2 vs. 4 Stroke...

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jmr3394

New Member
Apr 5, 2010
79
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U.S.A.
Money not an object. Why would someone pick a 4 stroke over a 2 stroke? and vice versa? Don't 2 strokes make more power?
 

nolan_speed

New Member
May 31, 2010
30
0
0
Seattle, WA
4 strokes generally cost more, last longer, are quieter, use less gas, pollute less, don't require oil mixed in the gas, make slightly less power per displacement, Have a broader torque curve, and foul plugs less.

I'd generally say that a 4 stroke is better in most ways. The exception is in maximum power, where a 2 stroke usually is a little bit better, weight, and cost.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
1,797
113
Los Angeles, CA.
There have been many threads on this subject... :rolleyes:

I totally disagree with the above statement! (except for the fact that they cost more!)
2-stokes don't foul the plugs (if you mix your gas right), they last just as long (if you take proper care of them), they are just as quiet (they both have the exact same mufflers!!), there's zero smoke if you use synthetic oil mixed @ 100:1, they cost less, look better & fit in to more frames, they have far less parts to break, they are much faster!! (there's never been a 4-smoker that could keep up with us on our rides!!), more high performance parts for them & they get 90MPG even after totally hot rodding them!!!

4-strokes are heavier, co$t three times more, they are slower & have way less hill climbing power, they have ten times more parts that can break, require super wide pedal cranks to clear the engine, they have centrifugal clutches (that blow), they're ugly, (they look like you put a lawn mower engine on your bike), they only have pull starts (which break), & no one makes high performance parts for them!



2-strokes rule!!! ;)
 
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Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
There have been many threads on this subject... :rolleyes:

I totally disagree with the above statement! (except for the fact that they cost more!)
2-stokes don't foul the plugs (if you mix your gas right), they last just as long (if you take proper care of them), they are just as quiet (they both have the exact same mufflers!!), there's zero smoke if you use synthetic oil mixed @ 100:1, they cost less, look better & fit in to more frames, they have far less parts to break, they are much faster!! (there's never been a 4-smoker that could keep up with us on our rides!!), more high performance parts for them & they get 90MPG even after totally hot rodding them!!!

4-strokes are heavier, co$t three times more, they are slower & have way less hill climbing power, they have ten times more parts that can break, require super wide pedal cranks to clear the engine, they have centrifugal clutches (that blow), they're ugly, (they look like you put a lawn mower engine on your bike), they only have pull starts (which break), & no one makes high performance parts for them!



2-strokes rule!!! ;)[/QUOTE

Thanks for saving me the typing.
 

azbill

Active Member
May 18, 2008
3,358
5
38
63
Fountain Hills, Arizona
that being said,,,
I love the smooth, vibration free feel of my 4stroke :)
bolts don't vibrate loose... or nuts either (mine) !!! laff

other than oil changes, mine is virtually maintenance free ;)
 

Elmo

New Member
Sep 3, 2009
748
4
0
Mississippi
I havent seen any posts about 4 strokes turning into a grenade within the first 200 miles. Havent seen any posts about trying to get the 4 strokes running after building the kit bike. The two strokes are initially cheaper but after replacing the engine three or for times?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
I have never grenaded and engine, nor have I had to replace an engine or major component....or even a small component.
 

metalliatic

New Member
Mar 14, 2010
96
0
0
Louisville Ky
i had a in frame 4 stroke with a centrifical clutch. i hatted it. no power! just as loud. cost more. heavier. bulky. even with a widder crank the peddles hit the motor. mine had just as much vibration. with half the power. top speed was about 20mph instead of 40mph. i can peddle faster then my four storke would go. forget about hills. mine was a chinese honda clone 49cc just like the one on the broped site. changing the oil ment you got oil all over the bike and you unless you remove the engine from the bike. 2 stroke forever!!
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
1,797
113
Los Angeles, CA.
I havent seen any posts about 4 strokes turning into a grenade within the first 200 miles. Havent seen any posts about trying to get the 4 strokes running after building the kit bike. The two strokes are initially cheaper but after replacing the engine three or for times?
The reason that you hear about all these problems with 2-strokes is because there are 1000s of 2-strokes to every one 4-stroke being sold!!! (& just as many inexperienced builders trying to work on them!) :rolleyes:

I personally have only ever had two engines go bad... One of them had a main bearing installed backward from the factory, & the other died from 2.5 years of fast riding & abuse!! ;)
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
I don't have a good basis for comparison. My only 4 stroke is on a trike and my 2 strokers are on bicycles. I can't compare speed and power but I will say this about the 2 strokes.
I don't have to adjust valves.
I don't have to change oil.
The clutches never slip
It takes me all of about 3 minutes to mix up a batch of fuel.
Easy starting, nice idle and they sound like the Harley Hummer I had as a kid.
And...They look way cooler as an in-frame.
Just my opinions.
Tom
 

