2stroke vs 4stroke

GoldenMotor.com

Jim C

Member
Jul 11, 2010
200
6
18
Long Beach Calif
Wow looking at the photos of Scotto's bike makes me want to rethink my entire engine mounting system. I do like the T belt drive it is the centrifugal clutch that I am not really happy with. On initial take off I get some pretty hard vibrations with a slipper clutch and a more solid motor mounting I am thinking it would really smooth out.
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
heres a video of the 4stroke kit you can get just about anywhere online http://www.youtube.com/watch?v=uPT6iZlPZw0

recommended sites to buy from:
-gasbike.net 349.99
-bikeberry.com 349.99
-kingsmotorbikes.com 199.99 speical

gasbike and kings motors are essentially the same company
They are exactly the same company and you made a mistake on the $200 price for a whole kit.

PS The so called "5G" Bikeberry kit with it's inferior gearbox should be on the do not buy list instead of a recommended list.
 
Last edited:

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
As he rides off on his Moped? Huhhh? When a moped grows up, does it become a MOTORCYCLE? Or are they motorcycles with pedals? And why

Just joking of course.

4-Strokes pretty much RULE however! (just behind the electrics lol
Yeah.. a 200cc Two Stroke CC for CC against ''match up'' would beyond a shadow of a doubt leave your 200cc Harbor Freight utility engine plain ol gasping.....well that Four Stroke would look like two, three, day,, weak old DEAD ROAD Kill :D:p laff

That is a natural Fact Jack :)dnut
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
Yeah.. a 200cc Two Stroke CC for CC against ''match up'' would beyond a shadow of a doubt leave your 200cc Harbor Freight utility engine plain ol gasping.....well that Four Stroke would look like two, three, day,, weak old DEAD ROAD Kill :D:p laff

That is a natural Fact Jack :)dnut
I was just talking to a minibike and kart racer that wants to build a KT 100 Unlimited Class racing motorized bicycle for the next race.

Would be a light fast bike!
 
Last edited:

biknut

Well-Known Member
Sep 28, 2010
6,631
409
83
Dallas
As he rides off on his Moped? Huhhh? When a moped grows up, does it become a MOTORCYCLE? Or are they motorcycles with pedals? And why :D

Just joking of course.

4-Strokes pretty much RULE however! (just behind the electrics lol)

dnut
Mopeds never grow up. They're always just gay little mopeds lol.

 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Yeah.. a 200cc Two Stroke CC for CC against ''match up'' would beyond a shadow of a doubt leave your 200cc Harbor Freight utility engine plain ol gasping.....well that Four Stroke would look like two, three, day,, weak old DEAD ROAD Kill :D:p laff

That is a natural Fact Jack :)
Yeah......really? Why don't you just build one then, bring it to a race and show me?

(i've only raced [and owned] 2-strokes most of my life)
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Regarding gasbike, kings and bikeFerry...
They are exactly the same company and you made a mistake on the $200 price for a whole kit.

PS The so called "5G" Bikeberry kit with it's inferior gearbox should be on the do not buy list instead of a recommended list.
Nationwide Access LLC in Van Nuys, CA is the importer of the YD factories Grubee Skyhawk 2-stroke engines, the ONLY 2010+ EPA certified 2-stroke engines legally allowed in the USA.

The 49cc 4-stroke HS engine is EPA certified and pretty much a part for part clone of the workhorse 50cc Honda you see on commercial job sites running generators and compressors from sunup to sundown for years and years.

Unless you break the pull start rope they are great little reliable workhorses.

The 4G belt drive is nice and quiet when running but the clutch bell rattles like someone ringing a bell at idle which is annoying but liveable.

They are gutless for the most part to get them going but wind up nice, especially if you run them with gears, even a 3 speed like this.



And for hills not so great when direct drive like this...



... but do with some pedal help.
I am building another one of those now, the bike is here and 4G kit from gasbike is on it's way but there are other options like the 79cc HF Predator for $100 but once you add up all the other parts you'll need that come in the gasbike.net kit it will still be at $350.

