4 Cycle VS 2 Cycle HEAD TO HEAD Testing

[Irish John]

The 2 stroke pulls harder and has more top speed. I figured the 4 stroke would win on top end...Because of the 36T. I was very surprised to see that the 2 stroke with the 44T still had me on top end. But...It was close on the top end.. Eventually we were about the same on top end but by then the 2 stroke was way up the road by then since it pulled harder. I guess I could have dropped my 4 stroke back down to a 44T..But..Then I would have been killed totally by the 2 stroke on the top.


But if you had raced each other over 5 miles it would be like the snail & the hare. You'd have passed the 2-stroke near the end when his engine mounts snapped off or when he sucked his chain into the drive chamber and flew over the handlebars. Maybe you'd have got lost in the blue cloud of unburnt oil that the 2-stroke left behind it.
Seriously I am sad to read that the 4-stroke hadn't the edge at the top end - I thought they had a top speed of 40mph with a 56 tooth rear sprocket and have just invested heaps of money in a 4-stroke kit on that information.

 

[azbill]

bear in mind that dax sells the 2 strokes (and NOT the frame-mounted 4)
I have not heard of anyone killing a 4 stroke...but have done in a few 2's myself
the four still wins in reliability

 

[HoughMade]

Keep in mind that this report was from before Dax himself started selling 4 strokes. He has stated that with a 36t sprocket, his setup can hit 41.7 mph.

I don't know what the reduction on the Dax 4 stroke setup is, but a 36t with a Grubee will not allow it to operate in the engine's power bnd with is fairly high on the rpm scale.

 

[Quenton Guenther]

Sorry, but I find many of these comments funny, and please don't take offense, because this debate has been going on for as long as I can remember. When I raced motorcycles, a large number of races were won by 4 strokes because they actually finished most of the races. Although my Ducati "Desmo" was very fast, and often out powered the 2 stroke competition, the few times a 2 stroke took the lead, I just had to wait for it to self-destruct to win the race. Don't take this wrong, because I raced a lot of 2 strokes during my career, and the 4 strokes did need some attention prior to starting each race. I always had to make sure it had gas, and a soft rag to wipe off the dust, whereas the 2 stroke rides required at least several days of prep before each race. In order to make a 2 stroke competitive I had to purchase many sprokets [because of the 2 stokes narrow power band], main jets, and part interest in a spark plug company [just joking]. I will say that I never lost a race with a 4 stroke because of breakage, but every 2 stroke I ever raced [Kaw, Yam, Bul, AJS, & Carabela] let me down many times. And if anyone thinks a 2 stroke needs less maintance than a 4 stroke because of less moving parts, I will offer history as proof of a failed concept. While it is true a 2 stroke fires every time, and has less parts, it still works on the principle of the "sealed pump", and must be a quality unit to last for a long period of time. I once had a official from Kawaski tell me that their motor was at its peak when everthing was new, and due to crankcase seal wear the motor was less reliable each minute it was run. In defence of 2 strokes I need to state that in comparing "small" motors, the 2 stroke has less weight, cost less, and will supply more power than a similar 4 stroke motor, but is in no way more durable [or even close]. So if you want to go fast for a short period of time go with a 2 stroke on your bike, but if less maintance, less vibration, and long term durability, are important issues, consider the 4 stroke option.
I guess these comments are "mute" because of the ban on 2 stroke bike motors, but facts are facts, but remember I actually like both 2 & 4 stroke motors, but for different reasons.
Have fun,
Quenton

 

[Irish John]

I guess these comments are "mute" because of the ban on 2 stroke bike motors, but facts are facts, but remember I actually like both 2 & 4 stroke motors, but for different reasons.
Have fun,
Quenton

I like 4-strokes and 2-strokes but I don't like really shoddy engineering of any stroke. I too remember the 70s when 4-strokes just couldn't compete on the race circuit and especially in road racing. They were out there though and you could hear them from miles off but the 2-strokes were only audible at fairly close range. If you had your ear broadside on to a 2-stroke the noise was actually painful. The privateers all raced Yamahas on Seely frames. Yamsels they called them.

 

[Quenton Guenther]

Hi Irish John,
Noise? Long after I lost a major portion of hearing in my right ear, the AMA started the muffler rule [too late for me]. And one thing for sure "nothing" was as loud as the Ducatis with the long black megaphone exhaust pipe. When I started my Ducati at any track it drowned out everything. Of course I raced the Yamaha twins on the dirt tracks [flat track] and they were also un-muffled, and were extreamly loud and very high pitched, and was harder on my ears than the louder Ducatis because of the difference in the tone. Even when I rode the Harley XR750 the AMA hadn't yet required mufflers. I remember the mad craze to get all the race bikes to work with the new muffler rules, and the 2 strokes took the biggest hit in power, because messsing with proven expansion chambers proved a real challenge. I even remember slipping the muffler over the stinger to look like it actually worked, and many tracks didn't stop us for a long time. On one of my 250 Ducatis [at an indoor short track in Hamilton, Ohio] I used the megaphone exhaust directed into a Folger's coffee can stuffed with steel wool [did you know steel wool burns?] I think I won that night because of the "smoking" exhaust system.
Have fun,
Quenton