2 stroke vs 4 stroke

[Tank]

Asking this in General as opposed to scooters to get a wider audience.

Im looking at getting the missus a scooter.

Options engine wise are a 110 2 stroke (the PGO) or a 125 4 stroke (Suki and others).

Now our main problem is that we live on a BIG ASS hill - so the scoots got to have a wee amount of guts - a 50 wont make it (test rode and it was doing a dangerous 15km on the hill flat out).

I know nothing about 2 strokes - will this have more power or less? (I know Big Dog has the PGO 110 2 stroke and he seems to get along OK).

Any help will be awesome.

Tank

[Badjelly]

I know nothing about 2 strokes - will this have more power or less?

Even a notorious 2-stroke hater such as myself has to admit 2-strokes generally have more power for a given capacity (on account of the fact they fire once per revolution rather than once per 2 revolutions). Why do you think they let 250 4-strokes race against 125 2-strokes in MX?

[Devil]

Here's the theoretical side of it.
Using the same capacity, a two stroke produces a similar amount of power per engine cycle (two piston strokes, or four piston strokes). It just does it twice as often (every two strokes instead of four) so, a two stroke generally on paper has almost twice as much power as a similar capacity four stroke.

I'm looking into a 125 4 stroke scooter as well, will have to test it though.

[MisterD]

Also worth bearing in mind that 4-strokes are generally higher compression and therefore give you a bit more torque.

[Flatcap]

Two strokes smell better

[enigma51]

Two strokes are smaller and more compact engines so they tend to be lighter.

4 stroke is easier to maintain as you just fill it up where a 2 stroke you actualy have to check the oil every fill up.

[Tank]

I'm looking into a 125 4 stroke scooter as well, will have to test it though.

Can I ask what ones you are looking at? - Im currently leaning to the AN125 Suki - at least I know I will get parts, and the dealer has been awesome to date and Id like to give him my business if reasonable.

[scracha]

2 strokes belong on chainsaws and race tracks. Too much of a PITA for regular road use IMHO unless you actually like reboring engines, fannying about with 2 stroke pumps/premix and changing spark plugs.

[Devil]

Can I ask what ones you are looking at? - Im currently leaning to the AN125 Suki - at least I know I will get parts, and the dealer has been awesome to date and Id like to give him my business if reasonable.

The AN125 and the UZ125.
Is it the AN that comes with alarm and 12V socket?
Would buy from Holeshot. I'd got the 4 stroke way just for maintenance reasons.
Will go speak to Rob in the service dept first because I know they've had issues with some of the 125's, but I think they have been discontinued (the particular problem model).

[EJK]

The AN125 and the UZ125.
Is it the AN that comes with alarm and 12V socket?
Would buy from Holeshot. I'd got the 4 stroke way just for maintenance reasons.
Will go speak to Rob in the service dept first because I know they've had issues with some of the 125's, but I think they have been discontinued (the particular problem model).

the UZ125 has the alarm and the 12v socket.

I heard (and test rode) a UZ125 and...... it's a good scooter. Maybe the best* in the range. It's fuel injected too.

Well I've got two PMs about 100cc 2 Stroke scooter, I'll forward it to you in a sec :niceone:

best*: light, quick, and I presume reliable

P.S. How about Italian Piaggio Fly 125? It's in the same price range

[C_A]

2 strokes belong on chainsaws and race tracks. Too much of a PITA for regular road use IMHO unless you actually like reboring engines, fannying about with 2 stroke pumps/premix and changing spark plugs.


they're hardly any worse than any engine if you treat them right. scooters are hardly going to foul plugs if you use decent oil and dont ride everywhere at idle.
plus 4 strokes have all that messy valve gear which you jsut know will fail given the revs scooters pull (who doesn't ride them at the absolute fastest they'll go on the flat, then even faster down hill?)

two stroke all the way.

[quallman1234]

With reference to scooters.

Mainteance will be the same comparing the two scooters.

Fuel consumption will be very similar (110cc 2 stroke vs 125cc 4 stroke), however you will have to add a 1L of oil approxmentally 800 - 1000km (Scooter 2T oil is cheap so not that bad however racing 2T oil used in high reving scooters are not cheap 25 $ + a litre)

The 2 stroke definitely will be quicker.
And none of this bullshit changing sparkplugs crap every now and then, all you need is 2 stroke oil and petrol and she be fine! (maybe an 8$ spark plug once every 2 years might be good tho).

