuel injection. Im getting a tee spliced into my fuel line monday to hook up an autometer elec. press. gauge permanently, then ill take it out and see if it dips.


After that who knows, all my injectors, coils, and sensors have correct resistance, so I think ill be looking at either valvesprings or computer issues.
 

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Discussion Starter #7
I tested the flow, only had ~4oz/10seconds, manual says at least 6.4oz. Dissasembled, cleaned the dirty ass filter screen, reassembled, still low flow, but with the gauge its pumping 50psi perfect, unless Im way up in the RPMs and load it drops to around 35-40, but the manual doesnt specify what the pressure should be that high in the rpms. The problem I was having did seem to go away though, but now there is a slight hesitation at 8-9000 where it feels like it stutters then if I pull the throttle a little more it keeps going no problem.
 

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Replace the pump. The SM says, and I should have been more clear, 50psi at 1,300rpm (idle). If it's dropping below 50psi then you need a new pump or bypass valve. These pump kits come with a fuel strainer on the outside and a fuel filter on the inside. I don't know of a way to replace the fuel filter. Only the entire unit. The higher rpm stumbles are typical of fuel starvation.
 

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Discussion Starter #9
exactly, it only specifies pressure at idle, not high rpms under load, that's because they're tester does not allow the bike to be ridden like mine does.

I'm not disagreeing that the pump is not bad though, it may be, so ill replace it anyway.

You can replace the strainer if you disassemble the pump unit, I don't know of another filter in the system though. I may actually think about installing one to be safe.
 

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I'd be careful about installing an additional filter as you may drop the psi to the pump. Check out Chapter 2.
 

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Discussion Starter #11
I see, I didnt realize there was another filter in that unit besides the strainer, I got a little skeptical that the only filtration device was that little plastic strainer. Thats probably where my flow problems are coming from is that other filter. Seems like a stupid design to me, or a way for honda to make more $$. Car fuel filters are a good thing to change every 20k and honda didnt give us a way to change a filter without buying a new pump? After I put the new pump in Im going to tear into the old one a see if that filter can be removed permanently in place of an aftermarket one inline with the fuel hose.
 

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Discussion Starter #12
Slightly delayed....

Got the problem fixed with a new fuel pump I bought off ebay that was supposedly used, for $15 shipped, recieved it and it looked brand spanking new to me.

Out of curiosity I cut apart the old pumps filter, the thing was completely caked in a rustlike substance, which doesnt make much sense since the stock tank is plastic and my tank is aluminum?!?

I also got the fuel pressure gauge hooked up, and if anyone is curious, the RR fuel system does maintain a constant 55psi throughout the RPM range.

 

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Glad you got it fixed. The "rust" is probably from the gas station tank you were buying your gas from. Might want to find another one.
 
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