Topic: CB750 K5, 37mpg

[Schnell]

Does that sound right? Most of those miles were at 60mph, 4200rpm, in 5th gear

(New sohc owner here)

[Jerry Rxman Griffin aka MuthaF'er]

I'd like to think you'd be more like 45mpg. Good tune with good jetting? How clean are your plugs?

[Mo]

How much do you weigh? 

jk I have no idea if that would effect mpgs...

[scottly]

Sounds low to me, too. The first thing I would suspect is an old paper type air filter element.

[2wheels]

Is that 37 US mpg or imperial mpg?
If US it's a little low.  if imperial something is wrong.

Air filter and check timing. lets see a picture of all 4 spark plugs.
Tire pressure too

[Sdsbassist]

Any mods?

[Stev-o]

Sounds a little high. Try keeping it around 7,000 RPM and 75+ mph, much more fun that way!

[Reganator]

How much do you weigh? 

jk I have no idea if that would effect mpgs...

It would... But I doubt it would do that much.

[Terry in Australia]

I'm betting your bike hasn't been ridden very far for awhile. When I put my Goldwing back on the road the first tankfull seemed to go through it pretty quickly, but the second one was better, and the last tankfull returned 40 (mostly highway) miles per US gallon (if I did my sums right) which is pretty good for a 1200cc engine pushing 750 pounds of road sofa. Do a couple of long rides and check again. Cheers, Terry.

[70CB750]

I get 35 average on a gallon commuting - long term statistics - but that's local roads.

Godzilla run 300+ miles a day I averaged 44mpg.

[Schnell]

Thanks for your replies! I calculated using US gallons.  At 250, I could lose a bit of weight. I'll change air and oil filters today and take a peek at the plugs. Bike is new to me, runs well, but I'll do the valve clearances and check timing soon.

[KRONUS0100]

i have a windjammer 3 and i push 285 easy, i get maybe 32mpg 90 percent of time on country roads and hiways.  main highway extended run gets maybe 37 to 39 mpg when i dont have to be shiftiung all the time

[Schnell]

A bit of history on this bike. It was owned by my brother in law and we had gone on a couple of tours, he on this Honda, and I on my same vintage BMW 900. I could get 190 miles on my smaller gas tank, while his range before hitting reserve was about 130 miles. So this bike has been a consistent gas hog. It has been sitting in his garage for the last 10 years and with no time to ride, he sold the bike to me last fall.

[Reganator]

unless?

That'd do it.  I remember reading a study that suggested the US could could reduce fuel consumption by something like 2% by loosing weight.  No offense to the chunky munkys out there, I'm pushing 270 myself.  I'm working out though and going on a diet.  Maybe I should run an experiment and track my results.

[Bankerdanny]

I would think 37 was at the low end of normal. I was able to break 50 once on my 550 during Relay Rally 1 during a long highway stretch running 65-70mph.

[hoodellyhoo]

With the fairing on my K6 and blasting around on the freeways at 5,000rpm (70mph)  I'll get about 40mpg. Maybe 43mpg if I'm cruising closer to 60mph. With the fairing off I'll get up around 45 mpg. One of these days I'll replace my old ignition parts and replace the paper air filter with a K&N and see what happens.

[Terry in Australia]

A bit of history on this bike. It was owned by my brother in law and we had gone on a couple of tours, he on this Honda, and I on my same vintage BMW 900. I could get 190 miles on my smaller gas tank, while his range before hitting reserve was about 130 miles. So this bike has been a consistent gas hog. It has been sitting in his garage for the last 10 years and with no time to ride, he sold the bike to me last fall.

The K5 and R90/6 had the same size fuel tank, (18 litres) unless your BMW had the Euro spec 22 litre tank, which all the Aussie BM's had. BMW's were easier on fuel though, with only 2 cylinders and 2 carbs, so that's no surprise either.

The best fuel economy I got from a big bike was from my 1985 Harley Sportster with only 1 carb, but that was a good thing, considering the size of a Sporty's fuel tank.

Losing weight and getting fit is over stated. In the old days the only fat people were kings, and they lived much longer than the skinny-arsed peasants who made up their kingdoms. Don't sacrifice your "Royal" proportions for better fuel economy mate, some people are just jealous because they have no royal blood and can't grow a decent gut.

