Topic: fuel mileage for a 1979 cb650

[MMICAFE]

ok i have a 1979 cb650 and i really need to know what my fuel mileage is with the petcock in the on postion and the capacity in the reserve postion i desperatly need to know this as i am going to be riding to california this coming up march so please let me know as soon as possible

[fuzzybutt]

it all depends on how hard you ride it, how fast you go, how much weight the motorcycle will carry (both the rider and gear) tire inflation, condition of the motor and carbs, state of tune and even, in small part, the brand of gas you use

[MMICAFE]

all i wanna know is the basic fuel mileage im not stupid i know that those things factor in the mpg im not a newbie rider

[fuzzybutt]

no need to get testy mate. you didnt state you knew all the variables so i erred on the side of caution.

[MMICAFE]

ok if i was being testy you would know it

[Gordon]

Jeez, Fuzzy!  Why can't you just tell him what he wants to know ASAP without bringing up all these things that would affect the outcome in a real-world situation?   He's important and in a hurry! 

Trust me, you don't want to see him when he's testy!! 

[Hush]

Funnily enough I have a 1979 CB650 too and I asked this same question weeks ago without a reply so maybe its something no one knows?
The 650 is the ginga haired bastard child of the Honda brigade and unlike the 750, 500, 550, 350 SOHC 4's not every single breathtaking fact is known about them.
Only guys like Soos who go against all tradition and insist on trying to modify to the extreme these orphans, knows much about their secret workings.
Until someone figures it out, I'll just have to keep sloshing the gas tank around with the cap off to see if I need to fill up.

[cb650]

Seems most people get 50 or so.  I get around 60mpg and a best of 67.  All on a 80 or 81 so with the 79's bigger tank you can go farther that your butt will most likely want to go.

[Soos]

Well the '79cb650 has about 5 gallon tank, be glad you don't have a '80-82, they are like 4.2 gal or something just quoting outta my arse, but I think those #'s are close...


At 65mph on a flat run area, a average of 45 is "normal" from my experience for a '79cb650.
I have gotten as low as high 30's to mid 60's for MPG.
All depends on your throttle use and shifting habits.



On my last long trip(Provo,UT to Las Vegas, NV) I averaged about 40 mpg.

Keep an eye out for other drivers if you must ride at dawn or sunset.
I would suggest pulling over to watch them for an hour before riding again.... cage riders can't see well with the light in their eyes....




Just for "reassurance" I filled up every 150 miles when I could.

The longest I have gotten off of one tank(including using reserve), about 240 miles....before I chickened out and stopped for gas.

If you are worried about running outta gas, search out a 1 gallon gas can, and strap that baby on somewhere.



Be careful at sea level with those carbs, try not to run WOT for too long.
Those PD50 carbs are jetted lean to begin with, and at sea level, they will be even leaner.



l8r

[Duke McDukiedook]

You guys didn't figure for if you are riding into a headwind or a tailwind, I'm sure that affects mileage a bit.

[cb650]

Really    Never thought of that  .   Acually last time I got 67 I was semi lost. Knew where I wanted to go but many deadends so lots of back tracking nostly on gravel so wind wasnt in the picture.   Ok I usually average 60 going to the bank "and back" to the store "and back" $#$%* like that.  My worst is usually 55 when I might have a headwind on a trip one way or run a little harder. 
If memory servs me the the 79 tank is 4.5 and the rest are 3.5.   Have streached out mine (80/81)to 150 miles a tank and thats when the a$$ wants a rest to.  Anymore way before then.