two stroke or 4
July 16, 2009 5:55 PM   Subscribe

I m looking to buy a used scooter, I've looked all over and have not found a definite answer, which is better, 4 stroke or 2?
posted by kanemano to Travel & Transportation (19 answers total) 1 user marked this as a favorite
4-stroke generally means quieter and easier to use, but heavier. 2-stroke means a smaller, lighter motor for a given amount of horsepower, but noisy and you have to mix oil into the gas. Which is better depends on your priorities.
posted by jon1270 at 6:01 PM on July 16, 2009 [1 favorite]

Also, a 4-stroke pollutes much less, if that's one of your priorities.
posted by stopgap at 6:05 PM on July 16, 2009 [2 favorites]

A 4-stroke is also probably going to cost more. You are also going to have to change the oil once in awhile.

If it were me I would get the 4-stroke.
posted by 14580 at 6:07 PM on July 16, 2009

There is no definitive answer. You need to consider quality, noise, vibration, price, pollution, weight, power/speed, maintenance and age when considering what to buy.
posted by captaincrouton at 6:27 PM on July 16, 2009

A 4 stroke is better for the environment, but less power for a given size.
posted by SirStan at 6:51 PM on July 16, 2009

For the same cylinder size, 4 stokes engines are heavier, more complicated (harder to repair), less powerful. 2 strokes engines are stinky, noisy, have fewer mpg, don't last as long, and way way more dirty. They are banished in many Asia cities because of how dirty they are.
posted by gmarceau at 7:01 PM on July 16, 2009

Even if you're unconcerned with pollution, condition is a consideration.
You're buying used: consider the behaviour of the previous owner. Abuse and neglect of a two-stroke is a great deal easier and more serious than a four-stroke, it can be as simple as just not mixing the oil in the fuel a couple of times. That can cause damage that's very hard to repair cheaply.
posted by Fiasco da Gama at 7:17 PM on July 16, 2009

4 strokes are cleaner, more fuel efficient and the engine will last longer, but they are less powerful and more complicated to work on. Some modern 2 stroke scooters do not require you to premix the gas and oil so that isn't necessarily a factor. 2 strokes are faster, but dirtier and worse for the environment. But they are easier to work on, are you planning on working on this yourself? The noise of a 2 stroke isn't necessarily a bad thing either. Since you will be less visible to other vehicles, the noise helps a little. What size engine are you looking at? If you are looking at small engines (around 50 cc) go with a 2 stroke. A 50cc 4 stroke engine is too damn slow and too slow is dangerous.
posted by MaryDellamorte at 7:20 PM on July 16, 2009

I think you are omitting a big piece of info here. What do you want out of your scooter?

Do you want it to be a little 2 stroke putting away, getting amazing fuel economy, or do you want a 250cc 4 stroke enabling you to hit 80mph on the highway in comfort?
posted by Frasermoo at 8:20 PM on July 16, 2009

Yeah, I had a Yamaha Zuma (2-stroke) because it was the most solid scooter under 50cc. In Wisconsin, that means you can still park it just about anywhere; anything more, and you'll have to get a motorcycle license.

Because I hadn't ridden a scooter before, I was apprehensive about the Zuma's power compared to the slightly smaller 4-strokes like the Honda Metropolitan and the Yamaha Vino. The salesperson convinced me that I would get used to the additional power of the 2-stroke, but if I got a 4-stroke and got used to it, I wouldn't have those power reserves. But it wasn't so much the power as the fact that it made for a smoother ride overall.

I think the Zuma was discontinued as a new model, but I'd recommend it highly if you can find one. Should be pretty easy to get service since Yamaha is such a prominent company, and the wider tires/good shocks/slightly higher seat make the Zuma very comfortable and smooth.
posted by Madamina at 8:34 PM on July 16, 2009

2-stroke engine exhaust smells awful. If I were you I wouldn't want that getting on my clothes and hair.
posted by oceanmorning at 10:21 PM on July 16, 2009 [1 favorite]

I've owned both.

Here's what you have to worry about with a four-stroke: when did I change the oil last?