If you do decide to get fit, do it slowly, my ex-brother in law was a cop, and he told me once that "The Morgue is full of track suits", which was a reference to the guys who've had a heart attack and died while trying to get fit again. I think dying while trying to lose weight and get fit would really piss me off! (Oops, wrong thread..........)      

[Reganator]

Losing weight and getting fit is over stated. In the old days the only fat people were kings, and they lived much longer than the skinny-arsed peasants who made up their kingdoms. Don't sacrifice your "Royal" proportions for better fuel economy mate, some people are just jealous because they have no royal blood and can't grow a decent gut.

If you do decide to get fit, do it slowly, my ex-brother in law was a cop, and he told me once that "The Morgue is full of track suits", which was a reference to the guys who've had a heart attack and died while trying to get fit again. I think dying while trying to lose weight and get fit would really piss me off! (Oops, wrong thread..........)      

Lol, I'm in no super big hurry.  Problem is I was heavy once, then lost weight, then gained it back.  It will be nice to be more attractive to the fairer sex and all of that, but vanity isn't my main motivation.  I've got two:  1, a large very nice wardrobe of clothing I'll be able to wear again, 2, I have terrible heart burn.  Seriously, I had heartburn when I was heavy before, when I lost weight I didn't have it anymore and when I gained it back the heartburn came back.  Just that by itself is enough to get me to want to trim down.  I also noticed some benefits in terms of energy, and it was easier to bend over and tie my shoes, every day stuff like that, but mostly it's the heartburn and the fact that I won't need to dump a bunch of money on a new wardrobe.

[scottly]

On last year's relay, I averaged 52 MPG over 561 miles, cruising at 60-65 MPH for the most part. It would have been better if not for the 40 MPH head wind from Parker to Joshua Tree.  That's with an 836, and,of course, Webers.

[Terry in Australia]

Lol, I'm in no super big hurry.  Problem is I was heavy once, then lost weight, then gained it back.  It will be nice to be more attractive to the fairer sex and all of that, but vanity isn't my main motivation.  I've got two:  1, a large very nice wardrobe of clothing I'll be able to wear again, 2, I have terrible heart burn.  Seriously, I had heartburn when I was heavy before, when I lost weight I didn't have it anymore and when I gained it back the heartburn came back.  Just that by itself is enough to get me to want to trim down.  I also noticed some benefits in terms of energy, and it was easier to bend over and tie my shoes, every day stuff like that, but mostly it's the heartburn and the fact that I won't need to dump a bunch of money on a new wardrobe.

No worries, keep an eye on the heartburn thing, I weigh more than you and I rarely get heart burn, and one other thing my brother in law told me was that a lot of corpses that he picked up had packets of "Quick Eze" (antacid tablets) in their pockets. The inference being that a lot of folks were having heart trouble, but mistaking it for heartburn. If you're in any doubt, go and see a doctor. Cheers, Terry.

[KRONUS0100]

best mileage bike i had was a 90 GS500e.................55mpg consistent no matter how hard i rode it.  next was the 81 GL1100I............my wife is my size and 2 up headed to hogrock in'06 i got 52mpg out of it.  Wife is upset now beause there is no room for both of us on the 750F....need another 'wing

[Terry in Australia]

Yep, every home should have at least one 'Wang.........

[Stev-o]

Yep, every home should have at least one 'Wang.........

Great pic Terry, but disagee. Every home should have at least one SOHC and a Z1!

And to Reganator - That "heartburn" sounds like acid reflux to me. Get it checked out, my wife suffers from this and just had her gall bladder removed.

[Reganator]

Yep, every home should have at least one 'Wang.........

Great pic Terry, but disagee. Every home should have at least one SOHC and a Z1!

And to Reganator - That "heartburn" sounds like acid reflux to me. Get it checked out, my wife suffers from this and just had her gall bladder removed.

Yeah, it most likely is GERD or reflux.  As I loose weight it will improve.  I can manage it fairly well by avoiding certain foods, taking antacid, and not overeating.  I really hope to get it canned soon.  It's a real PITA, and I've got it at the moment.

[Terry in Australia]

Great pic Terry, but disagee. Every home should have at least one SOHC and a Z1!

Ha ha, being an ex Z1 owner I can't argue with that mate, and technically, a 'Wang is a SOHC4, so you won't get an argument from me! Cheers, Terry.