2 or 4 Stroke?

[seamus26]

I'm fairly new to the scooter scene, but I've seen some people rip on four stroke engines a little.

What are the trade-offs between the two? Just for information and lively discussion.

[Madathlon]

4 stroke runs off of pump gas just like your car. 2 stroke will either have a oil tank or you have to mix your fuel with oil.

[Vision]

2 stroke has more power for the size but you have to deal with keeping oil and gas tanks full. They smoke more. I like the low end power of 2 strokes but it's not worth it when buying a bike IMO. Get a 4 stroke and a larger engine, 125cc for instance.

[seamus26]

I like my 150 four stroke. Do the two strokes have to meet the same emissions standards?

I remember my brother's two stroke dirt bikes. They seemed loud and dirty. He had a couple of Yamaha Banshees back in the day. They were terribly fast, but smoky.

The four stroke just seems like a better option all around. Thanks for the comments.

Any two stroke fans out there?

[wheelbender6]

Most recent two strokes are 50cc like the pre2013 Yamaha Zuma and some 50cc Aprilias and Kymcos.
The Genuine Stella was a 150cc two stroke until a few years back, if memory serves.
-My opinion is that if you plan to ride a 50cc scoot, I would get a two stroke, even if I have to buy a used one. For bigger scoots like 125cc and above, I would stick with a four stroke. Just my opinion.

[kz1000st]

I had two stroke motorcycles for years. A tank of oil in mine lasted 600 miles. Hypothetically since it fires on every stroke a two stroke can put out the power of a four stroke twice the size. They also weigh less. On the down side since the oil is contaminated by gas piston rings may not last as long as four stroke's.

BUT. That usually means they'll only last 20,000 miles in normal use and darn few people keep them that long.

[Madathlon]

The worse part of Newer 2strokes is the oil mixer pumps. I have worked on Marine 2 strokes most of my life and I can tell you there is NO warning when the pump fails. Well except for when the engine seizes up and leaves you stranded.

[kz1000st]

I don't know about marine engines but I had a 500cc, three cylinder two stroke for 30,000 miles and six years without trouble. Even on a four stroke pumps can fail. That wouldn't concern me.

[Madathlon]

Originally Posted by kz1000st

I don't know about marine engines but I had a 500cc, three cylinder two stroke for 30,000 miles and six years without trouble. Even on a four stroke pumps can fail. That wouldn't concern me.

Your right on that a 4 stroke oil pump can fail, but most 4 strokes have low oil pressure kill sensors.

[Cyborg]

KZ did you have a suzuki 500 triple??

[Cyborg]

they do make more power just in the fact they fire on every stroke,,,if i were to have a 50 it would be a 2 stroke

[kz1000st]

Nope Borg. I had the real deal. A 1974 Kawasaki H-1 KH500. It was an awesome motorcycle. Even then it was only marginally slower than a Kawasaki 900cc Z-1 which was only a toss up in speed with an H-2 two stroke triple. The difference was that a Z was more civilized.

"Your right on that a 4 stroke oil pump can fail, but most 4 strokes have low oil pressure kill sensors."

Maybe on some engines but I can tell you that somebody on another forum fried his GY6 motor when the oil pump ceased functioning. He heard a strange noise when the chain fell off the pump, rode like 10 miles home and it smoked like a fiend. Yes, of course, pre-mixing the fuel on a two stroke is the only safe thing to do but many mixing pumps compensate for load and throttle position for more efficient use of the oil.

On my Kawasaki the pump had a cam shaped cable actuator that poured more oil in at bigger throttle openings. You should have seen it smoke when I blew past Harley Sportsters. The Japanese must have been inspired by WWII destroyer smoke screens.

[Cyborg]

ah back on again,,,,,,yes i was going to edit my post but had some kind of glitch so i couldn't get back on,,,anyways i was going to say silly me i know you're a kawi man and should have said h1,,,,my 2 were super low mile suzi's,,and they were pedestrian at best so i left the cleaner of the 2 alone and hotrodded the other,,,,fun

[carasdad]

Originally Posted by kz1000st

I don't know about marine engines but I had a 500cc, three cylinder two stroke for 30,000 miles and six years without trouble. Even on a four stroke pumps can fail. That wouldn't concern me.

I had a 750 Suzuki 3 cylinder water cooled 2 stroke...put just over 36,000 miles on it before it needed rings. 750 2 stroke!! Eeesh talk about quick...
I currently have a 2008 Adly Thunder Bike 50 2 stroke with a 72cc BBK.. It has 7,900 on the BBK. Only failure I ever had was on the stock 50cc top end. I left the oil box cap off while filling it...went inside to get some coffee and unknowingly the neighbors 3 yo poured water into the box. (which of course settled to the bottom..and the oil floated up) I started it and ran 2 miles...causing it to seize.. Pulling the oil line I saw water drain out..so I emptied the reservoir into a 2 liter Pepsi bottle and saw 3 inches of oil..with 1/2 inch of water at the bottom of the bottle!! The Adly is old..but still looks and runs like new. I also have a few 4 strokes... Jonway Sunny's.. I like both 2 stroke and 4 stroke.. The 2 stroke is super fast off the line and top end is 56+mph...good for zipping in and out of heavy city traffic...however it does not like long rides such as 20 miles each way at high speeds..it tends to run hot and lose power...no matter what main jet I use. The 4 strokes are good for long trips and I have easily done several 120 mile round trips.. They get better mileage than the 2 strokes also. The 4 strokes have 80cc BBK's in them so they have good takeoff and power...albeit not jet like such as my 2 strokes. They will hit 48-50mph...but prefer to cruise at about 45mph so they don't rev at 8,000 rpm. 2 strokes are ok with cruising at 8,000 rpm...but 4 strokes are pushing the engine when ya do that. Lastly.. 2 strokes are being phased out so parts are now harder to find...and when ya do...they are costly. 4 stroke parts are a 'dime a dozen' and can be found everywhere at a much lower price. Sooo you must ask yourself...what kind of riding you plan to do.. Zipping around town with an occasional longer trip...or lots of long runs.. i.e. 20-30 mile trips. NOT saying a 2 stroke cannot make long trips..but I find they wear more when ya do. Ya see..I LOVE both...therefore I have both as they both have attributes the other does not have. So just buy 2 Scoots...

[ventoman]

2 strokes sound like a weed eater. 4 strokes sound like a lawnmower. 2 strokes are faster. 4 strokes last longer between rebuilds. Parts getting harder to find for 2 strokes. Parts galore for 4 strokes. I have both. And I enjoy them both.