Author Topic: 2 stroke or 4 stroke  (Read 5556 times)

Dale4

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2 stroke or 4 stroke
« on: January 08, 2011, 10:41:26 PM »
I have an agility 50 and derestricted (cdi and boss) it does about 35-38mph. I need to do about 42-45 mph,would a 2 stroke 50cc scooter with the same derestrictions go faster than my 4 stroke agility 50? I'm not looking to get a scooter higher than 50cc,thats why I'm asking  TY  Dale

juice

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Re: 2 stroke or 4 stroke
« Reply #1 on: January 08, 2011, 10:52:46 PM »
I have a derestricted people 50 and a genuine buddy 50 . Both of them are stock and will do 45 mph + .

ts1

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Re: 2 stroke or 4 stroke
« Reply #2 on: January 08, 2011, 11:16:35 PM »
Only derestriction isn't always enough.
The Agility is available with a 2 stroke engine too. Then 2.8kW, which (imho) is almost not enough.
But there are 2 stroke scooters which have enough power. The Aprilia SR50R with 4.2kW is homogolated with 78 kph (48 mph) in Switzerland (for driving license A1).
And you need the adequate transmission length. (Unrestricted 2 stroke engine usually rev higher than standard too, so that's not a common problem.)

Disclaimer:
I don't speek about speedometer indicating, I mean official top speed.

juice

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Re: 2 stroke or 4 stroke
« Reply #3 on: January 09, 2011, 02:12:13 AM »
I should have explained I have seen both speedometers go past 50 mph , so im guessing 45 ?

scootergrisen

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Re: 2 stroke or 4 stroke
« Reply #4 on: January 09, 2011, 02:14:49 AM »
I think 2 stroke will accelerate more quickly but i think the top speed is the same.
There is proberly a resitricing in the air box and then charge the carburetor jet from 80 to 85. Then you will proberly meet your goal for speed.
But you need to do both there restrictions at the same time. If you only do 1 of them the scooter will just run bad.
Im not shure about the air box and cant seem to find any pictures of it but just remoce the air box cover and see if there is a "funnel" like this one on my Kymco Super 8 :

juice

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Re: 2 stroke or 4 stroke
« Reply #5 on: January 09, 2011, 04:19:43 AM »
I have also owned a honda metropolitan and 2 yamaha vino 50 classic 4 strokes . The 2 strokes are faster in every way . I have not adjusted the carburator jetting or altered the air cleaners and I am running the stock exhaust . The 4 strokes are quieter and get better gas milage . They are also supposed to be more reliable , but they are just not as fast in their stock form . I have logged close to 10,000 mi. on 50cc scoots and these are my observations .

axy

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Re: 2 stroke or 4 stroke
« Reply #6 on: January 09, 2011, 01:00:15 PM »
I have an agility 50 and derestricted (cdi and boss) it does about 35-38mph. I need to do about 42-45 mph,would a 2 stroke 50cc scooter with the same derestrictions go faster than my 4 stroke agility 50? I'm not looking to get a scooter higher than 50cc,thats why I'm asking  TY  Dale

YES.

It has nothing to do with 2 or 4 strokes, it has everything to do with power output.
50 cc 2 strokewill have almost twice the power of 50 cc 4 stroke.
« Last Edit: January 09, 2011, 09:23:25 PM by axy »
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Kymco People GT300i 2017 ABS Euro4
Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

ts1

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Re: 2 stroke or 4 stroke
« Reply #7 on: January 09, 2011, 02:06:47 PM »
50 cc 4 strokewill have almost twice the power of 50 cc 2 stroke.
You mean "half".

In engineering theory the 2 stroke has about 60% more power (not 100% because some part of the pistons travel is used for gas exchange).
But with modern emission limits the 2 stroke can't reach 60% and may even became less powerful than the 4 stroke. In car engine technology with Euro 6 on the horizon we might never see a 2 stroke again.

axy

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Re: 2 stroke or 4 stroke
« Reply #8 on: January 09, 2011, 09:27:51 PM »
You mean "half".

In engineering theory the 2 stroke has about 60% more power (not 100% because some part of the pistons travel is used for gas exchange).
But with modern emission limits the 2 stroke can't reach 60% and may even became less powerful than the 4 stroke. In car engine technology with Euro 6 on the horizon we might never see a 2 stroke again.

Corrected.

Btw. a few years ago the breaking news all over the place was that the future is in very sophisticated 2-stroke turbo engines for cars and motorcycles?!?
Now they produce turbo charged gasoline BMWs that have kerb weight of 1400+ kg, 200 hp and consume 9 l of gasoline on the average, the same as my car that weighs 1150 kg, has 1400 cc naturally aspirated engine with 110 hp. If somebody told me that 15 years ago when turbo charged cars with 150-200 hp consumed 15-18 l/100 km, I would say that kind of engineering will never exist.

Of course it is not possible (or economical) to make clean 2-stroke engines for cars and motorcycles.
Sometimes we from Europe and USA are very westerncentric-eurocentric - there are a lot of places in the world that do not adhere to Euro emission norms and never will. :) :) :)
« Last Edit: January 10, 2011, 09:57:18 AM by axy »
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Kymco People GT300i 2017 ABS Euro4
Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

blue

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Re: 2 stroke or 4 stroke
« Reply #9 on: January 09, 2011, 09:54:52 PM »
the honda rucks has a water cooled engine that would be sweet in a kymco.

axy

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Re: 2 stroke or 4 stroke
« Reply #10 on: January 10, 2011, 09:59:07 AM »
the honda rucks has a water cooled engine that would be sweet in a kymco.

This is another scoot very popular in USA and completely unknown in Europe.
Btw. I like this one:

http://image.superstreetonline.com/f/9782115/130_0804_03_z+honda_ruckus+military_camo_design.jpg
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Kymco People GT300i 2017 ABS Euro4
Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

ts1

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Re: 2 stroke or 4 stroke
« Reply #11 on: January 10, 2011, 10:17:47 AM »
Europe knows the Ruckus as Zoomer.

Kymco will introduce a 50cc 4 stroke fuel injected soon. But imho still AC, because this small displacements don't need LC.
« Last Edit: January 10, 2011, 10:21:30 AM by ts1 »

axy

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Re: 2 stroke or 4 stroke
« Reply #12 on: January 10, 2011, 02:53:07 PM »
Europe knows the Ruckus as Zoomer.

Kymco will introduce a 50cc 4 stroke fuel injected soon. But imho still AC, because this small displacements don't need LC.

It is interesting that I have experienced engine overheating only with LC 50 cc, never with AC!
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Kymco People GT300i 2017 ABS Euro4
Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

axy

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Re: 2 stroke or 4 stroke
« Reply #13 on: January 10, 2011, 02:55:13 PM »
Europe knows the Ruckus as Zoomer.

Kymco will introduce a 50cc 4 stroke fuel injected soon. But imho still AC, because this small displacements don't need LC.

Btw. Ruckus (Zoomer) 50 costs here 3900 US$!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You could almost buy two A125 for that kind of money!

No wonder they sold none (at least in my country).
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Kymco People GT300i 2017 ABS Euro4
Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

oswaldters

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Re: 2 stroke or 4 stroke
« Reply #14 on: January 11, 2011, 02:22:54 AM »
Kymco will introduce a 50cc 4 stroke fuel injected soon.

I've been waiting for that for 2 years!

Would be really nice to just start and go on these really cold mornings.

Any details on what model it will be?

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