[SkyShadex]

Was reading around on the forum trying to find a solution to my problem

Symptoms:
8-10k "Rev limit". The longer I'd ride the lower it would get. Wouldn't happen at first but I'd notice it maybe 10minutes into a ride. But only really in higher gears.

Thoughts:
Post I found suggested it points to an AFR issue, bike is getting so lean at speed, paired with ram air, that it can't keep up. Fuel pump, filter, injectors or line.

Tracing my steps... Could be a kinked fuel line. So I replaced the fuel line with some leftover 6an I had from my car.

Better? But not sorted. I believe the 1/4" ID is too big and costing me fuel pressure. I'll revisit that.

I've yet to pull the fuel assembly because I'm lazy. But it could very well be the pump or a filthy filter.

My question is, I have a aeromotive 325 laying around that I'm not using. I know the gen 3 housing shorter than gen 2, I've heard the pump is smaller as well. What are the dimensions of the stock pump? Can I fit the 325?

Otherwise, I'll go my route of creating a custom hanger for it. Because upcycling is cheaper than getting a new pump.

 

[SkyShadex]

I'm taking an educated guess based on what I've learned from building my car, and what I've read about this issue on the forums.

I suppose I can plug in a gauge and check. If I could weld I'd toss in this O2 sensor I have laying around.


Forgot to update: most motorcycle fuel pumps are the 35mm variety so a 65mm is unlikely to fit without heavy modifications. Gonna give it a look over this week, clean the fuel filter at least. I got the bike at 24k so I can imagine it's pretty dirty.

 

[SkyShadex]

Or it could be the secondary injectors are shot

Also possible. I could rule this all out if I had a fuel pressure gauge on hand. Deductive reasoning my way through this.

I checked the specs on the ID's of the fuel line.

• OEM Fuel Line: starts 8mm and tapers down to 6mm on the hose.
• My Fuel Line: 1/4" ID fuel line comes in at 6.35mm.
• 6% increase in cross sectional area would also mean ~6% less volume, for the same psi.

Not that I've seen a stock map, but if the OEM map is already pretty lean up top I can see how 6% leaner might be a problem, especially with ram air. Either way, not doing myself any favors there.

Gonna spend tomorrow inspecting, and cleaning the filter, maybe crush that fuel regulator. It's just the money I'd spend on a fuel pressure gauge is close to what I'd spend on the pump anyway lol.