clean burning moped

I just purchased a used 1999 Derbi Hunter from a friend. I work for an environmental firm and thought how great it would be to putt around town in a gas sipping moped. After I bought it, I found out it isn't much of a gas sipper as I thought it would be. I think it gets only 50 mpg or so. Does anyone know if this is accurate? My car gets about 35 mpg. Not much difference considering one has more than 10 times the horse power and more than 10 times the weight. I also found out the thing smokes like crazy. Someone told me to put synthetic oil in it but the guy I bought it from said that's what he put in it. You can see the smoke coming out the tailpipe when it idles and it seems to float past me and into other cars. I would be pissed if I was next to a smoker like this. Any suggestions as to how to minimize the smoke? Finally, does anyone have any idea of how to convert a moped to perhaps burn propane, ethanol, or even biogas (corn oil). I think it would be cool to be puttin around town and not contributing to all the pollution. If there are any kits available I would be interested. I would appreciate any feedback. Thanks. By the way, is the Hunter a good moped? There are very few here in Hawaii. Tons of Razz's and Elite's but only a hand full of Derbi's. Are there any potential problems I should be aware of? I paid $900 for it and I thought this was a steal. It goes almost 90 kmh (55 mph)

Re: clean burning moped

Chris Robertson /

1) I'm pretty sure you're driving a scooter instead of a moped --we specialize in mopeds.

2) If your scooter is a 2 cycle then you are using too much oil in your gas mix --that's why you are getting so much smoke.

3) Gallon for gallon, a 2 cycle engine pollutes <b>way</b> more than a four cycle engine (especially compared to cars) --you work for an environmental firm, and you probably already know this.

4) Yes, they can be converted to propane --I can't remember the URL off the top of my head, but I have seen instructions on the web before.

5) You can improve your mileage by making sure your machine is in top shape, and driving slower.


Re: clean burning moped

What does you spark plug look like after a good, high speed run. It should be about the color of chocolate milk. If it's black you are either using too rich an oil mixture or running a rich fuel mixture. I suspect the fuel mixture since your mileage is so bad.

Re: clean burning moped

Hi! Your motor needs 300 mi. or so on it to break it in.I agree with Chris and Ken on the diagnosis.This is an oil-injected model,right? So don't mix any into the gas if it is already injecting it,this will make it smoke like a freight train.Synthetic oil in the oil tank will generally yield less smoke,but injectors have been known to over-do it.Check it out.And don't even consider converting to ethanol or methanol.A good 2-cycle doesn't smoke that much,even when it gets pretty old.To waste that much gas something is wrong.I assume you know that to peg the throttle ,especially uphill,is a supreme way to waste gas and pollute the air? So try what these guys said and take it easy on the throttle.Also,make sure that YOUR CHOKE IS NOT STICKING,`cause this will really cost you until sheer vacuum at higher rpms causes it to open.BYE!

Re: clean burning moped

Thanks the help. My moped is actually a moped. In Hawaii it does not require to have insurance or registration because it is under 50cc, therefore it is classified as a moped and you must get a moped license to ride it. Maybe in other states it is considered a scooter but not here (it should be a scooter because of its speed but I still think it's too slow for the freeways). My moped has way more than 300 miles on it - in fact it has almost 4,000 miles. Should I change my oil completely or just add new oil? Do you suggest and brand? As for the propane bit I would definitely like to convert it. Is it expensive? Will it slow my moped down? If so, how much? Is anyone aware of ethanol conversion? If anyone has an URL or general info it is much appreciated. Thanks again.

Re: clean burning moped

Hi! If I owned that bike I'd drain the oil and use the proper recommended synthetic 2-cycle oil.In fact, I'd be tempted to disconnect the auto-injection and mix each tank myself at 40:1 or so.With 4000 mi.,I'd drain the tranny oil and refill with the exact synthetic oil replacement for that oil.Synthetic is unparalled in protecting your gears and bearings and is highly resistant to heat.I've substituted it for many thousands of miles and it's actually caused a reduction in any gear clash noise because of it's resistance to thinning out at high temps..

Re: clean burning moped

I've been meaning to getting around to converting my moped to ethanol or methanol for a while now but still havent done it. Propane seems like too much of a pain to me and costs more to convert. From what i can gather, to convert to ethanol or methanol is rather easy. Alcohol fuels require a greater air to fuel ratio than gasoline (about 8:1 compared to 14.7:1 air:fuel) so you need to change the jet of your carburetor to make it much more rich. Also, 2-stroke oils for gasoline do NOT mix with alcohol, so you have to buy oil that is meant for alcohol (try looking for oils meant for RC cars and airplanes). The only other problem with alcohol is that it can sometimes dissolve rubber or plastic that was made to be resistant to gasoline and not alcohol, and also that alcohol always contains a small percentage of water which can rust a steel gas tank from the inside out.

Re: clean burning moped

Alcohol is the way to go. I am considering picking up another moped just to convert it. I've done it to chainsaws and grass trimmers and it's really not all that involved. The first thing to remember is that all gaskets, hoses, air lines...anything that fuel might touch needs to be replaced with silicone. As for oil, it couldn't be easier. Castor oil is by far the best lubricant and aluminium 2-stroke engine could get. I had and R\C boat with a 25cc Homelite engine I converted. Simple mix. 20% castor oil to 80% alcohol. But it premixed in the hobby shops. Downside is it's about $17 gallon (up here in Toronto at least) so you won't be saving any money. You will find a huge increase in RPM and available horsepower, but a small but noticable decrease in torque. My guess is that you will go through a helluva lot of clutches on alcohol as well as cash.


Re: clean burning moped

When you mean lots of cash how much are we talking here? Maybe I should just concentrate on cleaning up the exhaust coming out of my tailpipe. Any suggestions as to what synthetic oil I should get? A particular brand would be nice. Do you think it would be good enough if I simply waited till I ran out of my current oil and then fill her up with synthetic or just dumpin what I have now and put in the good stuff. Thanks for all the insight and suggestions about conversions but it seems like it could be troublesome as well as very expensive. I thought I could maybe spend $300-400 for the conversion and then maybe about the same or a little more for alternative fuel. I guess I was wrong. I also would hate to jeapordize the reliability of my moped. Oh and one recent problem occured with my moped. I have a problem starting it sometimes. Once in a while it tries to start but then it kind of goes PING SSHSHHH. Okay hard to spell out the sound but it seems like it tries to turn something and then it simply spins without grabbing anything. Very unhealthy. At this point I just kick start it. Is it my starter?

Re: clean burning moped

I have used AMSOIL 100:1 synthetic oil since day 1 in my moped. It's available through distributors or online (which is where I bought it). You can go to the Amsoil website and ask the people there how much you should use in your Derbi and also if you need to do anything special when converting from natural oil to synthetic. You can also read all about the product on the site. Do a search to find the website as I don't know it off-hand.

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