Bad Gas Mileage - Help!

[themaskcabana]

Maybe someone can help?

My bike:

WR450 2008

Stock Gearing

Throttle stop removed

Grey wire cut

Opened airbox

AIS has NOT been removed

TPS still connected

Dr. D Exhaust

Elevation 0-4000ft - Southern California.

JD jetting kit

Main 168 - I have gone one up and one down and it stutters. 168 is the best.

Pilot 45 - I went one up to 48 and didn't like it. So I went back down to 45

Red needle with clip in 4th position

Fuel Screw 1.5 turns out

R&D Power Pump with leak jet set to 40

PowerNow & PowerPlus

Acerbis 3.3 Fuel Tank

Now this is my problem. The thing is a gas hog. I know I opened it up, but it eats the gas up bad! I have a 3.3 gallon tank, and I only get about 60 miles on it before I have to hit reserve. That's roughly 20mpg. I also noticed this last ride that it bogged out a little in the 3/4 to full throttle as if it was too rich.

So I figure between losing gas fast and the bog that it's running too rich, but I'm not sure what to do, because if I go down in the main it starts to stutter.

Any Ideas? It seems like everyone with my year of bike is going with a 48 pilot and a 168 main with the JD Kit and similar setup/elevation. I was thinking maybe trying 48 pilot (I have 45 now) and instead of 168 main maybe stepping it back to 165. Additionally, REMOVING THE AIS.

p.s. It seems like I get horrible gas mileage whether I go fast or take it easy.

**Update**

I have checked the plug and it's black black. It looks like it's running rich. I also checked the Carb Float. The manual says 8mm and I have it right around 7-8mm. I am having a hard time measuring it because my calipers don't seem to reach (aren't long enough) all the way to the bottom of the float (pointed float bowl). That, and I'm not 100% confident that I am doing it right.

Edited December 1, 2009 by themaskcabana

[FORMA MOTO]

That mileage sounds about right, if you are using the IMS tank, which goes to reserve early (about 2.5 gallons) unless you lean the bike all the way over to the left get gas to the left side of the tank, and the petcock: meaning you have 40 miles on reserve.

[themaskcabana]

That mileage sounds about right, if you are using the IMS tank, which goes to reserve early (about 2.5 gallons) unless you lean the bike all the way over to the left get gas to the left side of the tank, and the petcock: meaning you have 40 miles on reserve.

I have the Acerbis 3.3. I don't think there's that much in the reserve. I looked in the tank and it was pretty much empty. I am not exactly sure what the reserve is, but I don't think it's much. I could be wrong though.

[WR450FGreg]

.

Yep, I usually get about 80-90km or so before reserve from my '08 WR450F, so your 60 miles (100km) is pretty good!

These things are gas-guzzlers unfortunately.

I haven't found a solution to it yet.

Greg

[HEELER]

Yep they suck the fuel and there is not much you can do about it i have found. The way i went was change of tank a put a 15.5 litre safari rallye tank on mine and luv it. Great tank they come in black,blue and clear they r not top heavy and i get about 140 - 160 ks all depending on how i ride it and that is normaly hard. Nothin worse than startin too enjoy your ride when you gotta turn around for more fuel. They start at $450.00 up. Have a look at the one on my bike and the web is www.safaritanks.com. Best of luck

[YamaLink]

Presumably you are not a lightweight rider AND you ride pretty aggressively all day long?

[themaskcabana]

Really? Everyone is getting that bad of gas mileage? It seems like it’s got to be at least a little better than this? Maybe you guys are right? My buddy has my same tank but on a KTM 2008 530EXC and he gets 80miles before he hits reserve.

What about the fact that it looks like it’s running rich. I pulled my plug and it’s black black. I also checked the inside of my header and it’s not running with black goop or anything, but it’s got a nice thick layer of black stuff like it’s running pretty rich.

Does removing the AIS do anything for that?

Presumably you are not a lightweight rider AND you ride pretty aggressively all day long?

I do usually ride pretty aggressively, but it seems like I get crappy gas mileage even when I’m puttin around.

[BajaFool]

Hate to chime in here, because there are so many variables that can influence gas mileage. I have owned a 2003 and a 2006 WR450F and currently own a 2008 WR450F. All of these bikes regularly average 30 MPG on single track trails that are hard pack. I can usually count on 35 MPG on a combined single track, two track and some roads trail ride. If the ride is mostly all road, I can count on 40 MPG. This is not unusual by the way, my fellow KTM EXC riders are in the same range as I am on identical rides. My (our) riding is in northern Baja California and ranges from no track, nasty single track, jeep roads and graded roads consisting of sand, gravel and hard pack. One thing I have learned about theses bikes that will kill gas mileage is long stretches (miles and miles) of riding in lower than 5th gear and lots of riding in the sand. All of my bikes have been geared no more than 1-2 teeth larger on the rear sprocket from stock and the front sprocket has always been the stock size. And, I gave up on riding in the desert years ago.

My 2008 has all of the free mods and is jetted to the factory stock carb configuration for the 2004 WR450F, my 2006 was jetted this way also. My 2003 was very close to this same jetting spec also. Stock exhaust systems on all of these bikes by the way.

