76 cb750- 68mpg and counting

[Odin]

well kinda, also i know this isn't the motorcycle thread but i figured it was a success story too.
1976 cb-750 super sport- I removed all turn signals, got strait handlebars that are very low, removed the air box and replaced it with single filters, new oil and filter, cleaned the carb with a leanish tune idle set at 500rpm, strait headers to a single pipe no restrictions-
but the main part was my driving style turning the engine off all the time and gliding everywhere+ never idling, always ducking, keeping the rpms below 2k, and only riding on surface streets no highway.
I put 1 gallon in after letting it idle till dry and so far its made it 68 miles, not really an average but seeing how good i could get when my actual average of regular driving is around 40-42 and when i get on it more like 30-32
everything i have learned on here is paying off

[euromodder]

Originally Posted by Odin

strait headers to a single pipe no restrictions-
but the main part was my driving style turning the engine off all the time and

Ain't that a bit too loud ?

From my m/c days, I recall an unrestricted exhaust leans it out even further, don't you get lean-mixture issues with it ?

[Frank Lee]

Sounds like an awful lot of credit being given to the straight pipes, which we have pretty thoroughly discredited for cars. Glad I don't have to listen to the damned thing.

[Odin]

Originally Posted by Frank Lee

Sounds like an awful lot of credit being given to the straight pipes, which we have pretty thoroughly discredited for cars. Glad I don't have to listen to the damned thing.

surprisingly it is very quite- the headers make two sharp turns which really muffle it well, at idle it is hard to tell if its running more than 10 foot away. plus each pipe from a cylinder is around 1" ID and the collector pipe is 2" adding to restriction too just no baffles

[Varn]

Your engine is no doubt tuned for max torque about 6000 rpm. Next time you modify, make your straight pipe longer, at the back of the bike, turn the pipe up like a Diesel truck. Don't worry about those who get 50mpg, they are gas hogs.

[Ford Man]

You should be able to improve it a little more by changing sprocket sizes next time you have to replace them. A few tooth difference shouldn't slow a 750 down much on take off, but would lower cruising rpm's.

[NHRABill]

Are you running any sort of fairings? wind screens? I am going to make one once I clear a project out of my garage.

My bike ran much stronger when I put in a quieter baffle (Big City Thunder). I believe I also increased my mileage but have no proof of fuel gains because it is near impossible to measure due to no gauge and a million variables @ the pump when filling up.

Wish I could figure something out to measure the fuel ... but its too much trouble.

[Odin]

Originally Posted by NHRABill

Are you running any sort of fairings? wind screens? I am going to make one once I clear a project out of my garage.

My bike ran much stronger when I put in a quieter baffle (Big City Thunder). I believe I also increased my mileage but have no proof of fuel gains because it is near impossible to measure due to no gauge and a million variables @ the pump when filling up.

Wish I could figure something out to measure the fuel ... but its too much trouble.

Despite how much a wind screen and body panels would help i just love the raw cafe racer style look too much to put any wind shields on.. maybe someday. As for a smaller rear sprocket, I got one about a year ago for better highway and have never gotten around to installing it, soon


I ran out at 84 miles- which is over double my usual FE, this time i topped off the tank at 4.1 gallons and my goal is 300 miles, we shall see