Lots of people think 2 strokes are less reliable than 4 strokes. Yeah correct if we were living in 1960 - 1980's . The fact of the matter is they are just as reliable if not more so these days.

4 Stroke riders just can't hack that we make more power per cc than them :clap:

[F5 Dave]

Also worth bearing in mind that 4-strokes are generally higher compression and therefore give you a bit more torque.
Wrong & also incorrect. Their BMEP may be higher but it has little to do with the compression ratio. Dynamically 2 strokes can have a fairly high compression ratio, their static measurement isn't really relevant.

Torque at the rear wheel the higher horsepower unit will have more, but I suspect you are misusing the word talking about power spread. Trials bikes all used to be 2 strokes as they could provide a better spread of power than a 4 stroke, emissions laws changing that. Depends on how any engine is designed/tuned.


2 strokes belong on chainsaws and race tracks. Too much of a PITA for regular road use IMHO unless you actually like reboring engines, fannying about with 2 stroke pumps/premix and changing spark plugs.

Valves belong in toilets, you're living in the dark past. Even 60s Vespas aren't as black as you paint it, modern Jap stuff is as reliable as anything else. Chinese stuff, good luck you'll need it. European, hmm. . .

On the other side of the equation you should also ask yourself how your wife will cope with small scooter wheels over wet manhole covers in the dark. They have their place, but it really depends on what your local roads are like. I would consider a large wheel bike for around my local suburb hilly roads.

Don't skimp on decent gear with armour, she will need to understand she has to wear heavy boots & stuff even for short trips.

How long will it take to pay back the initial investment considering she may not like it & may take the car when it is raining?

[MisterD]

Wrong & also incorrect. Their BMEP may be higher but it has little to do with the compression ratio. Dynamically 2 strokes can have a fairly high compression ratio, their static measurement isn't really relevant.

Torque at the rear wheel the higher horsepower unit will have more, but I suspect you are misusing the word talking about power spread. Trials bikes all used to be 2 strokes as they could provide a better spread of power than a 4 stroke, emissions laws changing that. Depends on how any engine is designed/tuned.


No, I'm not talking about power spread. Put it this way, I have two scooters with similar 187 ish cc rating...the 4s will 'engine brake' far more than the 2s, and that 2-stroke is set up for torque and rideability rather than outright power (no chamber).

[F5 Dave]

. . . . Put it this way, . . .

Why put it that way? it doesn't illustrate anything more than your 4 stroke has more engine braking. My point was that compression ratio isn't the relevant factor.
Comparing 2 engines of similar size is all very interesting but does not a study on the engine genre make. Lets say we use a Italjet Dragstar or whatever they are for the 180 version. That will create more torque than any 4 stroke scooter of similar size I bet, just in the way a peaky R6 can create a lot more torque than a 1340 Harley. Just the word Torque is highly misused.

[Chickenlegs]

2 strokes belong on chainsaws and race tracks. Too much of a PITA for regular road use IMHO unless you actually like reboring engines, fannying about with 2 stroke pumps/premix and changing spark plugs.

Absolute bullshit!

Have you ever had any road 2-strokes or are you jumping on the bandwagon...

[speedpro]

I can't comment on the Suzuki scooters but I did work in a Yamaha shop and had the opportunity to ride both the Yamaha Beewee(100cc 2-stroke) and the Yamaha Cygnus(125cc 4-stroke). They had fairly similar outright performance - acceleration and top speed. However the Cygnus was a far more refined scooter. It moved off and got along without too many sensations other than the wind going past. The Beewee on the other hand was a little busier, nothing to worry about but just seemed to be more going on than the Cygnus. In comparison to the Chinese scooters there wasn't any, comparison that is. The price of the Cygnus is getting up there a bit but it's a bloody good scooter. The Beewee at least has a low oil warning light so there is no requirement to check. You can put a couple of tanks through once it comes on.

Keep a good eye on the wheel bearings if you go Suzuki. Both scooters and GN250s must have the crappiest bearings the Chinese make.