I am about a week away from starting a completely custom 4-stroke build with this 6.5 HP (212cc) 4-stroke engine
http://www.harborfreight.com/65-hp-212cc-ohv-horizontal-shaft-gas-engine-69730.html



And this Auto-shifting Torque Converter transmission.

http://gokartsusa.com/GTC-TC2-Gokart-Torque-Converter-30-Series.aspx



There is a big difference between a centrifugal clutch and a torque converter.
Both are automatics meaning don't engage at idle and self engage when reved up, they just do it differently.

A cent clutch has a set of spring loaded pads on the engine output shaft that spain out and grab the inside of the bell housing that has a gear or belt sprocket and single speed and as mentioned before that bell tends to ring like one at idle.

A TC works differently and actually acts like a 3 speed transmission.
This is an excerpt from the link I posted above.



In short that front belt pulley gets larger as the RPM's go up thus changing your initial gear ratio which to me is cool as **** and I can't wait to try one ;-}

I think a kit with everything needed to center mount a 4-stoke including a decent light torque converter on a bicycle but with no engine that would take the HF 79cc or other HF sizes up to a 212cc you can buy at any Harbor Freight or a 50cc Honda or HS just as easy to buy locally would be a very saleable 4-stroke option for the do it yourselfer.

Kind of like a universal 4-stroke bike mount kit and you just buy the 4-stroke engine of your choice.

One final note on center mounted 4-strokes, kiss your bottom bracket pedal assembly, it's sprockets and shifter goodbye, unlike a 2-stroke your standard bike pedals won't fit around the much wider and heavier 4-stroke engine so you will need to replace the whole works with wider ones and that can really feel awkward unless you have ever rode a real motorcycle.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
I worked on small engines in a small engine shop here in town. In just one year every two stroke I came across was more better CC match for CC each and every time. The conciseness in the shop was always the same.

Don't need to race to figure that one out. Besides you forgot that way smaller CC two strokes at your races were able to keep up with you.. Conveniently already? So right back to a CC match I say No way..

Plenty internet forums is riddled with folks saying stuff like my 450 for stroke is faster than a 250 two stroke. :)

All your racing at that track was total cheating having 100 plus more CC than every body around you. Why don't ya beat them with the same CC capacity. Answer is ............easy you can't!dnut

I am just over joyed I don't live by Cali rules. Get to simply use what works perfectly for me over here.. Man you pour pour folks are just stuck with those four strokes over there. So So Sad.

Every thing I read here says known to cause cancer in the state of California. Glad I live here.laff


http://en.wikipedia.org/wiki/Power-to-weight_ratio
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
Regarding gasbike, kings and bikeFerry...
Nationwide Access LLC in Van Nuys, CA is the importer of the YD factories Grubee Skyhawk 2-stroke engines, the ONLY 2010+ EPA certified 2-stroke engines legally allowed in the USA.
★★★★

I guess you did not hear the news ......better stock up.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Plenty internet forums is riddled with folks saying stuff like my 450 for stroke is faster than a 250 two stroke. :)

All your racing at that track was total cheating having 100 plus more CC than every body around you.
It's not cheating when you are racing the "Unlimited Class" doughnut hole.....you can build a bicycle with a Maico 501cc 2-stroke engine as long as it is a single speed tranny and doesn't have motorcycle tires on it and race in the BIG class.....yes, Unlimited!

Everyone that knows anything about 2-stroke vs. 4-stroke power KNOWS that you need at least double the cc's of a 4-stroke to equal that of a 2-stroke......duh.

I built my bike to race against and beat Morini's just like your's.....and it does just that! Why don't we ever see you at the California cancer causing races??? Winning or losing?

Chill until we do....
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
It's not cheating when you are racing the "Unlimited Class" doughnut hole.....you can build a bicycle with a Maico 501cc 2-stroke engine as long as it is a single speed tranny and doesn't have motorcycle tires on it and race in the BIG class.....yes, Unlimited!

Everyone that knows anything about 2-stroke vs. 4-stroke power KNOWS that you need at least double the cc's of a 4-stroke to equal that of a 2-stroke......duh.

I built my bike to race against and beat Morini's just like your's.....and it does just that! Why don't we ever see you at the California cancer causing races??? Winning or losing?

