Bicycle Engine

[Black_Moons]

Heh. I think the problem is the 50CC rule, Now if they had a HP rule insted, it would make a LOT more sense to use a 4 stroke.. And would'nt allow you to just throw $600 at it and have an unlisenced 10hp 10,000rpm loud death machine, when it was rules aimed at little 2hp chinagirls.

Course, then the cops would need chinagirl dynos. Insted of.. uhhhh... the displace-o-meters they currently uhh, don't have!

 

[[email protected]]

Talked to a guy today at Walmart - has a Staton 4-STROKE Friction Drive on a Mongoose.
He regularly rides it 20 miles each way to the VA Clinic. Not a young guy.
I'm thinking of fixing up my old mountain bike with one. A Ross Mt Whitney -- no suspension.

 

[fishguts]

Too bad that twist an go thing would make them illegal to ride where I live.

Now ain't that weird - that's the only kind that are legal here (MA).

 

[buzbikebklyn1]

Make mine morini please

 

[Bulldogg at MAD Bikes]

The 2 strokes are lighter by a few pounds and can mount more easy between the crank for a better center of Gravity and cost less and have a life of 1000-6000 miles depending on how you treat them.

The 4 stroke is much smoother, much quieter, and the 4 stroke 48cc Titan will run with and even out run the 70cc 2 strokes. So when you consider the 50cc Titan with the 70cc Dax 2 stroke, the weight is pretty close. Also, when the life of the 2 stroke is nearing its end, the 4 stroke Titan is just getting broken in.Also since the 4 stroke mounts behind you, it allows you to install on a full suspension bike and makes for a super smooth ride, and it is even more quiet to ride with the motor back there, and there is nothing intrusive on the top bar or between your legs. Also.. The Titan 4 stroke is an automatic making for twist and go operation. Also, it makes better torque. Also, the Titan rear mount will allow you to mount to a step through frame making for easy mount and dismounts.

These 2 strokes do last a little longer then you mentioned. more like 7000 to 10,000 miles if treated with respect. But then again I have only the Grubee 66cc, 2 stroke GT5's (5 of them and all have over 7000 miles and all still running perfect, and I ride everyday.

 

[F_Rod81]

I have had a number 2 stroke and 4 stroke engines growing up. I like 2 strokes a lot better, easy maintenance, and more power = more fun.

 

[buzbikebklyn1]

Over the years I've had both 2 and 4 stroke engines in my bikes.
I hate to say this in print, but the China doll does have several design flaws (mostly repairable or modifiable) and reliability problems if not fueled and maintained properly
(as do all small engines).
In this aspect, my friction drive,rack mounted 31cc Honda 4 stroke GX30 engine was easier to live with day to day than the average frame mounted left side drive china doll (if not a bit boring performance wise and ungainly in appearance).

This next part is purely subjective on my part so PLEASE don't flip out you 4 stroke guys out there!

Now we come to my real point, 2 strokes are just plain cooler than 4 strokes.
I find a 4 stroke has to have at least twice the displacement of a 2 stroke to generate any kind of excitement.
The current crop of 4 strokes available for M/Bs still look like weed whackers to me, and don't look like they belong mounted in a bike frame.
Whereas the China doll LOOKS like it belongs bolted into a bike frame(let alone the mighty Morini).
It all comes down to subjective choice...
I still like the china doll for its easy maintenance and repair ability, but it doesn't have the "holly s--t" factor of the Morini.
4 strokes have some catching up to do style wise before they attain the "cool" factor.
What ever you choose, ride it like you stole it, have fun and take care of it with regular maintenance.
Its a big sport/hobby with lots of room for personal interpretation...
Keep em shiny side up...
BBB

 

[mopedjay]

theres no diesel engine on there i wanna diesel bike

 

[nate-m]

<blockquote>In this aspect, my friction drive,rack mounted 31cc Honda 4 stroke GX30 engine was easier to live with day to day than the average frame mounted left side drive china doll (if not a bit boring performance wise and ungainly in appearance).</blockquote>

I recently switched out my china 2-stroke for a Honda 50cc on friction drive.

I'm happy with this decision. It's quieter, smoother, more fuel efficient, and doesn't smell as bad. I still like the 2-stroke though. I want to get another bike and put it on that.

The differences as I see it (not a mechanic type)

+ More powerful. 200% more power strokes per rpm. At higher RPM it's not that big of a difference though.
+ simpler
+ lighter.
+ smaller
+ cheaper
- likes gasoline a lot
- smellier
- noisier
- top end wears out faster
- sustained travel at (relatively high) speed wears it out faster
- must carry around 2-stroke oil. Unless you have oiling system (none of these kits seem to have that) then you need to premix gasoline in separate container (ideally)


4-stroke:
- lower torque. Especially off the line
- more complex. You have the valve train.
- heavier
- typically more expensive
+ typically more efficient
+ quieter
+ less exhaust stink
+ longer times between overhauls
+ better at long distance at sustained speed
+ get gasoline at any gas station.


