FinalImpact

2 Da Street, Knobs R Gone
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Not to lead the witness but there are 3 fuel pumps on fleabay from $75 to $175 make offer...
 

L3FTY

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Excellent, i'll fall back to that after i do some experimentation on this one. I'm going to try soaking, over-pressuring, ultrasonic, and whatever the term for throw it against concrete a couple of times is. if it comes down to it, uncrimping it and opening it up. What have i got to lose? My hope/suspiscion is that part of the diaphragm is "glued" to the seat and/or body in the regulator. I've been working to find cross-compatibility for this part. It looks like certain toyotas use this FPR but with different pressure values. I may even call Denso and see if they know anything about a 250kPa unit. The ones in the Toyotas sell for as cheap as $7 new so if i can find a source i think it would be really helpful for the community.
 

FinalImpact

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If you dig in, Denso has like 150 variants of this pump housing that rolls out to a whole lot of Yamaha's, Honda's, and other bikes. Do an ebay search for denso pumps.

As you see tho it is the manufacturer who picks the pressure and it comes down to looking up the specs for each one. That said if you could do a *Where Used* on the PR by itself, that would be the ticket!

I have good gauges here but have never had a need to check mine.

FWLIW - I would be reluctant to pull my tank and swap it for just anyone so good luck with that!
 

L3FTY

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The plot remains thick. Pulled the FPR last night and isolated the test to it. It opens at...36 psi :eek:

Hdi7Rs0.jpg

I blasted some solvent through it, and hooked a pick into the spring from the back side and pulled it around. I could move the diaphragm around a bit but i cant confirm that i completely opened it at any point. I put everything back together and T'd the pressure gauge back into the fuel line. The bike idles at 39-40 psi with little fluctuation when free-revving. I guess under pure hydraulic pressure the FPR is still not fully opening.

I went out and filled the tank last night. Got a nice puff of unburned fuel this morning on startup, but i rode the bike to work anyway. The bike floated the front wheel in 1st gear, which my butt dyno tells me is around 90 horsepower so we're not down on power. I'm going to run this tank through it and retest everything.

I'll do a dumpster dive through FSMs and see if i can find cross-compatibility on a 250kPa FPR. Based on a cursory pass, it seems like the majority of units using in-tank pumps operate at 42 psi. Looks like the FZ6 and FZ6R are the minority when it comes to rail pressure spec.
 
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