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GlennR

"Smart Carb" ?

23 posts in this topic

Here's how i see it. An engine needs a certain ratio of air to fuel to run well (properly). Since engines aren't 100% effective, you can try to improve upon this aspect with no loss in performance. Any other means in which you try to gain "mileage" is going to hurt performance. Most people don't like to give up any performance!

Hmmmm..........just read up on that smart carb. Interesting at least! Some pretty wild claims!!

Edited by MANIAC998

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Here's how i see it. An engine needs a certain ratio of air to fuel to run well (properly). Since engines aren't 100% effective, you can try to improve upon this aspect with no loss in performance. Any other means in which you try to gain "mileage" is going to hurt performance. Most people don't like to give up any performance!

Hmmmm..........just read up on that smart carb. Interesting at least! Some pretty wild claims!!

My buddy has a fuel injected Husaberg FE570 that has quite a bit more HP, yet gets much better fuel milage riding side-by-side with my WR450.

I don't know what differences there are in the design, but he's getting more power & better milage at the same time.

Maybe I can tune my carb & engine a bit better, but I doubt that I'll ever figure out how to get from 30 mgp to over 40 mpg. That's a big jump, and my bike sounds & feels like it's running great.

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Actually, that's what I was trying to say. His Husaberg using fuel injection is more mechanically effecient than the WR with a carb. Part of it is the fuel atomization, another part would be the longer stroke of the Husaberg, etc. etc. A smaller engine working harder is almost never as fuel effecient as a bigger engine that isn't working hard at all. I've said it before, but I worked at Broome-Tioga (site of the AMA Nationals) one weekend during the NY State Championships, and had the pleasure of being a flagger on one of the big, bumpy, nasty rutted downhills. I could not believe my eye's as too how much fuel is dumped out of the carb vent hoses, when coming down that hill. Too put it mildly, it was astonishing as too the amount!!! When you hit a big enough bump, downhill/level/uphill, the floats in the carb react to the hit by descending into the float cavity from inertia. This displaces fuel, and the only place for it to go is out the overflow. Right there is another HUGE reason why that Husaberg gets better mileage!!!

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I hear what you're saying about the overflow tubes, but I've heard that even the 2012 WR450s don't get much better gas mileage. I'd have thought that the FI would have made a big difference. There must be some other "factors" that are against the WR's engine design...

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I have made many many measurements with my 2005 wrf-450 so i must say my opinion.I think that i have great milaege.So when i travel on the highway with my supermoto (15 front sprocket 45 back) with steady thrrotle at 115-120km/h =69-72 miles/h i spent 4,5-5 litres of gasoline= 1,18-1,32 gallons of gasoline.When i ride it on track i dont make measurements.I spent too much gas there ....i am full throttle all the time.My previous bike was a Ttr-250 and i spended more gasoline .I was suprised when i bought the wrf and when i have a conversation with my friends they say...I dont believe it...But it is the truth.I run 168 main 48 pilot and merge spring on my accelerator pump.I also have full exhaust system.Nevertheless the idea of getting a more efficient carb system like the smart carb is good and i hope someone can taste it ......

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Interesting review! It started out sounding like he was going to hate it, what with all of the mounting issues he was having. Then when he got it running, he was impressed! I haven't read all 12 pages yet, but if it was me having those mounting issues, I would've had to be pretty darn impressed with the performance to turn around my impression that much!! Thanks for the link HomeSkillet!!

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That's a great review thread. Sounds like a great design. Hope they can get the prices more affordable. Looking forward to hearing about them being tested on WR450s.

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I have made many many measurements with my 2005 wrf-450 so i must say my opinion.I think that i have great milaege.So when i travel on the highway with my supermoto (15 front sprocket 45 back) with steady thrrotle at 115-120km/h =69-72 miles/h i spent 4,5-5 litres of gasoline= 1,18-1,32 gallons of gasoline.

Can you explain your numbers a little clearer? I'm a little confused

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Why are you confused???I think it is clear.So i am going to write it again.My wrf-450 is supermoto and the gearing is 15 teeth frond sprocket,45 theeth back sprocket.I spent 4,2 or 5 litres of gasoline when i am going 115 or 120 kilometres per hour on the highway.

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I spent 4,2 or 5 litres of gasoline when i am going 115 or 120 kilometres per hour on the highway.

It is confusing because fuel consumption is measured as (volume of fuel) per (distance covered); for instance, 5 ltr per 100km, or 1 gal per 47 miles.

You are stating your fuel consumption as (volume of fuel) per (speed), which makes no sense.

So, what kind of distance do you cover with these 4.5 - 5 ltr of gas?

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You are stating your fuel consumption as (volume of fuel) per (speed), which makes no sense.

Indeed!!!...no sense at all.

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What kills mileage on a bike with an FCR compared to FI is the accelerator pump. Steady state riding, both bikes comprable (weight, engine, conditions) , the mileage should be the same.

An engine has an ideal, max power A/F ratio (across the rpm range). This is measured out the exhaust. So how it gets in is of little consequence.

So far, APT only does 2S. They are a year or more away from producing 4S carbs. Even then, a single circuit carb has never been successful for MX in the past, only drag and road racing. See the Edelbrock and Lectrons.

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It is confusing because fuel consumption is measured as (volume of fuel) per (distance covered); for instance, 5 ltr per 100km, or 1 gal per 47 miles.

You are stating your fuel consumption as (volume of fuel) per (speed), which makes no sense.

So, what kind of distance do you cover with these 4.5 - 5 ltr of gas?

OUPSSSS sorry my friend...it was my fault.....So the distance is 100kilometres with 4,5-5 ltr of gas when my speed is 115-120 on my trailtech vapor.Steady throttle on highway

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OUPSSSS sorry my friend...it was my fault.....So the distance is 100kilometres with 4,5-5 ltr of gas when my speed is 115-120 on my trailtech vapor.Steady throttle on highway

For people on non-metric systems, this translates to 47-53 mpg, which is really impressive! Usually the numbers people quote for WR is high-30s.

I wonder how unusual this number is. Is superbike28 a statistical anomaly, or is he merely judicious in his use of throttle?

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Why are you confused???I think it is clear.So i am going to write it again

I will remember not to question your posts. Thanks for your attempt to humor me and dumb it down.

Good thing Yamaha puts a reserve on the WR for challenged people like myself

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For people on non-metric systems, this translates to 47-53 mpg, which is really impressive! Usually the numbers people quote for WR is high-30s.

I wonder how unusual this number is. Is superbike28 a statistical anomaly, or is he merely judicious in his use of throttle?

My bike is a supermoto with 15 front sprocket and 45 back.My measurements are on highway on steady thrrotle.When i am on track i spent much much more gas.I was suprised also when i first bought my wrf-450 four years ago and my first trip was to my hometown which is 145 kimometres away and i was there only with one tank,and i have the oem tank.My previous bike was a ttr-250 with no mod's at all and it needed a lot more gas for the same distance.Is was hard to believe it myself but it was a nice suprice

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My bike is a supermoto with 15 front sprocket and 45 back.My measurements are on highway on steady thrrotle.When i am on track i spent much much more gas.I was suprised also when i first bought my wrf-450 four years ago and my first trip was to my hometown which is 145 kimometres away and i was there only with one tank,and i have the oem tank.My previous bike was a ttr-250 with no mod's at all and it needed a lot more gas for the same distance.Is was hard to believe it myself but it was a nice suprice

It is interesting to hear that a few WR450's get decent gas milage. I would sure like to know what the difference is.... :excuseme:

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