Topic: Average MPG on your Honda CB750's Report

[kaptainkid1]

So I wanted to get people average miles on there Honda CB750's and wanted to know all the mods, Picture if possible, year and mpg.
Like everyone here on this forum, I did a few changes over the year and I'm getting bad gas mileage or mods have really burned up my fuel economy. 
Mostly city 80/20 Highway but since I live in LA, CA I do a lot of lane splitting and I should consider my driving more like city 50/50 Highway. I generally keep the bike moving even in traffic above 30 mph most times.




Here are my numbers: I'm hammering the bike for most times but these mpg's means I'm flooring all the time which is 50% of daily driving since I like to ride fast and loud!

1975 Honda CB750F Super Sport: Stock exhaust, stock gears, I do have Vintage Shoei's panniers weighing about 50lbs. Only extra weight I carry all the time full of stuff.
All Stock: 105main/40idle jet: 36mpg
Next Mod: Cut Airbox 112.5main/40ide Jet: 32mpg
Last Mods: Cut Airbox, DynaTek Ignition, 120 main/40idle jet: 26mpg(Even though I love the extra power I really hate these CAR MPG's I might as well drive a civic.)

What's you're baby getting on the road?


 

[seanbarney41]

every 750 I have ever had gets between 40 and 50 mpg.  I usually run 17 front/ 48 rear sprockets or equivalent.  Mostly have only ever adjusted main jet...I have one bike running open Kerker and HA breadbox with 135 mains and it still gets  40mpg and it's the exact same color and model as yours.  I don't really ride on the freeway but frequently average 65+ mph on mostly straight Michigan back roads.  If you are spending lots of time at 80+ mph on the freeway and then lots of time with heavy throttle on, no throttle coasting while lane splitting, I can see getting that kind of mileage.  could try 18/46 sprockets but its gonna hurt acceleration something fierce.

[Don R]

 My 76F had 110 mains, stock idle jet and a stock airbox with a 3 1/2" glasspack baffle in an 18" stainless truck tip. It was very sensitive to the float levels. At first I got under 95 miles before going on reserve after a lot of float adjusting and new undrilled jets it got 125/130.

 The PO had seriously tweaked the floats and drilled the jets. He was running no muffler. And was not an awesome mechanic. Probably was my favorite 750. I went to 18/48 later on but sold it soon after for K0 money.

[kaptainkid1]

According to http://www.fuelly.com/motorcycle/honda/cb750k
1975 Honda CB750 average 33mpg and I read somewhere 1975 Honda CB750 had bad mpg because the stricter smog laws and the later 70's got worst as standards got harder and harder.
Here is list of bikes from 1971-1979 Honda CB750 mpg's.

These are real world mpg's.

[kaptainkid1]

every 750 I have ever had gets between 40 and 50 mpg.  I usually run 17 front/ 48 rear sprockets or equivalent.  Mostly have only ever adjusted main jet...I have one bike running open Kerker and HA breadbox with 135 mains and it still gets  40mpg and it's the exact same color and model as yours.  I don't really ride on the freeway but frequently average 65+ mph on mostly straight Michigan back roads.  If you are spending lots of time at 80+ mph on the freeway and then lots of time with heavy throttle on, no throttle coasting while lane splitting, I can see getting that kind of mileage.  could try 18/46 sprockets but its gonna hurt acceleration something fierce.

I posted a screen shot of fuelly.com and I think if you are getting mpg over 40's on cb750's you're really driving very safe and stop very infrequently. I wish I could get over 40mpg.
It seems like a lot of people who post on fuelly.com are getting mpg's close to my reality.

[scottly]

I did an accurate measure of my average MPG over a distance of 700 miles plus, on my portion of the 2013 Relay . At the start of the ride, I measured the level in the gas tank with a dip-stick. I logged the miles and gallons at each fuel stop, and at the last fuel stop, carefully filled the tank to the same level on the dipstick. I averaged just over 50 MPG, at speeds over 70 MPH, as well as lower speeds going uphill through mountains and small towns, and a lot of time with nasty headwinds.

[seanbarney41]

every 750 I have ever had gets between 40 and 50 mpg.  I usually run 17 front/ 48 rear sprockets or equivalent.  Mostly have only ever adjusted main jet...I have one bike running open Kerker and HA breadbox with 135 mains and it still gets  40mpg and it's the exact same color and model as yours.  I don't really ride on the freeway but frequently average 65+ mph on mostly straight Michigan back roads.  If you are spending lots of time at 80+ mph on the freeway and then lots of time with heavy throttle on, no throttle coasting while lane splitting, I can see getting that kind of mileage.  could try 18/46 sprockets but its gonna hurt acceleration something fierce.

