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Discussion Starter #1
2003 r6 45,000 miles

So I just scooped up this 03 r6. Runs great except that it seems to fall flat on its face at 11k. Its the same for every gear. The fuel pump is pretty load when I turn the key. Is there a way to test fuel pump pressure. I am a mechanic for cars but not much experience on bikes. I'm willing to try other things as well.
 

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Hey thanks for that. Too bad it's not just a hook up that I could test like a car. I guess that I may try a new fuel pump. I can't think of anything else. It sorta stumbles at the lower rpms sometimes. It just screams pump at me if it were a car. Well thanks I'll post back if that fixes it.
 

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Hey, is there a fuel pressure regulator. I have the tank off the bike and saw the pressure line to the rail. What about the other line coming back up that was clamped? I can't see the fuel rail but if there is one and I have a good pump I'll test that as well. May take the air cleaner to see if I can see it. Also is the any reference to how the TPS (throttle position) operates? I'd like to cover my bases. Thanks again.
 

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Hey, is there a fuel pressure regulator. I have the tank off the bike and saw the pressure line to the rail. What about the other line coming back up that was clamped? I can't see the fuel rail but if there is one and I have a good pump I'll test that as well. May take the air cleaner to see if I can see it. Also is the any reference to how the TPS (throttle position) operates? I'd like to cover my bases. Thanks again.
the fuel rail is there. it's what the pressure regulator is mounted to. the line with a normal clamp is the return line. all of the newer R6 have a returnless system where the pressure is regulated in the fuel pump instead. but the 2nd gen had a return line.
everything you need to know is in the service manual. https://www.r6messagenet.com/forums/r6-maintenance-technical/39254-r6-service-maintenance-repair-manual.html
 

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Ok hey thanks for that link has tons of useful info. My problem now is that i have a body that doesn't appear to let pressure return to the bike. On the pump assembly housing the return port isn't able to be blown through. I assume that like in a car that that port should be free flowing?
 

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Please for the love of god, if you figure this out let it be known. I've only found about 2 other threads on this issue and none of them have given me an answer. I have an 05 and last season it was running just fine, I took it out of winter storage and immediately the bike won't go over about 12k RPM's...getting super frustrating. I'm pretty certain it has to be fuel related, like you guys are already mentioning.
 

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Please for the love of god, if you figure this out let it be known. I've only found about 2 other threads on this issue and none of them have given me an answer. I have an 05 and last season it was running just fine, I took it out of winter storage and immediately the bike won't go over about 12k RPM's...getting super frustrating. I'm pretty certain it has to be fuel related, like you guys are already mentioning.
why dont you take it to a shop and let them pressure test it? should cost less than $100.
 

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That's not a bad idea. The issue I've experienced as a mechanic is a pump putting out enough pressure but not enough volume. The only true test is fuel pressure at wide open with a load and near to max rpm. I've ran a pressure tester though a hood and held it while driving and watched loss in pressure going down the road. That is what I believe I'm experiencing.

For you are you losing power at random spots and high rpm? Or is it just high rpm? Take the bike and at low rpm open up the throttle make sure the engine has to work (like a higher gear). If you get a power loss there you may be getting bad spark. If its just at rpm more that likely it's a fueling issue.
 

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@yamahacrazy I'll bring it to a shop if I can't figure it out soon. I've only had it out for a couple days as Minnesota just had an april snowstorm.
@ndnjames13 mine cuts out at the same spot on the tach every time, whether its sitting still in neutral, 1-6. Doesn't go above 12K for me. I put new NGK plugs in and coilspec coils no more than 1,000 miles ago. I actually did that to prevent a common problem that apparently only happened on the 03. So I did it for no reason but I definitely have spark.
 

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That's really wierd almost like the ecu loses the rpm signal maybe. Try down shifting to cause high revs and see if you have a tach readout above 12k
 

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That's not a bad idea. The issue I've experienced as a mechanic is a pump putting out enough pressure but not enough volume. The only true test is fuel pressure at wide open with a load and near to max rpm. I've ran a pressure tester though a hood and held it while driving and watched loss in pressure going down the road. That is what I believe I'm experiencing.

For you are you losing power at random spots and high rpm? Or is it just high rpm? Take the bike and at low rpm open up the throttle make sure the engine has to work (like a higher gear). If you get a power loss there you may be getting bad spark. If its just at rpm more that likely it's a fueling issue.
Hmm that's a good idea, I bet it will work but I can't imagine that it will solve anything. I'm curious though, will update when I try tomorrow.
 

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Hmm that's a good idea, I bet it will work but I can't imagine that it will solve anything. I'm curious though, will update when I try tomorrow.
Tried this...Bike jumped to about 12.5k and wouldn't give any more. TPS are within spec on diag mode.
 

