Power and fuel mileage?

[Kcizik]

Is it asking too much to get both? I was looking at the SSW package deal, and really who could turn that down? But I know with the FCR my fuel mileage would suffer, after all it is a pumper carb.

I ride my bike a lot (it is my only vehicle here), and fuel mileage matters as gas is expensive here. I'm really more concerned about the day to day mileage on the road. When I'm out playing with it, fuel economy is not my concern.

So what would be the way to go? I know 50hp and fuel economy will probably never go in the same sentence. How much can you do to this thing before your MPG's go out the door?

How can I have power and still get good city/highway mileage?

[npm]

The single largest contributor good or bad to mileage is your throttle hand. Turn the volume up, mileage goes down. Even a built motor can get pretty good mileage if you control how hard and far you turn the throttle. Problem is once you get used to the rush the extra power will give it will be hard to have the discipline not to rip on it all the time.

[Noble]

You can easily get 50 mpg with either the stock carb or the replacement FCR even with other engine mods. It is all in how you ride it .

[UFboostedgator]

Welll....I average about 48 or so with my current set up. Stock motor, 3X3 and MRD SSW. It dipped since I put the off road tires on (they are heavier) and I also use mine as a daily driver when it's not raining. I will be doing an FCR in the near future and gas mileage is the least of my concerns. It is nice to get a weeks worth of gas for like 10 bucks. I will also go bb as well but either way we will still get better mpg's than most cars...

[Kcizik]

I'm very aware of the relation between the right hand and fuel economy. But still my point stands, no one with a fcr that i've seen is getting close to 60MPG. I'm no stranger to vehicles that give you a rush either, I know it is addicting. But most of the time when I'm on the road, my wife's on the back, it's all easy cruising. When I'm by myself, it's all different.

Plus that and gas stations aren't exactly everywhere, I still need to get 120 miles out of a stock tank sometimes.

[npm]

I don't think that anyone with the FCR installed really cares about fuel milage but you are correct I don't know of anyone reporting 60 mpg with that carb. If you put one on and baby it around to see what kind of milage you get be sure and report back.

You could always go up in tank capacity if you need to go farther between gas stations.

[GTi4lifee]

so all engines are just heat engines.

The name of the game is get it in, get it out. A good, high flow air filter and a full exhaust is the threshold of power and MPG. Anything else would be the drop in MPG and gain in power.

In all honesty, when you make a more efficient engine, your reliability drops.

Engineers work hard to find that threshold of reliability and power. The stock setup, on models SM and S, are designed for freeway use. E was sacrificing the reliability for its brute force. If you want the best MPG and the most reliability, watch your wrist angle (throttle setting). If you want a little more power and increase mpg SLIGHTLY, then a good high flow air filter (K/N) and a full exhaust. Thats it.

[Kcizik]

just curious, MRD is definitely on the books. What really got me thinking was the BB kit, I know some have tried keeping the Mikuni with it. I wonder what the end result of that was. I can stand to loose a little economy, I just can't go down into the 40's. I'll keep looking.

[Craigo]

When ridden sensibly my 41mm fcr equipped 485 SM gets 22 km/l and the Big bore 39mm fcr E gets 18km/l...both with similar gearing..

Here the higher hp engine is delivering better fuel economy figures ....but it has had the head flowed...

The theory here , as I see it, you are not twisting you hand as much to achieve the same performance....

That is if one can resist the temptation ....

[JUNURE]

With the 3X3 & JD jet kit my friends and I get better gas mileage than stock. I added the MRD/SSW & Hotcams and the gas mileage is still about the same, 56 to 64 MPG, with stock carb. It might get better if I was to just cruise. I have found like CraigoDRZ400sm said, I am making more power and don't have to twisting my hand as much to achieve the same performance.

[One Less Harley]

You'll be very lucky to get 120 miles out of your stock tank and setup.

The FCR will not return good mileage...period. When I had the FCR mileage dropped off and no it wasn't due to excessive throttle. Since you seem to be concerned about mileage just do the 3x3 mod and the JD jet kit. It's pretty responsive with those mods. If you need a range of 120miles look into getting a larger tank like the IMS 4 gal.

