Fuel Economy

[toojeep4u]

So I have had my Connie for a little over a year now and love it.  This is my first bike so it has been a learning experience for sure.  I have made a few improvements to it, but I am still not happy with the poor mileage I see.  My running average is less then 32mpg.  True I live only 2 blocks from work so most of my driving is very short, but even after a 1400 mile tripe this summer I only saw 40mpg at my best.  I have the 2-min mod installed by Steve and tuned for economy.  I am using a 1.75 inch piece of foam. in the right side of the airbox.  Tire pressures are correct.  I have a 25" Clearview shield.  Installed stickcoils this spring and did a valve adjustment then too.  I am amazed by the mileage others are getting on their bikes and would like to get closer to that.  Any ideas folks?  Thank you in advance.

[T Cro ®]

Wow that is sucky MPG .... I get better than that with my DynoJet kit which can turn a bike into a fuelaholic! Are you sure that you got no fuel leaks?

[snarf]

Over oiled air filter? How do your plugs look?

[RFH87_Connie]

Connie can drink some gas if you let her.  I just moved to a different house 10 miles from work, before this, I was only 2.5 miles away.  Before I moved, during the week, I would be lucky to get 30 mpg.  I constantly found myself ripping around town.  Dash to work, dash out to lunch, go home.  Now I find I have been ridding a little saner, and I am getting about 35 to 36 during the week.  Short trip driving was killing my mileage just like a car does.  As for distance, I used to get only about 36 mpg.  Again, it was my fault.  After making a concious effort, I could get 41 to 42 mpg when I wanted to.  Coming back from Myrtle Beach this summer, following the families u-haul truck back home, I got 45.5 with only me on the bike and no top box.  When my wife and I go out for a day long ride (2-up) I usually get about 41 to 42 mpg consistantly.

It's all in the wrist most likely.  But of course it could be mechanical too.

[DarrellB]

If I keep her under 70 I get almost 46. If not about 40.

[Two Skies]

For me, I find that 70ish MPH is the break point for my mileage.  If I keep 'er below 70 on my commute to work, 45+ mpg is very doable.  Lately, though, the traffic has been doing the 75 MPH pack mentality, so my mileage has dropped a bit.

I'm also at about 4250 feet in altitude, which plays in to the higher mileage figure a bit.  Higher altitude = lower air density = less fuel used, to a point anyways.

It's been a bit harder to judge mileage lately, as most of my local gas stations have went to pre-pay, and now I'm having to estimate how much fuel I need beforehand.  Hence, I haven't been topping off my tank as much, and hence can't get a good reading of my MPGs.

[Centex]

Do you ride the 2-blocks to work and park it going and coming most days?


If so, that's very rough duty for any vehicle, IMHO, since things never get fully heated-up, condensation isn't blown out of pipes, etc.  Very low mileage for that duty is not a surprise to me 


The 40mpg on your trip is at least in the range of reasonable if you were then finally enjoying your Connie at speed 

[DannyL]

I just filled up this morning and I calculated 36MPG (US) I do 80 miles a day back and forth to work. I have a sweet spot I like to drive at and it's 80 mph. this could account for the not so great gas millage. My carbs are in terrible shape, but I'm not really to throw in the towel for the season yet. I think Steve might adopt them and heal them this winter....

[Nosmo]

2 blocks to work?

That's walking distance and that wouldn't even get my legs armed up.  Your Connie will never  even get up to operating temp so the carbs won't function well, etc., etc.

Like others have posted, there's a MPG break somewhere around 70 MPH or so.  I normally cruise at around 60 - 65 (yeah, I'm one of THOSE guys) and get around 45 MPG.  I do NOT have Steve's carb mods, but I DO have his 7th gear mod and the cam timing changes for low-end torque.  If I work the bike one the back roads the way it was designed for....maybe 35 MPG or so.

It's mostly all in the wrist, but a large windshield can cost you also, it takes fuel to push a big barn door down the highway at speed.

You tire life will vary accordingly also.

[DannyL]

but I DO have his 7th gear mod....

So do I! However to be fair, I think I actually has to be installed ON the bike for better MPG's! 

[toojeep4u]

Do you ride the 2-blocks to work and park it going and coming most days?


If so, that's very rough duty for any vehicle, IMHO, since things never get fully heated-up, condensation isn't blown out of pipes, etc.  Very low mileage for that duty is not a surprise to me 


The 40mpg on your trip is at least in the range of reasonable if you were then finally enjoying your Connie at speed 

I agree that the two blocks is not good for the bike, but it shouldn't effect my mileage on my long distance trip should it?  That 40 mpg I mentioned was only one tank, the others were in the mid to low 30's.  Can carb vacuum levels make this kind of difference?  I remembered that I never balanced the carbs after getting them back and installed.