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Update time, got the new pump in and it feels more stable at the lower rpms. Still cuts at 12K almost perfectly every gear. I'm going to completely block off the fuel return line. Ive seen that diagnose a regulator issue.
 

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So I finally removed the Yamaha fuel line. When I did I replaced it with something that I can test fuel pressure while riding. So what I found out is that I have 70 psi no matter what! Now I'm planning on running the return line directly into the fuel tank If that doesn't fix it then I narrowed it down to the regulator if that does though then the fuel pump housing is not letting pressure back into the tank. Will update again.
 

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Update time:

I apologize in advance for the horrible wind noise, I just set up this helmet cam and need to put the mic somewhere else with a cat filter, but hopefully this will give ya'll a better idea of what's going on.

https://youtu.be/Zy7eZqw1Xfc

There is a video of what's happening to me.

https://www.r6messagenet.com/forums/r6-warranty-premature-failure/1513-engine-shuts-off-while-riding.html

https://www.r6-forum.com/forums/57-garage-mechanical-help/10179-03-r6-engine-cutting-out.html

Here are a couple more threads about the issue. I forgot to mention that my bike also completely cuts out when I pull the clutch in.

I might just have two separate issues. If that's the case, this is getting seriously frustrating.

Since my last post:

-Tried 2 different ECU's from friends bikes (2nd gen R6...an 04 and another 05)
-Made sure charging system is all good (replaced battery and rectifier 1000 miles ago and stator is kicking 14v @ 5k rpms).

The threads above seemed to have died and I'd really like to figure out what the heck is going on. I think I stated this before but I also have brand new coils and spark plugs. I still suspect something fuel related.
 

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I figured this thing out finally! I put a regulator in it today. I was still getting crazy high pressures! I lifted the tank while running and the bike sounded different. I look at the fuel pressure and it was just about 44 PSI! I set the tank down and boom 90 PSI. Lifted it again and ran perfect with the correct fuel pressure. The return line was kinking and causing the pressure to constantly be high! shortened the line and no kinks. rode it and pulled to 16k like a champ!

So here is my recap
1. fuel pump replaced (loud fuel pump from sitting for a while.)
2. Built a fuel line out of fuel line from a parts store so that I could put a T fitting and read fuel pressure without the stupid Yamaha test kit.
3. Crazy high pressures NO MATTER HOW I RODE.
4. Replace regulator

**5. THE FIX I had a kinked return line causing insane pressures on the rail (Didn't notice till I had a gauge and was lifting and lowering tank while pressures went up and down)**
 

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I figured this thing out finally! I put a regulator in it today. I was still getting crazy high pressures! I lifted the tank while running and the bike sounded different. I look at the fuel pressure and it was just about 44 PSI! I set the tank down and boom 90 PSI. Lifted it again and ran perfect with the correct fuel pressure. The return line was kinking and causing the pressure to constantly be high! shortened the line and no kinks. rode it and pulled to 16k like a champ!

So here is my recap
1. fuel pump replaced (loud fuel pump from sitting for a while.)
2. Built a fuel line out of fuel line from a parts store so that I could put a T fitting and read fuel pressure without the stupid Yamaha test kit.
3. Crazy high pressures NO MATTER HOW I RODE.
4. Replace regulator

**5. THE FIX I had a kinked return line causing insane pressures on the rail (Didn't notice till I had a gauge and was lifting and lowering tank while pressures went up and down)**
Good to hear some results. I got mine on the Dyno yesterday and the dude has been tuning bikes for 30 years and he said all I need is a power commander and for him to tune it. I'll definitely check those fuel lines. I also have a couple buddies that I can swap tanks with to see if the fuel pump is causing problems. It might be a while as I need to fix my car and truck before my bike but I'll update again when I have mine fixed, hopefully it will help somebody in the future. Thanks for all your input @ndnjames13
 

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I figured this thing out finally! I put a regulator in it today. I was still getting crazy high pressures! I lifted the tank while running and the bike sounded different. I look at the fuel pressure and it was just about 44 PSI! I set the tank down and boom 90 PSI. Lifted it again and ran perfect with the correct fuel pressure. The return line was kinking and causing the pressure to constantly be high! shortened the line and no kinks. rode it and pulled to 16k like a champ!

So here is my recap
1. fuel pump replaced (loud fuel pump from sitting for a while.)
2. Built a fuel line out of fuel line from a parts store so that I could put a T fitting and read fuel pressure without the stupid Yamaha test kit.
3. Crazy high pressures NO MATTER HOW I RODE.
4. Replace regulator

**5. THE FIX I had a kinked return line causing insane pressures on the rail (Didn't notice till I had a gauge and was lifting and lowering tank while pressures went up and down)**
often it's the stupid simple shit we overlook that bites us in the ass. yamaha actually had a service bulletin a long time ago (could have been a recall I just can't remember) for the 2003 about kinked fuel lines.
 
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