Need Help New Member + 2008 questions: key, wheel lockup

[grcamna7]

Sad answer from Quantum Customer Support:

View attachment 93734

I appreciate your research.

 

[Ben Franklin]

Well that sucks...

Are you going to try this pump or ?

..

Well, here are next steps, in my mind, at least:

I magnified the failed OEM regulator to get the part markings.

Says Denso 4760 9J12 on it




Searched internet, including Denso's website, and failed to find it.

Called Yamaha dealer, and they can't find it. Just buy a $450 fuel pump m

So, here is the path:

1. Have an RMA number for the Quantum 50 psi unit that is on its way here. I think i will install it and see if the closed loop system will adjust for the higher pressure. I.e. install it, see how it runs, and read a plug after a few miles.

If it isn't horribly rich, leave it in and call it good. If it is horribly rich, pull it and return it.

2. Of all the fleabay Chinese suppliers, some claim 350 kpa (50 psi) and call it a performance improvement, some dont specify pressure, and one claims 300kpa (47 psi.) I might risk $25 on the supposedly 300 kpa unit, and see how it does, if i can't find a 250kpa one somewhere.

Who'd a thought it would be this big of a pain in the ass to just buy the right regulator?

 

[Gary in NJ]

You can compensate for the extra fuel by adjusting your CO trims down. Also, looking at the photos of the bike I see it still has the OEM exhaust. If you have been thinking about an aftermarket unit, this might be good justification to make that change as the additional flow well help offset the extra fuel. On the airflow side you could install a K&N filter (higher flow...but less filtering) and open up the airbox inlet.

 

[Ben Franklin]

You can compensate for the extra fuel by adjusting your CO trims down. Also, looking at the photos of the bike I see it still has the OEM exhaust. If you have been thinking about an aftermarket unit, this might be good justification to make that change as the additional flow well help offset the extra fuel. On the airflow side you could install a K&N filter (higher flow...but less filtering) and open up the airbox inlet.

Yep, kinda thinking about an exhaust. Might be a good excuse to pull the trigger. Has a k&n filter, already, as it's only mods from stock that I have found.

We will see how it does on the 50 psi Quantum regulator. I also ordered a 300 kpa 43.5psi claimed regulator off ebay.

Should create a few data points for the future collective to consider.

 

[Ben Franklin]

So... I had a few minutes last night to screw around with putting the 50 psi fuel pressure regulator in, and going for a 30 mile or so test drive.

Pulled #4 plug out to take a look, before starting it with the new regulator in place. Plug was a little dirty from messing around with 12 to 22 psi from the failed regulator: Some soot and a little raw gas from blipping and bogging.




After at test drive that may or may not have seen triple digits out on an undisclosed freeway:

Considering that it is not a new plug, I think fueling looks to be mostly ok. Probably a bit rich, but not terrible.


same plug, more light:

First impressions on drivability.

Wow. Runs great.

Idle now adjusts. Hot start issues are gone.

Strong pull from idle on up to redline. No more bogging.

Probably need to fiddle with idle a little, yet. I noticed once or twice when I was down shifting and chopped the throttle back that it might have died. Restarted letting the clutch out, but a little unnerving.

Idled at the stop lights fine, though.

Too early to tell on fuel milage, but I was kinda ripping on it to see how it would run, so not likely high milage.

I have a 300kpa (42.5 psi) regulator coming in the next week, so may pull the 350 kpa (50 psi) regulator out and replace it, but I don't think I will worry too much. Bike has suddenly become rideable!

Thanks for all the help along the way!

 

[Gary in NJ]

You are well on your way. A throttle body sync is probably in order as well. Another thought - the FSM lists the fuel pressure at 36.3 psi (250kPa)... but is this a minium pressure. I wonder if there is a service limit above that value.