I posted a screen shot of fuelly.com and I think if you are getting mpg over 40's on cb750's you're really driving very safe and stop very infrequently. I wish I could get over 40mpg.
It seems like a lot of people who post on fuelly.com are getting mpg's close to my reality.

you certainly got one thing right...I don't stop much.  I usually ride at least 100 miles every time the bike comes out.

[PeWe]

My CB750K6 has always had a fuel consumption of 6L/100 km. (40mpg) Stock as well as modified.
Less consumption require really slow and boring riding. (45mpg)
NO throttle twisting nor passing cars. Speed around 50-80 kph (30-50 mph)

Nowadays mostly around 7L/100 km (33mpg). This include a few fun throttle sequences up to 100-120 mph 

[Grabcon]

Okay here let's see if I can get it right. Build completed April of 2014. I have many bikes so this one has only 4500 miles on since the rebuild. 1976 CB750F, 836cc with a Web 63A cam. Carbs are set up with 38 slow jets and 105 high. Needles are set to second clip from the top. Running a factory 1978 CB750F header with a MAC slip on. Stock air cleaner. Points ignition.

Gearing, becaused I used many parts from other CB models such as  a 1991 CB900f and CB1100F I used the standard rear that came with the CB900F. Front 17 rear 44.

I also ride at elevations of 5000 to 11000 feet. I would suspect that at lower elevations my mpg would be in the tank as it is with my other bikes.

Average mpg is 44.28. Best was 57 plus.

Most of the time there is a fair amount of throttle action and gear changing. Living in Colorado not much is flat or straight. Try to hit 100 each ride just for fun.

[ekpent]

 I'm in with the 40-50mpg club also.

[evanphi]

So Average is about 6L/100KM, but there's a few low ones near the winter time when poor quality gas gets put in. I'd say it is actually closer to 6.5L/100KM.

So... call it 36MPG. I can do wayyyy better though if I am riding with my vintage club. They ride slow and for long periods. Easier to baby the throttle. I got over 50MPG on one group ride.

[millla03]

My mostly stock 72 750 consistently gets 43 mpg. Gains a couple mpg when travelling and doing sustained 65-70 mph.

[tlbranth]

1970 CB750 K0. Mostly stock w 4 into 1 exhaust. I average 45 mpg.

If you're lane splitting, you probably won't have to worry about mileage for too long.

[kaptainkid1]

1970 CB750 K0. Mostly stock w 4 into 1 exhaust. I average 45 mpg.

If you're lane splitting, you probably won't have to worry about mileage for too long.

Apparently, you live in a state where it's illegal. Do you know all over the world it's legal and done every day with no accidents? You look old enough and I'm sure you rode bikes in the 70's and I'm sure you didn't wear helmets all the time. One would stay you wouldn't live long either and look at that you're still alive.

I've noticed anyone who's getting higher mileage generally don't live and ride in cities. Who's not stuck on stop and go traffic commuting? Honestly, I should stop putting miles on my classic but I love taking her out and WOT where ever I can.

[seanbarney41]

Dude, I live in Michigan...there really isn't any traffic.  Rush hour is pretty tame when hardly anyone has a job, lol.  Watch out for that farm equipment, though!

[HondaMan]

My K2 gets about 30 MPG in commuting traffic (25% in minutes, sitting at stoplights...) and nudges over 40 MPG on hiway trips in the mountains, 42-44 on the interstate headed to lower altitudes east (like Kansas/Missouri). Keep in mind, the F0/1 bike is geared low to take advantage of the higher RPM cam in those engines, and the primary drive was lowered to help get the revs up into the torque range.

BUT...is you are running the tire-air PSI numbers that are printed on the labels on your bike, that's losing LOTS of MPG...today's tires are all a different design. With unloaded bikes, the typical rear 17" tire on that bike should have no less than 35-38 PSI in it, and the front should be sitting above 35 PSI as well. My 50 sports the Vetter fairing and air forks up front: I run 38 PSI up front and 38 rear unless carrying my wife, then it is 40 rear (my rear is 18", so yours should be slightly lower).