Gas mileage on an 09 just went bad

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roust84

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I was doing well with MPG for the first 500 miles or so getting upper 40 mpg but now after I did an oil change I cant got more than 50 miles on half a tank. What give? I'm getting worse milage now well commuting on the 5 and 405 freeways then I did riding hard in the canyons doubled up, BY FAR!

Everything is stock on the bike...

I did remove the big ol mufflers for a bit just to mess around well all the fairings were off. Maybe this could have freaked out the computer and I'm still seeing the effects of it? I'm not sure how similar these computers are to a car computer. Perhaps a ecu rest is in order?

Help!
 
That would be like what, 20 miles to the gallon then? more or less.....something seems way way wrong. Bad gas maybe? I hope its not a real problem for you. If you took off the pipes maybe when you put them back on something got clogged up and in the way...IDK. thats wierd.???
 
Just a thought? My 08 gauge and/or sending unit was acting inconsistently for the first few tank fills. Whats wierd is that I bought it with 1600 miles on it.It then cleared up and has been fine ever since.
When you refill,how much fuel is it taking? There would be an obvious problem with the way it was running if it was using an excessive amount of fuel. Prob. just a glitch with the sending unit or electronics,which the gen 2 is known for????
The ecu is still not up to car standards,though I am not a mechanic by trade,just what I have heard.
 
If this were me, I'd probably re-ask this question in the Technical > Busa Problems section... ???
 
III said:
If this were me, I'd probably re-ask this question in the Technical > Busa Problems section... ???
Click to expand...

Sorry. This is only my second post on these forums. Not extremely familiar with the forums yet. Now that you point that out, that would seem to be a more appropriate location, but I would hate to create duplicate posts now.

BTW what is white on the end of the pipes mean?
 
I had bike stock
then Muzzy slip ons
then 4into1 Muzzy with Dyno tune and xtre
then Brocks full Alienhead , xtre , and dyno tune

Base hp numbers were 165
Last dyno run was 186 hp

I have gotten 25-30 mpgs from get go and it hasnot changed .
At first months ago I started thread saying same .
Others said 35-40 up to 50mpgs , good gosh !

Now after gaining more than 20hp along the way I did not lose anymore than it was already at but still think it can be better ?
 
I believe the light shouldn't come on until you only have 1.3gallons of gas from a 5.5gallon tank would be 4.2 gallons used. Sounds about right.

When mine is damn near the bottom of the red after the fuel light has been on i usually get to the gas station with .5(1/2)gallon left.
 
Roust84, Are you local to Seattle? If you are I am in Everett. Feel free to PM me and we can arrange a meetup to look at it. You might also try disconnecting the battery for a few minutes, then hook it back up and power on the bike. If it still persists there could be a loose plug somewhere that the computer is getting a wrong reading from.
 
TruWrecks said:
Roust84, Are you local to Seattle? If you are I am in Everett. Feel free to PM me and we can arrange a meetup to look at it. You might also try disconnecting the battery for a few minutes, then hook it back up and power on the bike. If it still persists there could be a loose plug somewhere that the computer is getting a wrong reading from.
Click to expand...

Unfortunately, I'm all the way down in socal. I will try to rest the ecu soon when i get a chance and see if that helps.
 
agentadam said:
Well actually the Calli tank only holds 5.0 gallons.
Click to expand...

Doesnt the Gen 2 have 5.3 gallons and the Gen 1 is 5 right? Atleast I thought I read that somewhere.

Anyway on my Gen1 I was getting high 30 to low 40 mpg stock. Now with a full exhaust, intake, and pc3 I am getting about 28-29. I must admit I am a little more throttle happy than before tho lol.

BTW Roust84 , did you go to bike night in City of Industry on thursday? I met someone there that had just bought a 09 Busa, I am just curious thats all.
 
Last edited:
roust84 said:
BTW what is white on the end of the pipes mean?
Click to expand...

Weird. White is supposed to be a very good sign, means you are burning nice and lean. I get above 50mph consistently, doing a lot of 2up riding, bike is bone stock and always have white build up at the pipe exits. At 20miles/gal you should see black. Sure you don't have a fuel leak?
 
White probably has more to do with the specific brand of gasoline you're using opposed to anything else. If I run any race gas at all through my vehicles it turns the tailpipes bright white. Put regular pump fuel in and they return to their normal black soot levels.

I can get 30 mpg riding mine like an idiot for an entire tank, or 40 if I ride really, really conservatively (shifting at 2k, etc). Disconnecting the ECU won't hurt, it most likely didn't like having the exhaust unbolted and may require the fuel trims to lean back out. Not sure how the 08-up bikes work, and how aggressive they are with adaptive values.
 
What RPMs are you at I have noticed that under 5k I get good mileage but over that it goes to poo poo :laugh: Remember your secondaries kick in at higher RPMs so they will dump alot of fuel. hope this helps
 
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run an entire tank and get an actual mpg. Running from 1/2 tank measurements can lead to some strange numbers and theories. Gas gauges aren't known for being incredibly accurate, think how long you can ride with gauge still reading completely full.
 
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