« previous next »
Pages: [1]   Go Down

Author Topic: F1 fuel range reserve fixed!  (Read 2305 times)

0 Members and 1 Guest are viewing this topic.

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,741
  • Saver of unloved motorcycles.
F1 fuel range reserve fixed!
« on: May 11, 2011, 10:22:10 PM »
My F1 is getting about 95 miles on a tank before reserve. It figures about 39 to 45  mpg depending on how hard I'm riding but the range seems a lot less than a K before reserve. About 2.5 gallons. is there more reserve on an F or smaller tank?
« Last Edit: May 13, 2011, 08:15:05 PM by Don R »
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline cookindaddy

  • I sure love this bike!
  • Expert
  • ****
  • Posts: 1,153
Re: F1 fuel range
« Reply #1 on: May 12, 2011, 08:12:59 AM »
Are you losing gas out the carb overflow tubes?

I have a 750K8 and last calculated 55 mpg and was pleasantly surprised. I think that the tank is the same size.
Logged
George with a black 78 CB750K (in Lion's Head, Ontario, Canada)

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: F1 fuel range
« Reply #2 on: May 12, 2011, 08:47:59 AM »
The F has a bit more fuel capacity. 4.8 vs. 4.5 gallons than the K.  Your results may vary depending on vintage. :)  I think it just hits reserve sooner but because of gearing differences the K may get a bit better mileage.  I seem to hit it between 100-120 miles.  Ultimate range seems to be 200-210.  Yeah, I ran it dry once. ;D
« Last Edit: May 12, 2011, 08:50:55 AM by srust58 »
Logged

Offline Steve F

  • I have "some-timer's disease" because I'm an
  • Old Timer
  • ******
  • Posts: 2,928
  • "To Ride Is The Reason, The Destination The Excuse
Re: F1 fuel range
« Reply #3 on: May 12, 2011, 09:44:02 AM »
On my F1's I would make it a rule to fill up at 100 miles so I won't need the reserve.  I probably can go 120 or so before hitting the reserve.
Logged

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,741
  • Saver of unloved motorcycles.
Re: F1 fuel range
« Reply #4 on: May 12, 2011, 04:37:52 PM »
I've been getting 95 miles but coming back from Topeka I got caught in the boonies and it didn't want to run on reserve, I choked it, fiddled with the fuel selector and it took off. I got gas at 112. Then 300 miles later it went on reserve at 93 started to run poorly and died at 103. We were going down a long grade. I'm sure there was gas left in it. I had tested the petcock last week and again today. Everything looks good. I ordered the screen assy that goes inside the tank at the petcock because the screen was missing. We filled the tank, ran it into a can then tested reserve and it worked OK. Not really sure what has been happening yet.
« Last Edit: May 12, 2011, 04:40:51 PM by Don R »
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 15,046
  • Bought her new 4/75
Re: F1 fuel range
« Reply #5 on: May 12, 2011, 05:38:27 PM »
Don,

I'd think you would do better than that. I'd also think you could get 175 miles on a tank at 40mpg. I'm thinking again that my reserve starts around 125 miles. 4.7 gallon tank according to one of my manuals with a reserve of 1.3 gallons. If you need a measurement of the tube height to compare with yours I can pull my relatively new petcock. Hey, at least you're not having to gas at 70 miles like the 650 I was riding.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline MasterChief750

  • Detonation
  • Expert
  • ****
  • Posts: 805
Re: F1 fuel range
« Reply #6 on: May 12, 2011, 05:45:39 PM »
im in the 120 mile ish range before reserve on my k
Logged
1978 CB750 K - Project Red Headed Step Child
1976 CB750 K - Drag Bike
Some things i know, others i dont.
I AM THE STIG
Sam is THE STIG
he said i can be STIG3 tho

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,741
  • Saver of unloved motorcycles.
Re: F1 fuel range
« Reply #7 on: May 12, 2011, 06:53:10 PM »
Right, my K3 would always go 120-125 no worries that's why I asked. I tested the petcock again and it worked fine, I'll ride 50 miles in the afternoon tomorrow. At least I got the clutch working well. Going to test it again now.
 Jerry, not sure how you made it. Some places we rode it seemed like there weren't very many stations.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,741
  • Saver of unloved motorcycles.
Re: F1 fuel range, Reserve fixed!
« Reply #8 on: May 13, 2011, 08:14:40 PM »
I fixed the petcock there is a small D shaped gasket under the fuel pick-up riser the gasket was twisted and made a small flap that almost covered the reserve fuel outlet. My local shop was able to get the kit with the riser, screen, seal, etc.
« Last Edit: May 13, 2011, 08:16:28 PM by Don R »
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 15,046
  • Bought her new 4/75
Re: F1 fuel range reserve fixed!
« Reply #9 on: May 13, 2011, 09:46:40 PM »
Great news! And at least we can still get a few parts for these F's.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)
Pages: [1]   Go Up
« previous next »