[connie_rider]

toojeep, what shape are your carbs in? Have you checked the fuel levels? Have you checked compression?

While the short distance you describe is not optimum to gt good mileage, you may have another problem.
I suspect you have a carb with too high of fuel level.
Another thought would be to check and see if you have a cylinder that was hydrolocked somewhere in the past.
A slightly bent rod would decrease HP and reduce mileage. Check compression or measue to the top of the pistons to check this.

But,,,,,,  don't get excited. I suspect you have a carb with too high of fuel level.

Ride safe, Ted


Ride safe, Ted

[Summit670]

I just filled my stock 87 and it got 37mpg but I had a lot of higher speed operation.  I usually get around 40-42 general driving if not heavy on throttle.

One thing to keep in mind, when figuring gas mileage with such a small tank it really matters that the tank is filled to the exact level each time and that is hard to do.  The best way to figure average fuel mileage is to calculate it over the course of many tanks (using the actual mileage on the bike and actual gallons from the receipts).

Also, for more precise mpg you should account for speedo error, which I don't so my mileage is overstated by 5% or so.

[toojeep4u]

I haven't checked the fuel level since I got the carbs back from Steve.  The carbs themselves should be in excellant condition.  I keep a running average on fuelly.com and I fill to the bottom of the neck each time.  I am heavy on the throttle, but when on the highway I like to cruise at a steady pace.

[kzz1king]

My 86 never got that great of mileage. Last winter I rebuilt the brake calipers, new wheel bearings and a new windshield. I picked up about 4 mpg, from 33-36 average to 37-42.

I just got an 01 and it gets 40 when I ride it like I owned it! If I ever kept it around a steady 70 I will probably see 43-45. Maybe I will try that.......next year

[connie_rider]

If Steve set your float levels they are right!
My 86 never got good mileage. I tried numerous fixes, never solved the problem.
On trips with other Connies i consistentlygot 3-5 mpg less than they did. I assumed the bike was justtired and compressiojndown. Tried float levels, etc.
On my 03 I get betetr mileage. But not as good a others report.
Probably my throttle hand!

Ride safe, Ted

[Pfloydgad]

Well....
MOBs and I have had a few discussions concerning this. Lots of ideas about many different things to try, do, and experiment with.
I have settled with 2 things I do once or twice monthly. First, I confirm the correct positions of the float levels.
Not at all difficult with either the Clymer manual or the Mama Kaw Shop Manual.
2nd. , I drain the bowls and direct pour ISOHeat (Red Bottle) through the carbs from the fuel feed hose.
 I catch the ISO with the drain tubes on the bowls,and funnel in
through a cheese cloth to filter, and do this maybe 4 to 5 times.
I am very comfortable with these 2 things, and I am getting 50 mph when doing the speed limits, and I have never seen less then 46 mph even when doing slightly more then the recommended speed.
I am religious about tire preasures, and I don't do any holeshots.
I just passed 76k, and "Hey Baby" is purring like a content kitten on a warm lap.
Don't know if this will help, but it sounds like your open for suggestions.
Ride safe all, and ATGATT please.
Greg

[Cybercraig]

There are so many thing affecting gas mileage it's tough to say. On a 3,200 mile trip this summer I averaged about 35mpg overall. That's with 110lbs of gear cruising 80-85mph across the west. If you are running into the wind it will cut your mileage. When you start running above 70mph the fairing is pushing a lot of air out of the way and your mileage decreases. Running ethanol-laced fuel cuts your mileage. Running a 17" rear wheel cuts your mileage. The best I have ever done was a cool day across Kansas at 70mph with no luggage and I hit 49mpg. I haven't been able to see that since. 

[Gitbox]

I just did a trip to NJ and back. 300 miles on one tank. I never hit that range before so I had to take a picture. Six gallons to fill up makes it 50mpg. Not too bad for 70-80mph most of the way.


I have SISF's 7th gear and torque cams.

[Steve in Sunny Fla]

That 2 block trip will kill your economy. you're getting what i would expect, based on what I've heard from others who do short trips and stoplight to stoplight riding. Any time the bike is idling , it's sucking fuel but not moving.  It's getting 0 mpg.
   I just came back from a trip to Barber Motorsports. My worst tank of fuel was when we were doing the trip from camp to barber, banging on the backroads, then sitting idleing in a long line waiting to get in. I remarked to Stevej that the idling was going to kill our mileage. He gave me a confused look. Most folks don't realise that warmup time and idling kill economy. Go for a real ride, run a few tank over tank fills, you'll see the mileage steadily increase - the engine is warm and functioning in it's most economical state. Steve