Fuel Mileage

[AussieSteve]

I've got the billet head arriving in a day or so and decided to take an extra-long ride today to make comparison easier. Filled the 2L tank to the bottom of the filler tube and thought I'd be set for about 50km, (30 miles), at least.
A 20 mile ride should be no drama, I thought. Got most of the way through my ride and putt putt nothing. Out of fuel.
With a good number of steep hills and a couple of little monos etc, mileage was more like 30km, (18 miles). 6 miles, (10km) to pedal home. Great fun on these hills with my legs.
The engine is a 66cc HT, standard throughout. What sort of mileage do you guys get, with a few hills etc? Does this sound low? It's running a little rich, but still...
(An extra bottle in future, or one of those 4-litre tanks)
...Steve

 

[thuginfc]

i run for hours on a tank days even rough estimate i get bout 30-35 miles a tank i too run a little rich

 

[AussieSteve]

Many hills in your area?
A lot of reasonably steep ones today for me. For the first time, I'd fully relaxed, felt confident that nothing would break and was really enjoying the ride. I was a bit heavy-handed with the throttle on the hills. That wouldn't have helped.
Still, I was planning to re-tune, (leaner main jet, lower slide needle), when the new head goes on in a day or two and that'll probably change things a little.
Being in a semi-rural area, long rides are a necessity sometimes, so I'll consider a bigger 4 litre tank AND a water bottle full of mixed fuel, I think. 5 litres will get me as far as I will ever want to go.
...Steve

 

[Al.Fisherman]

Just the other day my son and I went to Oak Mountain State Park here in Alabama. We filled up (80cc's) at the bottom of the mountain and also up to the filler neck. The round trip was more then 20 miles (32.19km). I got better then my son. He is 135# (61.37 kgs) and I'm 200# (91 kgs). 80% up hill to the top (did quite a bit of coasting down). Upon finish my tanks backbone (hump for crossbar) was covered in fuel while my son's was just above the fuel level. Standard tanks on both.
Pelham, AL elevation is 460 feet whereas the mountain top is 1,300 feet. Bottom to top is about 7 miles and we started the trip from 6 miles outside the park where I parked my truck.

 

[flashstar]

My fuel mileage was really poor until I realized that I was leaking gas from the tank. I fixed the leak and now I can hardly tell that I used any fuel after a tough 6 mile ride.

 

[AussieSteve]

Hmmm. Thanks for the input guys. It seems that mine's running super-rich. (No fuel leaks)
I put a gasket in the top cover of the carby about a week ago and since then the mixture's been much richer.
Noticeably, too, the idle dropped right off. I had to turn the idle screw in heaps further to keep it idling properly. I'm still running 15:1 oil, so the fuel/air mixture will be richer still when I go to 20:1.
The new main jet will help and I'll drop the slide needle to it's lowest setting, (clip in the top notch). The standard jet is 0.79mm, so I've got a #76 to try and a smaller one coming. The billet head might like a richer than normal mixture, too.
... Steve

 

[cabinfever1977]

i weigh 120lbs and im getting 90 miles per tank.

 

[Al.Fisherman]

i weigh 120lbs and im getting 90 miles per tank.

90 miles per tank ?????
What engine are you running?
Is it stock?
And if a HT, how are you measuring those 90 miles?

If so, that is GREAT as I've never heard of such mileage out of a stock HT even the advertised "up to 150 miles per gallon"

I think those up to 150 miles per gallon engines are with the bike suspended and idling.

 

[AussieSteve]

Hello again Al and also cabinfever1977. I didn't answer this earlier, for obvious reasons.
Wow, 90 miles / 2 litres. 72 km/litre. Boy have I got some work to do. Any tips?
Let's be sensible here.
... Steve

 

[flashstar]

I just measured my mileage and I'm getting about 45 miles per tank. I'd say that this is average.