Tim_B_172

New Member
Aug 26, 2009
251
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40
Saint Joseph, MO
I prefer the 2 strokes for all of the above reason, but especially the power thing. For what they weigh, they put out plenty of power. Parts availability and the fact that many parts are interchangeable from one manufacturer to the other. Face it, the Chinese factories are probably all working from the same set of blueprints anyway. And then there's the looks, I don't like the way lawn mowers look, so I don't want my bike engine to look like one.

All of that being said, if I happen to come into extra money (LOL!) I would like to try a 4 stroke just to compare. Also, if they ever make one that doesn't look stupid, I would definitely try it then.
 

nolan_speed

New Member
May 31, 2010
30
0
0
Seattle, WA
I wasn't saying that a 4 stroke was better for a bike, in fact I'd rather have (and do have) a 2 stroke. It's smaller, cheaper, lighter, more powerful and looks better than the 4 stroke, and the slightly higher fuel consumption is pretty much a non issue. In my original post I was talking about the advantages and disadvantages on 2 vs 4 strokes in general. They each have their place for different applications, where power to weight ratio is more important than fuel consumption, emissions, and longevity the 2 stroke wins.
 

Mac

New Member
Dec 3, 2009
486
1
0
Maine
Hmmmm...
I think what we need here is a 3 stroke, fires every 1.5 times, runs mixed gas every other tank, pulls the hills, quiet and less expensive. Just a thought, please hold the ammo.

Mac
 

meowy84

Member
Jul 18, 2009
239
0
16
Canada
My opinion is that the way things stand taking into consideration what's available in the marketplace now a 2 stroke is the better option for powering a bicycle.

Mainly, the 4 stroke kits available don't look as pleasing as the 2 strokes and they cost quite a bit more. But if someone started selling a 4 stroke that looked more like the old Ducati Cucciolo moped engines (see pics) with nice exposed rockers for a relatively reasonable price I think the situation would change drastically. Suddenly the easthetic would split in favor of the 4 stroke in my opinion.

As for power I say it all depends on gearing more than anything. 4 strokes typically have more torque on the lower end and a broader power curve whereas the 2 strokes have a narrower power band that peaks at a higher rpm. That's why you can't simply release the clutch from standstill on your 2 stroker and get going: not enough torque with just the single speed.

As for a 2 stroke being better because it has less moving parts it's like saying that in a fight you'd pick a wooden club over a handgun because the club has less moving parts. The HT 2 strokers available are quite troublesome/finnicky enough (mainly because of poor materials and manufacturing)for only about half the moving parts of a 4 stroke.
 

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Dan

Staff
May 25, 2008
12,765
115
48
58
Moosylvania
I have and enjoy both. Out of the box/kit 4s have more power and speed. Really like the just pull up to the pump with the 4 smokers. Really like the size, sexy and weight of the 2 strokes.

If ya held a gun to my head and made me choose, I would pick the one I was riding but the 4 strokes seem to be the most used. The smoother sound and ride seems to clinch it for me. But is really just a personal preference.
 

Comrade Alfonzo

New Member
Jul 15, 2009
143
1
0
Whidbey Island, WA
"I prefer the 2 strokes for all of the above reason, but especially the power thing. For what they weigh, they put out plenty of power. Parts availability and the fact that many parts are interchangeable from one manufacturer to the other. Face it, the Chinese factories are probably all working from the same set of blueprints anyway. And then there's the looks, I don't like the way lawn mowers look, so I don't want my bike engine to look like one.

All of that being said, if I happen to come into extra money (LOL!) I would like to try a 4 stroke just to compare. Also, if they ever make one that doesn't look stupid, I would definitely try it then"

BLUEPRINTS, WHAT BLUEPRINTS. They asked a 5 year old to draw a bike with an engine with a crayon on the back of a door, then tok pictures and built accordingly
lol
 

[email protected]

New Member
Sep 25, 2009
117
0
0
San Diego
I didn’t really read everyone’s input, but the gist seams to be the same.... 2 strokes make more power..... You guys serious? I’ve built a few 2 strokes, and never got one over about 25 (never did used a speedo on one, but it felt about 25).... I’ve built a couple 4 strokes and I do like 35 up hill (with a speedo, and also... it feels that way)... what did I do wrong on the two stroke to have to disagree so much?

cost three times as much and worth every penny!