You have to try the brakes out on those things as well. I guarantee I could outbrake anything in the shop with anybody else riding it. you grab two handfulls and it was like running into a brick wall.

[davereid]

Choose the two-stroke.

It will use more fuel than the four stroke, but as you are running on an oily rag anyway it is irrelevant.

It will produce more power, and be a more rewarding ride.

It WONT cost you more to run.

Yep, you have to feed it two-stroke oil.

But it only eats at at about 100:1, so every $200 of gas you need $14 oil, or $17 if you buy synthetic. (Which is a great idea.)

That 100 litres of gas may take you 2000 - 4000 km depending on what you buy and how you ride it.

So at the same time you need a new bottle of two-stroke, you 4-stroke riding pal, needs oil too. But more than you need. Maybe he needs a filter too. He needs the valve clearances reset. Do it yourself, or, for $85/hr you can get it done at the shop.

Both bikes will need airfilters cleaned and re-oiled, and general nuts-and-bolts.

Question 2...

Do you REALLY need a 125 ?

Good moped reg 50cc two-strokes will kill any hill.
Trust my big-arse ! 95kg of tester here and 40,000 km of testing.

A 50cc moped reg bike...
- needs no WOF
- costs $67 a year to register
- can be ridden on ANY licence
- Can legally only do 50km/hr
- Will climb any hill as long as its a GOOD BRAND two stroke

Your 125 cc bike..
- will cost $200 + for rego
- will need WOFs @ $40
- needs a Motorcycle licence
- BUT.. is capable of 80-100kmh, and motorway use, very good feature if you need to use a motorway

IMHO, a 2-stroke, quality moped, does 90% of commuting.. disadvantaged only if you need to go on the motorway.

For what its worth, I do 14km a day on SH1 on a moped. It takes me 15 minutes. At the legal speed limit, it would take me 10. Unless the lights were red.

[WRT]

Also worth bearing in mind that 4-strokes are generally higher compression and therefore give you a bit more torque.

You sure about that? I don't know scooters, but I know MX and here's the closest 2 stroke vs 4 stroke comparison I can make:

http://www.motorbikes.be/en/compare/4570/4568/

05' CR 250 R vs 05 CRF 450 R. Both Honda, both MX. Despite the four stroke having almost double the capacity, the two stroke makes more power, AND MORE TORQUE, plus it weighs less. The four stroke does have a higher compression ratio, and it does have more engine braking, but it doesn't have more torque.

In fact, if you compare the same size CC rating:

http://www.motorbikes.be/en/compare/4570/4608/

The 2 stroke more than double the torque, and nearly double the HP. And lets face it, Honda has given the four stroke significantly more development time and money.

Plus I know which one is easier to start, easier to work on, and which one costs less for a service. Four strokes have two advantages, sound and fuel economy. Everything else goes the two strokes way.

Now scooters might be a different kettle of fish, so perhaps someone who knows scooter models might like to pick out a similar comparison?

[FLYMO]

yeah 2 stroke the way to go
never likeed the sound of a 4 stroke scooter
just doesnt sound right

[Coyote]

And lets face it, Honda has given the four stroke significantly more development time and money.

Plus I know which one is easier to start, easier to work on, and which one costs less for a service. Four strokes have two advantages, sound and fuel economy. Everything else goes the two strokes way.
That's because Mr Honda never liked 2 strokes.

2 strokes have the sound advantage :p

[scracha]

Plus I know which one is easier to start

?? The starter button always works on my 4 strokes.



easier to work on, and which one costs less for a service.

Doesn't really count for much when they require a hell of a lot more servicing.


Absolute bullshit!

Have you ever had any road 2-strokes or are you jumping on the bandwagon...

Suzuki GP100
Suzuki GP1somehting (ok, a GP125 but it was bored out)
Suzuki GP125
Suzuki X5
Some piaggio 50cc scooter thingie.

There is basically zero (nil, nada, eff all) maintenance on a modern 4 stroke so your comparisons are a joke. I don't see many 2 strokes running about on their original rings after 100,000 kms? I don't know any 2 stroke owners that just get their bike serviced once a year. Hell, one of my four strokes never missed a beat for 3 years (daily commuting use and 150km each way 140kmph (UK roads) trip to girlfriends at weekends) and only had one oil change during the whole time. The 2 strokes were a complete hassle. Mental fun but just nothing but hassle.

