Propane?

[Reveeen]

I'm sitting here looking at a stupid scooter (aren't all scooters stupid compared to a "real motorcycle"?) a Volano (but a Benzhou, same thing as a Saga DLX, or for my/our American friends: A Hunter Eagle chassis, or Vento Phantom, TNG DR150, Tank Racer, Roketa Fiji, Falcon, Lance GS-R 150, Baja SC150, Jonway Epsilon 150, JMstar Eagle, Moto Fino MF150QT-10D Longbo LB150t-12 Adventure, Yiben Cool Classic, MotoMojo Taz 150, Jonway 150T-12 scooter), and I got to *thinking*, that for a super economy effort, I could run the thing on propane. Propane costing around $2.50/gallon vs gasoline at $5.50 a gallon. I know there is about a 20% power "hit", but I can try to pick up the power in other ways, so it should be ok.

This is in the *thinking* stage, as there is still a lot of snow here (leaving next week one hopes), and as yet, I have not determined if the thing even runs. I guess I am asking for any thoughts on this, other than "she's gonna blow" kind of thoughts, I am sure I can do this safely.

[RageHardIntoTheBendies]

It can be done

http://www.hobotraveler.com/2009/01/propane-motorcycle-in-peru.html

I'm sure I have a seen a propane powered snow machine at one point also.

[Reveeen]

The last time I was down in the Dominican Republic, besides seeing soldiers in the streets with AK47's, I saw scooters powered by what I assume was propane. The tanks were 20 lb BBQ tanks, but they could have been containing butane/methane, or natural gas, instead of propane?

[Weldangrind]

Natural gas would be 'horrible. It's only about 30% as efficient as gas.

What kind of carb would you use with propane on something so small? Can you find a piston that would take advantage of the high (equivalent) octane rating, rather than taking a 20% hit? Do you think the guides could handle full time propane use? How about the valve seats?

I think this is a really cool plan, especially if propane is cheap in your area.

[katoranger]

I'm interested. I wonder how far a 20lb tank would go.

[Reveeen]

A 20 lb tank is roughly 5 gallons of propane. If you were getting, say 80mpg on gasoline, I would expect getting 320 miles per 20 lb tank (20% less, or 64mpg).

There are ways to get that 20% back, timing changes, increased compression, probably closer to 15%, of the 20%, or a overall loss of 5%.

The trouble is: small

I have been involved in conversions of big stuff, even played with propane injection into a diesel, the stuff needed here is small. What this means: it is highly unlikely "regular" propane conversion stuff, that can be had for pennies on the dollar used (out of old taxi's, police cars, trucks, and fork lifts) will work at this, it will need "new" small pricey stuff.

It will also be troublesome at low temperatures. Conversion from a liquid to a gas requires energy. Under normal conditions the energy is taken from the surrounding air, or from forced component heating with engine coolant, an air cooled engine has no coolant to steal energy from.

[katoranger]

I don't know if it would save enough to pay back on a scooter.

[Reveeen]

I don't know if it would save enough to pay back on a scooter.

Neither do I.......

I'm *thinking* about $200-250 to convert (I haven't started digging yet), fuel price of 1/2, it appears if I was planning to spend $400-500 on fuel over the summer it would be a 100% pay back.
This would translate into 5700-7100 miles. Not taking into account fewer services, and if gas does not get more expensive than $7 a gallon (I am expecting at least $10 a gallon by summer).

Other stuff going on in the background here:
Fuel tax increase of 4 cents a liter at midnight.
Another 5-6 cents a liter on Thursday midnight.
"They" (being the government) have mandated E85 fuel in all grades but premium by May 1st. Premium Friday morning will be $7 a gallon.

[FastDoc]

That's not good news at all right there...

[Cal25]

What about the small engines used on floor buffers like they use at Walmart type stores? Would they have similar fuel systems?

With the fuel milage a scooter gets out of the crate, I would be very reluctant to try something that complicated to save a litle money. Would be a fun project to follow though.

[Reveeen]

What about the small engines used on floor buffers like they use at Walmart type stores? Would they have similar fuel systems?

Yes... similar, but the thing is: where do you find one "junked" somewhere to strip the fuel system off?

I can buy enough stuff to convert a car/truck at a junkyard for a $50 bill, but this, because it's small, needs specialty stuff, that is not just lying about. I have not started looking though, something may turn up (once the snow goes), that I can cobble together. $200-250 is not an unreasonable amount of money though, but because the scooter in question gives around 100mpg the pay-back is slow.

It is not overly "complicated", more "different", than hard or difficult. You are basically dropping a controlled propane leak into the venturi of a carburetor.

[FastDoc]

What about leaving the scooter as is and converting your car or truck? Could you switch back and forth to gas again depending on availability?

[MICRider]

Another small motor (well, relatively small) that's often powered by propane are the motors used on oil pump jacks... They use them here until they can run power to the oil lease, then they replace them with electric motors. I haven't done any googling to see how common they are though, or what the actual hp of them is.

[katoranger]

The last time I had my grill tank filled it was about $20. Its currently cheaper for me to use gasoline in my scooter.

[lego1970]

I don't know if a gas engine will run off propane without modifications, but I do know that's how you check for a manifold or intake leaks. Take a bottle, open it all the way and start blowing around all the manifold, carb/throttle body/intake gaskets. If the engine makes a different pitch (normaly lower, if memory serves me right) then you have a leak. That's all the info I have on the subject.

[katoranger]

Propane conversions are pretty common on gas engines. They use a different carb that adapts to a propane tank.

http://www.propanecarbs.com/small_engines.html

http://theepicenter.com/tow102899.html