Chill until we do....
There you have it two strokes rule. You left out the part about a 49cc two stroke that kept up. That is embarrassing. You had to use a 200cc motor to win.laffThat is not cheatinglaff
Since win do I have to come to a race to figure that out? Everybody knows two strokes rule. nananana tag your it.

Just messing with ya buddy. You have a friggin outstanding machine and I would be very very proud of it you absolutely should be!! That bike kicks butt!! One of the nicest features is the way the engine brake works for you in the turns. Really a perfect bike. Especially for racing!

Think I will have a cigar now it is safe to smoke here and there is no Malathion spray falling from the sky right now.. It is clear to ride out side on my 20,000 mile old Morini that runs every bit like day one. Cuz they rule pound for pound size for size.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
There you have it two strokes rule. You left out the part about a 49cc two stroke that kept up. That is embarrassing. You had to use a 200cc motor to win.laffThat is not cheatinglaff
Since win do I have to come to a race to figure that out? Everybody knows two strokes rule. nananana tag your it.

Just messing with ya buddy. You have a friggin outstanding machine and I would be very very proud of it you absolutely should be!! That bike kicks butt!! One of the nicest features is the way the engine brake works for you in the turns. Really a perfect bike. Especially for racing!

Think I will have a cigar now it is safe to smoke here and there is no Malathion spray falling from the sky right now.. It is clear to ride out side on my 20,000 mile old Morini that runs every bit like day one. Cuz they rule pound for pound size for size.
You just keep forgetting that I love 2-strokes, but 4-strokes RULE ! What more can I say? rotfl Go back and read this whole thread now and you'll see perfectly clear......1,2,3, 4-STROKES RULE!

dance1
 

biknut

Well-Known Member
Sep 28, 2010
6,631
409
83
Dallas
4 strokes, that's just so many strokes to have to deal with. I'd rather have a 1 stroke.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
A steam engine could be cool....yet hot. Two 1/2 strokes perhaps?
How about no strokes?
Just get a Rotary engine like the old Mazda's tried, remember the commercials with the '... but the Mazda goes hummmmm'?

They have prototypes of something you could fit in a bike but they are 6 figures in cost, I have the e-mail exchange but it's a moot point, I just thought it was as relevant as a 1 stroke ;-}

Sure a 2-stroke will kick butt on a go-kart track, but see who rules on a Nascar track, and for every day commuters, just decide which type of roadway you will follow for you commute is more like, a go cart track or a big oval, and go from there is my advice.
 
Last edited:

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
How about no strokes?
Just get a Rotary engine like the old Mazda's tried, remember the commercials with the '... but the Mazda goes hummmmm'?

They have prototypes of something you could fit in a bike but they are 6 figures in cost, I have the e-mail exchange but it's a moot point, I just thought it was as relevant as a 1 stroke ;-}

Sure a 2-stroke will kick butt on a go-kart track, but see who rules on a Nascar track, and for every day commuters, just decide which type of roadway you will follow for you commute is more like, a go cart track or a big oval, and go from there is my advice.
A Wankel......howabout nuclear, as in atomic?!
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,145
7
38
Nor*Cal
It's not cheating when you are racing the "Unlimited Class" doughnut hole.....you can build a bicycle with a Maico 501cc 2-stroke engine as long as it is a single speed tranny and doesn't have motorcycle tires on it and race in the BIG class.....yes, Unlimited!

Everyone that knows anything about 2-stroke vs. 4-stroke power KNOWS that you need at least double the cc's of a 4-stroke to equal that of a 2-stroke......duh.

I built my bike to race against and beat Morini's just like your's.....and it does just that! Why don't we ever see you at the California cancer causing races??? Winning or losing?

Chill until we do....
Hold up hold up hold up!!!!
We all know that in the unlimited class, you're allowed to have a two speed moped with race tires. Haha jk Realistically the Morini wasn't enough cc's on the track to race in the unlimited class. It was only a 1/4 of the cc's of the 212cc monster.
You're lucky Scotto, El buddy of mine. If I didn't retire because of the risk vs the reward syndrome or racing against the mopeds. I would build a KT100, KPV100 or a 125 tag that would smoke any bike out there.
But then again...I'd rather be a spectator and share an ice cold one with you and the guys after you smoke everyone out on the track. :)
See you at the next Grange race on my blazing fast 1k watt eBike.