And it seems that 2-strokes are much more finicky with changes and fuel mixture. Like they will tend to foul plugs much easier then 4-strokes if they get out of tune. More sensitive to temperature changes (and other environmental factors) and jetting needs to be mucked around with a lot more. Although this could just because I have far less experience with small 4-strokes then 2-strokes. But I won't drive anywhere on a two stroke without having a extra spark plug in my bike's tool kit.


If you want something that is cheap, fast and good for jack rabbit starts. Fun and fast... then 2-stroke is where it at.

If you want something that will be traveling longer distances at sustained speeds then 4-stroke is what you want. Much more neighbor friendly also.

 

[Mike B]

I like my Robin Subaru 33cc friction drive twice as much as my 66cc grubee.

Less power, less speed, less acceleration, but more fun -

It just purrs down the road smooth as silk. Of course there is a better bike under it too, but that is as it should be.

 

[Elmo]

I like my HF 2.5. Good power, cheap, and very reliable.

 

[F_Rod81]

It all comes down to the owner/rider. If you know what your doing and treat it good then the 2stroke kits can be just as reliable as the any 4 stroke kit. I want both so I'm in the process of my 4 stroke build.

I will not get caught on a electric bike, not for me.

 

[kolbpilot]

Me ?, 25cc Homelite 2 stroke. About 2 stroke longevity, there is a video on youTube. This guy has a Kawasaki museum in England. Among many of the cool things he has in it is a speedometer from a Kawasaki 500 triple. 95,xxx miles on it. Impressive indeed.

 

[syates234]

So I have a 2 stroke and it hasn't been firing at all sounds lime ot wants to but it don't. I have got a new cdi (coil) but it still isn't firing. Any suggestions??

 

[kolbpilot]

Have you determined the spark plug is not sparking by visually looking at it with the plug out? Or possibly (rare) a defective plug?

 

[BigE]

My second bike was a 1975 Suzuki GT750 AKA The Water Buffalo. It was a 3 cylinder 2 stroke water cooled. My little brothers bike was a 1976 Kawasaki KZ1000 LTD 4 stroke. The Suzuki would leave that Kawasaki in the dust when it stopped burning rubber. BTW My first bike was a Honda CB100.
If you want to go fast and have fun doing it buy a 2 stroke.

 

[Greybeard]

I've had a few bikes, including 2 of the above mentioned Kawasaki triples. Neither of them were reliable, only one made it to 3000 miles. I've been tough on stuff, ran 'em hard.
Raced carts, bikes, and much modified fuel burning outboards, and I've never considered any 2-stroke to be as reliable as a 4 stroke. The however is that I have a Honda powered Straight bar Schwinn, a Honda powered Felt, a Solex clone on my mom's old Schwinn Hollywood, and a Tanaka/Staton/MTB. My first motorbike was a Travis, sold out of the back of Pop' Science or Pop' Mechanics in the '50s. Powerproduct's engine. Stuck it twice, and suffered catostrophic crankcase failure when the rod exited.

 

[BigE]

The 75 Suzuki GT750 I owned is now owned by a Cycle shop in Waynesboro TN. It WILL still smoke any 4 stoke that wants to take it on. The mileage has be be getting close to 100,000 I'm sure the guy who owns it now has freshened up the motor. Kawasaki's weren't nearly as dependable as the water cooled Suzuki.
These China Gas etc. Motors are NOT Suzuki's and they aren't meant to be reliable but neither are the Chinese built 4 strokes.
If you seriously want dependable buy a Honda.

 

[kolbpilot]

I've had 2 Kawasaki triples in my youth (teens), and, I wish I had both of them today. As a consolation, I do own a '76 Honda CB 550 K that is 95% original with only 11,xxx miles on it. Anyway, the first was a a 3 year old ('73) Kawa. 250, 13,000 miles. I thought it ran fine but I wouldn't beat a Honda CB350 twin. I was 17 & it was gone in a year or so. The second was a later model '76 500 with 7k mile or so but it (in hindsight) wasn't tuned properly & wouldn't beat the newer Kawasaki 650 four cylinder. I was young & didn't know how to treat engines. One realizes that 2 strokes will go the distance equal to their 4 stroke brothers. After all, what changes?, nothing really. Still a piston in a cylinder, only with a little different valving & oiling. Keep the piston speed down to sensible levels, same with overall temperature, & there ya go.

 

[BigE]

My first bike was a CB 100, the Suzuki 750 came next, then 2 Indian Mustangs then a 57 Harley. I have owned everything from a Yamaha Virago to a V65 Magna and even a Russian Ural. Needless to say I love Bikes and have always owned at least one. I'm 53 and the bike I want the most is a 51 Vincent Black Shadow. I almost had one last year but I got out bid. It went for $71,000.00.