Here's what you have to worry about with a two-stroke: when did I put two stroke oil in last (in automix models) or how much oil do I need to put in relative to the gas I just got to get the mix right. And shake the scooter to mix the oil. Am I giving it enough gas going downhill? Is my engine about to seize? Is my jetting right? Do I have any two stroke oil with me?

Two-stroke scooters are wonderful and hairy creatures. You're not going to go much more than 50mph on a 150cc Vespa or Lambretta. It's incredibly easy to seize a two-stroke engine. You'll likely need to be your own mechanic unless you happen to live near one of the few places with a Vespa/Lammy shop. I see you're in Hawaii... all the Vespa shops I know of are on the mainland, so add that shipping expense to your inevitable parts orders.

Four-strokes, on the other hand, are usually Honda or Yamahas. And finding a Honda or Yamaha dealer/shop to work on your ride is a lot easier.

If you want to ride and not think about all that other stuff, get a four-stroke. If you want to be part of a colorful subculture, get a two-stroke.
posted by jdfan at 4:08 AM on July 17, 2009

And Ipone 2 stroke oil makes your exhaust smell like strawberries. Any modern 2 stroke oil won't stink up the place like old 2T oil did.

And don't buy a "restored" Vespa off ebay.
posted by jdfan at 4:15 AM on July 17, 2009 [1 favorite]

jdfan is exaggerating a bit. I have a 2-stroke, 50cc Piaggio with over 10,000 miles on it. It is de-ristricted and goes about 45MPH max. Other than changing the spark plug, brakes and a flat tire I have never had a problem.
2-stokes in general will give you twice the power as 4 strokes (all other things being equal) Why? Every other stroke is a power stroke. With a 4-stroke every 4th stroke is a power stroke. 2-strokes have more torque at start-up than 4-strokes, but you may be able to modify the CVT transmission rollers to change the power curve.
Most modern 2-strokes use oil injection. The oil reservoir is rather large, and only needs to be refilled about every 5 or 6 time you fill up the gas. (IMHO I think they burn far less oil than pre-mix types) If there's any oil at all it is nearly impossible to seize a 2-stroke, so don't worry too much. Plus you don't get that wicked cool 2-stroke buzz with a 4-stroke.
posted by Gungho at 5:13 AM on July 17, 2009

I have a 2-stroke Yamaha, and it's great. Well, it does have some stinky exhaust, especially if I haven't driven it for a couple of weeks, but I just add oil whenever the oil light comes on, no pre-mixing or anything.

Top speed is pretty lame, though. Only about 30 mph (mine was used when I got it, and has seen a lot of action). BUT, the acceleration cannot be beat. At a red light when I hit the gas --boom--I'm outta there before the other drivers can barely react. Four-stroke engines generally have better top speeds, but slower acceleration.
posted by zardoz at 6:01 AM on July 17, 2009

As a cyclist in a city that used to have lots of 2-stroke scooters (Dublin), I dislike them a lot. I found them extremely noisy, with a noticeably bad smell, in addition to being polluting. Teenagers who were under a certain age had to drive a 2-stroke before being allowed to move up to a more powerful scooter/moterbike. This also meant that 2-stroke drivers were frequently much worse than other motorized two-wheelers.

4-strokes on the other hand, can be noisy, but generally I found them much more tolerable.
posted by a womble is an active kind of sloth at 7:51 AM on July 17, 2009

I would say it also depends on how much of a DIYer you are, and how accessible technical information is about your scooter.

If you are looking at vespas, ModernVespa is a great resource for both modern and vintage scoots.
posted by o0dano0o at 8:34 AM on July 17, 2009

I just got back from my first trip with my new (used) 4-stroke. As someone with no clue about motors and so on I say grab a 4-stroke. Speaking of which, off down to fuel her now. Plain old petrol from the pump.
posted by Iteki at 9:01 AM on July 17, 2009

I don't understand all of this "ooh, 2-strokes are so complicated" stuff. On the Zuma, there's a little screw-on cap under the seat, and there's an oil gauge on the dash. When the oil gauge says you're low, you pour more oil in. There's even a little lip so you can tell when to stop. And that's it, at least until... oh, next month or so. I kept a bottle of oil in a plastic bag in the compartment under my seat so I could do it when I gassed up.

Really complicated :P
posted by Madamina at 10:58 PM on July 19, 2009

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