50cc vs 80cc and 2 vs 4 stroke gas consumption

[noslynx]

How would those combinations affect gas mileage? I'm guessing 2T will eat up more than 4T, how is the power though? And what figures should I expect?

 

[noslynx]

So, I got the following figures from sellers, 80 mpg 3.5 hp 80cc 2 stroke and 130 mpg 3 hp 50cc 4 stroke, are these realistic?

 

[Greg58]

I have both 48cc and 66cc two strokes, there’s a newer 79cc that is called a 100. My 48cc bikes get around 100 mpg, the 66cc about 75-80 mpg. Maybe someone with a four stroke will give their input.

 

[Greg58]

Fuel mileage can increase or decrease depending on gearing and how you ride.

 

[Sidewinder Jerry]

A great many factors must be considered to determine mpg. Engine size/make/type, total weight vehicle/rider, aerodynamics, drive system, vehicle speed and terrain.

I get well over a 150 mpg with my 33cc 4 stroke even though total weight is 350 lbs and I live in the mountains where 30% grade hills are common. At best my level ground speed is only 29 mph. What makes my bike unique is the triple chainring shift kit and 7 speed 34-13 freewheel giving me a reduction range of 66.79:1 to 16,25:1. The bike has 9 human/engine driven sequential non redundant ratios.

So regardless of what you desire to use its more so about your engineering skills as to what kind of performance you get.

 

[Greg58]

Good info Jerry, I've never jumped into the shifter bikes, unless the law has changed here we must have a single speed. I bet as long as I keept it down I would be ok.

 

[curtisfox]

Its always been single speed here also, unless you can do a automatic, actually don't think there is many states that allow shifting. But are doing it anyway......Curt

 

[Sidewinder Jerry]

For 10 years I rode the LandRider which shifted 7 human/engine driven gears automatically. I retired the LandRider and now ride a Sidewinder which has a triple chainring shift kit.

In saying that I've never once been pulled over by the police. Self built motorized bicycles are legal in Tennessee. We too have an automatic transmission clause; meaning no manual shifting. Here as long as you obey all traffic laws, stay off sidewalks while under engine power and stay under 30 mph the police won't bother you.

 

[Sidewinder Jerry]

With large people (200+ lbs), small engines (under 50cc) and steep hills (20%+ grade) you must have multiple drive ratios.

 

[curtisfox]

I believe here it 20 mph, and how many really obey that, especially when the cars don't LOL. Just a never ending thing, all ok except when you get a jealous cop........Curt

 

[Sidewinder Jerry]

I believe here it 20 mph, and how many really obey that, especially when the cars don't LOL. Just a never ending thing, all ok except when you get a jealous cop........Curt

Wisdom should tell a person 20 mph is still faster than walking. And is going faster than 20 mph on your motorized bike worth a fine?

 

[mapbike]

Ive always ran the 66 or 69cc engine (so called 80cc)

I've never paid real close attention to mpg on them, but I do know there was a time I road one of my bikes out to a local lake to visit one of my brothers who lives there on the lake and its just over 50 miles round trip from my home to his and I used about 3L of fuel going there and back on a bike with a 41T driven sprocket and a 26" wheel at max speed of 28mph on that bike since that is all it would do WOT on the flat and I road full thottle the entire way there and back.

So roughly 3/4 gal per 50 miles so Im gonna say I got around 75 mpg.

Ive never run a 4 stroke on a bicycle and I just got my very first 48cc CG in the mail a couple days ago and if all goes as planned I'll have it on a bike and ripping up the road tomorrow, so I cant testify to what kinda of MPG thw 48cc engines get, but I would think they should do a bit better than the 66 or 69cc engines if all else is equal.