I had the Acerbis 3.3 gal. tank on my 2003 and 2006 bikes and reserve was not much, maybe .3 gals. I have the Clark 3.4 gal tank on my 2008, that Acerbis 3.3 gal tank is beyond ugly.

Trying to calculate gas mileage based on gas tanks is odd, especially between different models of motorcycles. Use miles per gallon.

[themaskcabana]

Hate to chime in here, because there are so many variables that can influence gas mileage. I have owned a 2003 and a 2006 WR450F and currently own a 2008 WR450F. All of these bikes regularly average 30 MPG on single track trails that are hard pack. I can usually count on 35 MPG on a combined single track, two track and some roads trail ride. If the ride is mostly all road, I can count on 40 MPG. This is not unusual by the way, my fellow KTM EXC riders are in the same range as I am on identical rides. My (our) riding is in northern Baja California and ranges from no track, nasty single track, jeep roads and graded roads consisting of sand, gravel and hard pack. One thing I have learned about theses bikes that will kill gas mileage is long stretches (miles and miles) of riding in lower than 5th gear and lots of riding in the sand. All of my bikes have been geared no more than 1-2 teeth larger on the rear sprocket from stock and the front sprocket has always been the stock size. And, I gave up on riding in the desert years ago.

My 2008 has all of the free mods and is jetted to the factory stock carb configuration for the 2004 WR450F, my 2006 was jetted this way also. My 2003 was very close to this same jetting spec also. Stock exhaust systems on all of these bikes by the way.

I had the Acerbis 3.3 gal. tank on my 2003 and 2006 bikes and reserve was not much, maybe .3 gals. I have the Clark 3.4 gal tank on my 2008, that Acerbis 3.3 gal tank is beyond ugly.

Trying to calculate gas mileage based on gas tanks is odd, especially between different models of motorcycles. Use miles per gallon.

No, are you kidding me? I appreciate the feedback. I actually ride in Southern California between desert type situations and more technical trail riding. I have stock gearing. I didn't change anything on it.

That's what I figured, I should at least be getting 30mpg worse case, but it seems like I am getting more like 20mpg. Now, I know that the bike has been beefed up a little with the new jetting, the carb mod, and some other stuff, but it just seems like I should be getting more than 20. This is also supported by the spark plug (crusty black), low gas mileage, exhaust, and the slight bog on the last ride, that it is running rich. So I am figuring that maybe that's where my loss of gas is going, but it seems like the jetting I have is the one that runs the best.

Have you removed your AIS? Did it make any difference?

[PBDBLUE]

Well I've ridden with BajaFool and he's really slow! Nah just kidding BF. In my experience the mileage varies widely with the type of riding/style. If I'm pushing it real hard or under heavy load (i.e sand wash, etc) then I usually get in the mid 20's. If I'm just cruising it's more like the mid 30's. 20 does seem a little low though the jetting you've listed is not out of line. Remember these bikes have a pumper carb so every time you twist the throttle it's dumping fuel straight in. That's true of all the 4 strokes that use the FCR carb.

[KennyMc]

Well I've ridden with BajaFool and he's really slow! Nah just kidding BF. In my experience the mileage varies widely with the type of riding/style. If I'm pushing it real hard or under heavy load (i.e sand wash, etc) then I usually get in the mid 20's. If I'm just cruising it's more like the mid 30's. 20 does seem a little low though the jetting you've listed is not out of line. Remember these bikes have a pumper carb so every time you twist the throttle it's dumping fuel straight in. That's true of all the 4 strokes that use the FCR carb.

Pretty much on point. It really depends on the terrain. I just did a 105 mile loop from Cal City to Last Chance/Nightmare and around to J-Burg and never went on reserve running a 3.2 gal IMS with 168 main/48 pilot.

[SXP]

I rode from Barstow to JoBerg (visited all the crash sites along the way), including one WFO run across Cuddyback, had 105 miles on the clock at the gas station and the bike took 2.8 gallons to fill up. I run the IMS 3.1g tank.

Main 165

Pilot 45

JD Red 5th notch.

07 YZ450F pipe

My plug is always black when I inspect it.

The inside of my header also looks like what you describe.

It appears YMMV (literally ).

[rkwfxd1]

I've got the Yamaha AIS removal kit and included jets in my '09. I hit reserve at about 38-40 miles with the stock tank. I have a Clarke tank and 52T rear sprocket comming. After I test those out I may lean outthe jetting to 168/48 butthe bike seems to run really nice as is.

[themaskcabana]

Pretty much on point. It really depends on the terrain. I just did a 105 mile loop from Cal City to Last Chance/Nightmare and around to J-Burg and never went on reserve running a 3.2 gal IMS with 168 main/48 pilot.

That’s funny, that was actually my last ride where all this happen (cal city - jawbone and some surrounding areas. First time I rode there). I was testing out the new tank (acerbic 3.3) and jetting, and I only made it 64miles before I had to go to reserve. My buddy was riding just as hard as or as easy I was and he made it roughly 90miles before going to reserve. He has the same tank as I have, but for a KTM 530EXC 2008.

