how to tell?
 

How do i tell if my fuel pressure regulator is going?
Is it a part that will slowly go bad, or eather it works or it doesn't?

On a full tank, 6th gear about 6k rpm (i ride like i own the roads) im getting about 120 miles before my reserve light comes on. I have 38k original miles on the throttle bodies. Time to replace that part, or is that just average mpg for my rpm?

It starts and revs no problem, if i hold it at one rpm it seems a little lumpy where rpms don't hold at a exact and steady number.

Is there a reduction in mileage? 120 seems ok. When the fpr goes, it will be more like 70 and be running super rich, black smoke, fouling plugs, and be barely running.

Pull the vacuum line and look for fuel. give the fpr a little vacuum, see if it holds or if it leaks fuel.

sounds about right.

The only reason i ask is because i had a stunt tank on it befor (this test was done same day same gas station, same price)

stunt tank, from top of the reserve to the lid took $8 to fill. got me 60 mile average.
stock tank, from top of the reserve to the lid took $12 to fill. Got me 125 miles.


Can someone please explain why for just $4 more, i got over dubble the mileage for riding the same route twice. Thats why i ask if my FPR is going bad or not.
ONLY veriable to change was the tank its self. I used same fuel pump in both tanks, and Same gas lid.

maybe the reserve sensor in the stunt tank was off?

Reserve sensor is on the fuelpump. which stayed the same in BOTH tanks... i used the same fuel pump in both. ONLY difference is the metal tank its self.

What was the price per gallon on each day?

Like i said, SAME DAY i did this with BOTH tanks. Price was like $3.52 i think. But i did this test, SAME DAY, SAME GAS STATION, with SAME PRICE

Whoops, Sorry, I missed those details. That is a pretty drastic mpg change. I'm as puzzled as you.

LoL, i let me friend do the same test, he got slightly better mpg, he got like 70 on stunt and like 145 on regular, but he rides more calmly than i do. but hes and i are as confused..