I had the FCR and was setting the bike up for the TAT, but since the FCR (42mpg at 55-60mph) wouldn't allow the range I needed with four gallons of fuel, the stock carb went back on. It was a good choice. The stock returned 52-55mpg (60-65 mph) and at slower speeds 58-65mpg. Just not worth it to me.

BTW 15-44 gearing, 434 BB kit, 3x3 mod, JD jet kit, stock exhaust. Sorry I can't tell you about the power increase of the 434 BB as it's always been on the bike. Power/torque is acceptable for a 434cc bike. I found the FCR to be too responsive to throttle inputs, especially when standing on the pegs on rough terrain.

Oh yeah the FRC cost serious cash....and the additional fuel will cost you too. Plus the FCR is harder to get on and off the bike!!!

Edited December 15, 2011 by One Less Harley

[DEC]

I get 50-54mpg doing "normal" around-town type riding, with FCR carb, 3x3 and a Yoshimura RS2 exhaust. Street tires on 17" wheels. Obviously I could do a lot worse if I wanted but I don't ride like a grandma either. I've gotten as good as 57 before but with mostly straight-line cruising around 60mph. I'm not too heavy (155lbs or about 70kg) which helps. I've read a few MPG threads and it seems many people get the same or better MPG with the FCR. Of course, you can't believe everything you read on the internet

[Kcizik]

Right now I get 110 miles per tank comfortably without hitting the reserve. I don't want to get another tank, especially since it will cost me a fortune to get it down here. I just would like to stay in that range. Thanks for all the input. I like craigo's theory!

[Bikedude189]

last i clocked was 60mpg on an E (with FCR) so to all the people who say it's ridiculous, it's not. mostly cruising at 45-50 but on the way back i did a max speed run, and there were a couple of trails in the middle. so mileage would have been better had it been all road miles (about 80 round trip)

[One Less Harley]

last i clocked was 60mpg on an E (with FCR) so to all the people who say it's ridiculous,..... better had it been all road miles (about 80 round trip)

Nothing ridiculous about my claim, 1st hand experience. Lucky you, not my case and I was careful to stay off the throttle. With the stock carb one can just ride like normal and not trying to get more mileage out of the FCR. At least that's my experience, no changes in ridding style but carb, one variable change and the variable effected mileage. I wonder what your mileage would have been w/ the stock carb, better than the FCR I'm sure.

The FCR will return more power but at a cost of mileage, plus something that was pretty irritating it's a PITA to work on at least putting it back on. The stock fits easily without having to push and pull the carb to get the intake and air boots in place. Given people don't remove and install the carb all that much, but for me it's another compromise. It's so much easier to mess w/ re-jetting the stock carb or adjusting the needle as the carb only has to be rotated on the manifolds.

I know with most of the people here that the issues w/ the FCR aren't that big of deal, most want more power, to heck w/ the short comings. I'm more of the ADV rider type. I look for practical, long term, ease of maintenance, and simplicity, more what one needs when off the beaten patch for a week or two. Yes some improvements are good, but some others make improvements but at a cost of one or more of the above.

[jackrook]

No engine mods, cruising at 55mph still gets me 120 miles per tank.

[Sideways1]

434 big bore,39mm FCR MRD/SSW/3x3 light highway and town driving stop and go I get 75 miles and have to hit reserve. Time for a bigger tank...

Dan

[pbblaster]

I got 57mpg on my last ride. My S has a header, FCR and hotcams. I was doing mostly back roads averaging 55 mph. I weight 220lbs.

[Kcizik]

434 big bore,39mm FCR MRD/SSW/3x3 light highway and town driving stop and go I get 75 miles and have to hit reserve. Time for a bigger tank...

Dan

Ya definitely can't do that!

I guess because of the circumstances and country my bikes in, I'll stick with the stock carb. But the MRD, I can definitely do with one of those

[Noble]

Lots of things affect fuel mileage. My set up, my use, my style, I get the same with FCR or BSR. 55 is normal either way. In my head I use 50. In reality it is rarely much under 60.