That’s why I feel like there is something going on here, and I just can’t seem to explain it. Jetting seems about right in comparison to everyone else. The only difference that I can tell is, I have the R&D power pump on my carb. I do have the powernow and powerplus in my carb as well. I am not sure if that makes that much of a difference.

Am I way off base here in thinking that I’m losing a lot of gas?

[themaskcabana]

I rode from Barstow to JoBerg (visited all the crash sites along the way), including one WFO run across Cuddyback, had 105 miles on the clock at the gas station and the bike took 2.8 gallons to fill up. I run the IMS 3.1g tank.

Main 165

Pilot 45

JD Red 5th notch.

07 YZ450F pipe

My plug is always black when I inspect it.

The inside of my header also looks like what you describe.

It appears YMMV (literally ).

Hmmm? See and I can't seem to get that. I get 60miles on about the same. Same area too. Soooo now I am really confused. I guess all I can do is keep tweaking things and see what works.

I appreciate the feedback.

[BajaFool]

Maskcabana,

PBDBLUE, re-emphasized my observation regarding riding in the lower gears and lots of sand. These conditions will really suck gas. Also, if you constantly roost or blip your throttle, that pumper carb will squirt a too rich mixture of fuel air into your motor. As I said in my original post, there are lots of variables that go into the MPG equation.

Looking at your mods, I can not provide any advice to you regarding your carb jetting as currently configured, because you removed and replaced a perfectly good factory exhaust system that was well engineered to match the engine characteristics of your engine, quiet, actually quite light and paid for. Then you added things that have questionable advantages to performance (no doubt strong comments will soon follow:foul:).

If you really want to research and solve your problem, I would suggest that you go back to square one and take off all of that after market stuff you put on your motorcycle (Dr. D exhaust, PowerNow, PowerPlus, JD Jetting Kit and R&D Power Pump). Then jet the bike to the 2004 carb specs. Only make the following changes, everything else remains stock: MJ #165; PJ #45; needle OBDWR (in the Yamaha parts book it is the STANDARD needle) and Fuel/Air turned out 1 3/4 turns.

The AIS installed or not should not be the cause of your problem. I would take it off (mine is off), just for weight saving. But, don't throw it away -- remember big brother CARB is lurking in the shadows.

As for the AIS removal, I bought vacuum plugs at the auto parts store and made a diamond shaped piece of aluminum sheet as a blank off plate. The jets and needle in the GYTR kit are way too rich.

The 2004 jetting was the best jetting combination so far for the 450 motors. There were few complaints about it on this forum or that I have heard from others over the years. It has worked for me quite well, and I ride from sea level to 5,000+ ft without changing jetting. Also, really think about gear ratios. If you are riding for long distances in less than 5th gear, kiss your gas mileage goodbye.

[SXP]

I rode from Barstow to JoBerg (visited all the crash sites along the way), including one WFO run across Cuddyback, had 105 miles on the clock at the gas station and the bike took 2.8 gallons to fill up. I run the IMS 3.1g tank.

Main 165

Pilot 45

JD Red 5th notch.

07 YZ450F pipe

My plug is always black when I inspect it.

The inside of my header also looks like what you describe.

It appears YMMV (literally ).

I forgot to metion, I run a one tooth larger front sprocket (14T) for a 14/50 combo. And, I second all the comments above about ridding style. I'm very smooth with my throttle inputs, rarely spinning the tires and always ride the bike in the highest gear allowable and just take full advantage of the bikes low-end torque/grunt.

[Baja trail Rider]

Yes you should get about 30-35 easy trail riding.That what my 07 wr 450 gets,with a 180 main jet,and 14 on front.I did have to change the IMS tank to a Clarke 3.6 tank.I have made it over a 100 miles on that tank.

[viking50]

You guys think you get bad gas mileage? My son's '03 KTM EXC 300 gets 15 mpg! That's 45 miles out of a 3 gallon tank. Yea, I know it's a 2 stroke. Riding in Michigan, all sand single track. I get 35 mpg out of my 2000 WR400. We have a nickname for the WR's that ride in our group....Exxon Valdeez! Cause the 2 stroke KTM's in our group are always siphoning off of a WR out on long rides!

[Yama4fitty]

I am in the same boat here on the fuel consumption...er I mean GUZZLING. I gots an 08 WR450 with AIS removed, GYTR needle clipped 4th, 168 main, 48 pilot, grey wire cut, pipe insert and air boot removed, stock tank, Tusk fuel screw 1 1/2 turns out.

I get about 42-48 miles on a tank riding Dove Springs/Red Rock areas before going to reserve. At bone stock I would get about 60-65 miles.

My buddy's 07 with all same mods, except his has a Q4 pipe, was getting same miles (60-65) as me when I was bone stock. Now with my mods I am even more worse off!!

Everyone else with YZs and even a CRF150 don't even go to reserve like I have to on rides. AND they ride around more than I do from here to there while on these rides.

How and will sprocket changes effect my fuel mileage? From what I am reading, I need to stay in a higher gear and go easy on the throttle as much as possible right?

Definitely going to get a clarke tank though.