Aside from a track bike I'd never own one again. If you're quite handy and enjoy working on bikes then yep, 2 strokes are fun and easy to work on. If you need a bike to get you from A to B and aren't particularly interested in maintenance then a 2 stroke is not for you.

[Tank]

Thanks all for your help.

Got the Missus a AN125 (4 stroke) from my friends at Holeshot.

They have little margin in them, but they threw in helmet and gloves for her.

[Timber020]

?? The starter button always works on my 4 strokes.


Doesn't really count for much when they require a hell of a lot more servicing.



Suzuki GP100
Suzuki GP1somehting (ok, a GP125 but it was bored out)
Suzuki GP125
Suzuki X5
Some piaggio 50cc scooter thingie.

There is basically zero (nil, nada, eff all) maintenance on a modern 4 stroke so your comparisons are a joke. I don't see many 2 strokes running about on their original rings after 100,000 kms? I don't know any 2 stroke owners that just get their bike serviced once a year. Hell, one of my four strokes never missed a beat for 3 years (daily commuting use and 150km each way 140kmph (UK roads) trip to girlfriends at weekends) and only had one oil change during the whole time. The 2 strokes were a complete hassle. Mental fun but just nothing but hassle.

Aside from a track bike I'd never own one again. If you're quite handy and enjoy working on bikes then yep, 2 strokes are fun and easy to work on. If you need a bike to get you from A to B and aren't particularly interested in maintenance then a 2 stroke is not for you.

Hell of a lot more servicing? The suzuki GP and X series were gone by the early 80s werent they? Thats a quarter century ago. Before cell phones, no internet, Carless days, John lennon getting shot, cortinas and capris still being made.......thats old stuff. Its like my father in law complaining about the build quality of toyotas because the one he brought in 1978 rusted in the doors. As for the Piaggo, arent they italian?

2 strokes have got alot better since then, they still put out more power and weigh less but the maintainance schedules have massively been reduce and there longevity increased. The main reason more of them arent about are due to EPA requirements strangling them. Your still getting more bike with a comparitable 2 stroke, and on scooters and hills, hp counts in traffic.

The 4 strokes do require less serviceing, but not a hell of a lot less. And when it is time for them to be done it tends to be more expensive anyhow. Ask the guys that went from CR250s to CRF's how there servicing costs have gone. There has to be good reason why so many scooters are still 2 strokes.

[Chickenlegs]

??

Suzuki GP100
Suzuki GP1somehting (ok, a GP125 but it was bored out)
Suzuki GP125
Suzuki X5
Some piaggio 50cc scooter thingie.

There's your problem... All/mostly Slowzukis....

Must be why you came to NZ then... Were part of the sheep brigade then already...

[quallman1234]

Wooooo now we have a real 2 stroke vs 4 stroke thread brewing!

He has a point you haven't had a modern 2 stroke.

Air cooled 2 strokes espically.

Have you had bad expirence with ol 2 smokers Mr Honda ehhhh sorry i mean scracha

[scracha]

A 50cc moped reg bike...
- needs no WOF
- costs $67 a year to register
- can be ridden on ANY licence

Who says the laws in this country are stupid? Any license? Now WOF? I mean, FFS my wee bike trailer needs a wof but they let untrained idiots out on deathtrap mopeds?


Wooooo now we have a real 2 stroke vs 4 stroke thread brewing!




He has a point you haven't had a modern 2 stroke.

Most of my mates had them. One in particular seemed to have to take the bus more often than not upon purchasing a 3 year old RGV250.



Have you had bad expirence with ol 2 smokers Mr Honda ehhhh sorry i mean scracha

Mr Honda? It's only my second one you twat:Pokey: I've had Suzuki's, umpteen Yamahas (love em), umpteen Kawasaki's and also an Eyetye bike.

And comparing high performance screaming 250cc 4 stroke MX bikes that are trying to make the same power as a 250 2 stroke isn't very valid. Yeah, 2 strokes have more bang per cc and are lighter but I never disputed that.

Modern 2 strokes? What modern 2 strokes? I haven't seen the 2 stroke equivalent of a CBR600 in my local bike shop lately.

