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Mods for better fuel economy?

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Hello Thumpertalkers:

Looking for some advice on how to improve the fuel economy of my DRZ. Why you ask? Well, I have plans to do some long distance off-road touring and don't want to run out of fuel in the middle of nowhere and need to be rescued.

I already have the Clarke 3.9 tank installed, and city driving on the work commute I get 190 km (118 miles) before reserve. Average fuel economy has been working out to between 33 and 37 miles per gallon.

To me this fuel economy seems a bit low, considering all the posts I see with 50 mpg fuel economy on this board.

I am wondering if something I did led to the poorer-than-average fuel economy. :applause:

Mods that may have an impact:

1. Clarke 3.9 tank. Probably no impact on economy, just range.

2. 14 / 48 gearing. I like the faster acceleration, but this may be contributing to higher RPMs. I am doing mainly city commuting in the winter (sub 70km per hour) so the gearing is kind of fun.

3. 3x3 airbox mod.

4. I believe the previous owner cored out the exhaust.

5. I re-jetted the bike with the JD kit - 155 main, 25 pilot, cold weather needle on 4th clip, and fuel screw at 2.5 turns (all as per the JD instructions).

Unfortunately I did not calculate the fuel economy before completing these mods, so I do not know if my mods have affected economy at all.

Any ideas would be appreciated as to how to improve on the fuel economy - I would love to get up to 50 mpg to increase my range and also to gloat at my cage driver friends.:applause:

Thanks in advance for the help!

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Well.... put on 16/38 gearing, undo the 3x3, put a 1/4 outlet on the pipe, take out the BSR 36 and get a BSR 28, that'll do it.

But seriously, the gearing when cruising causes the RPMs to be higher than they have to be, using more fuel. The airbox and jetting typically all contribute to a richer fuel mixture being used, also consuming more fuel. However, a stock carb with the jetting and airbox should be able to get 50 MPG.

You might want to seriously consider changing the gearing to a more road friendly ratio, like a 15/44 or shorter.

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I would go to stock gearing and tires.

After I installed the FCR I actually noticed better mileage. When I can stay away from the wheelies. Also, the gas tank full adds a little more weight.

What kind of DRZ? S or SM?

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Its an S model, year 2000. An oldie but a goodie.

The hooligan driving probably has something to do with the economy too - its too much fun to twist the throttle!

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You are not going to get any better than what you got. Drive a little more slowly and that make the biggest difference. Unless your carb needs cleaning being a bit older those stock carbs are good for fuel econo,

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Last tank was 42 mpg. Stock 01 E and that was about 50/50 dirt street. average mph was 45. Stock has given me the best mileage. Usually the mpg's are in the mid 40's.

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Last tank was 42 mpg. Stock 01 E and that was about 50/50 dirt street. average mph was 45. Stock has given me the best mileage. Usually the mpg's are in the mid 40's.

I have a new '06 with 300 miles (no mods). I was finally able to get a check on my last ride. I did about 30 miles off road, and 50 on road. I ended up getting 60 mpg.

I was starting to sweat bullets as I approached 80 miles, because we were far from gas and I had read from others that they hit reserve near 80 miles.

From my calculations, I figure that I can get about 120 before reserve, and 150 max on one stock tank.

Does that sound right to anyone else?

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From my calculations, I figure that I can get about 120 before reserve, and 150 max on one stock tank.

Does that sound right to anyone else?

Not to me, when my "S" was stock, the best I ever got was 110 miles to reserve, sitting at 50 mph on the motorway.

Normal riding, reserve at 90 miles, max.

FCR, big bore, and a stage 1 inlet cam, normally 80 to 85 to reserve.

If very careful you could ease it out to around 90 but that is no fun :applause:

Neil. :applause::lol::cry:

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I have a new '06 with 300 miles (no mods). I was finally able to get a check on my last ride. I did about 30 miles off road, and 50 on road. I ended up getting 60 mpg.

I was starting to sweat bullets as I approached 80 miles, because we were far from gas and I had read from others that they hit reserve near 80 miles.

From my calculations, I figure that I can get about 120 before reserve, and 150 max on one stock tank.

Does that sound right to anyone else?

Same here 06S, 60 MPG when not having fun. It would be 100-110 before reserve, then if I take it easy I have another 25-30 to go.(Not actually proved, just calculated)

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1st thing,put the stock gearing back on.you should be getting between 45 and 55 mpg(1 gal = 4.546L)with the mods you have got.i would also make sure the valves are set within there limits.fuel millage has a direct conection with your right wrist

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60 mpg stock, and 45 mpg for dirt riding sounds perfectly good to me... :applause:

On my street ridden only SM, the overall cumulative average for over 3,300 miles is 66.2 mpg... with the worst mileage at 61.1 mpg and best at 72.8 mpg.

The bike is bone stock except for being lowered, modded E exhaust, and 16/41 freeway gearing.

Actually, the less mods you do,

the better your mileage will be...

...but for most people,

there's no fun in that. :applause:

Greg

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But seriously, the gearing when cruising causes the RPMs to be higher than they have to be, using more fuel. The airbox and jetting typically all contribute to a richer fuel mixture being used, also consuming more fuel. However, a stock carb with the jetting and airbox should be able to get 50 MPG.

You might want to seriously consider changing the gearing to a more road friendly ratio, like a 15/44 or shorter.

william is right on....ive ridden my bike (hard) the first 160 miles....have used about 3 1/2 gallons of gas

less mpg then greg(^) but thats my riding style...wfo

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I have a 03 stock "S" with the Clark 3.9 and I hit reserve at 225 miles. When you hit reserve you better have a gas station in sight, only about 30 miles max on reserve.

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225 til reserve? Over 50 mpg?

I can only dream of numbers like that.

Lots of suggestions above to try the stock gearing again. This is what I will try, its easy to adjust.

No-one seems to be getting such poor fuel economy as I am. Its only partially to do with a twisty throttle hand. I have tried to lay off it...

Thanks for all the help!

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225 til reserve? Over 50 mpg?

I can only dream of numbers like that.

Lots of suggestions above to try the stock gearing again. This is what I will try, its easy to adjust.

No-one seems to be getting such poor fuel economy as I am. Its only partially to do with a twisty throttle hand. I have tried to lay off it...

Thanks for all the help!

Yep, right now I have the same gearing as you, 14/48 and get 33mpg. 66 miles until reserve (E model).

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1) Mount a Dakar style front fender and get rid of the MX one

2) Use a large tank with air holes on the sides to allow the wind through (don't believe Clarke has these)

3) Use a scott oiler and MX chain without o-rings to reduce friction

4) Mount a Nology spark cable in order to more economically burn the fuel (most people say this is BS and I agree)

5) Configure your carb to run lean in the mid rpm range

Take care,

Noppy

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