2 strokes are for fags
(but hey, if anyone wants to lend me one at the track I'll suck cock*)














*cock must have no feathers left, be throughly cooked and preferably dipped in barbecue sauce.

[WRT]

Most of my mates had them. One in particular seemed to have to take the bus more often than not upon purchasing a 3 year old RGV250.
[snip]
And comparing high performance screaming 250cc 4 stroke MX bikes that are trying to make the same power as a 250 2 stroke isn't very valid. Yeah, 2 strokes have more bang per cc and are lighter but I never disputed that.


I did mention that I only know MX, not scooters, so you are right - I was comparing "high performance screaming" MX bikes. However, you're using an RGV250 as an example, so I feel somewhat justified.

Despite the somewhat ambiguous thread title, the OP was talking scooters so my question still stands - does anyone know of a similar comparison between 2/ and 4/ scooters? Same manufacturer, similar output, same target market, just a different type of engine? Would help if the maintenance schedule was included as well.

Edit: oh and the "easier to start" comment was referring to the CR/CRF range, dunno if any scooters these days are still kick start, but a 2/ is much easier to kick over than a 4/ - comes back to your point about the higher compression.

[C_A]

jesus chirst. I roll on a 100k old rg250. 3 kick max to start. reliable as an old watch
old pasolla. single kick to start. has been aorund the clock a few times, and it goes fine.

two strokes are sweet as. all the neigh sayers are pretty moronic to not realise that mopeds have been predominantly 2 stroke since their inception. and what city dweller moped owner does ANY maintenance on them, or has trouble with them? none

[Chickenlegs]

Who says the laws in this country are stupid? Any license? Now WOF? I mean, FFS my wee bike trailer needs a wof but they let untrained idiots out on deathtrap mopeds?





2 strokes are for fags


I agree with the first post....

I never knew cigarettes could ride motorbikes...

[Chickenlegs]

In all seriousness....

I think a lot of 2-strokes have a bad rep because a LOT of them have been played with.

A standard RD, RG or RGV, TZR, NSR, etc. will happily do many thousands of k's. The problem is, owners usually tend screw with them and by the time it's had a few owners, it's pretty screwed...

They are more susceptible to climatic conditions and jetting, so can easily be seized.... Standard though, they'll live a long life...

EG: I had a mate who had a RZ500 (RD500 for Scracha), and it was reliable as... Mate decided to give the bike a birthday but rebore it and do a bit of porting while at it... It was never as good afterwards...

[scracha]

EG: I had a mate who had a RZ500 (RD500 for Scracha), and it was reliable as... Mate decided to give the bike a birthday but rebore it and do a bit of porting while at it... It was never as good afterwards...

Oh there's nothing like the sound of a TZR250 getting it's nads screwed out of it round a race track.

Ducati 2 strokes....the ultimate in reliability :wari:
http://www.bevelheaven.com/brochure-index-2stroke.htm

[quallman1234]

Wow calm down buddy, i just think your be a little short sighted. Of course it come's down to your own personal expirence with such machine's personally i have had much worse problems with 4 strokes than my 2 smokers, but that could be to do with i look after them (sometimes track bikes don't count right ;)).I seriously can go crazy sometimes whilst on a 2 smoker, being in that meaty powerband is a kick for me.
Gotta love hitting power band and feeling like a GP rider :).


Loving the ducati 2 smokers :).

[sosman]

Get the two stroke! & you dont need two smoke oil every time you put gas in.
I had a suzuki zz50 & put oil in, round every 5 or 6 gas fills,also i could do the piston & rings my self! cause i wouldn't have the foggiest about 4strokes

[jade]

Modern 2 strokes are sweet as..
Ive ridden my bike every day now as my only form of transport for 20 months now... still kicks over first pop dead cold, has never once skipped a beat and I thrash the bejesus out of it every day
I doubt anyone in this country thrashes their bike as bad as me any my mate do... they are perfectly reliable
Ive ridden a few other bikes on the road (like brand new sportsbikes) and whilst they are ultimately faster etc, they are not as fun - period
throw 20 stoppies a day and off the throttle wheelies with enough power to flip into the equation and its the most fun you can have with your clothes on, ill get a big bike, but im keeping my current bike forever

[TLDV8]

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