EC 250 VS EC 300 Whats the Diff??

[FFRDave]

It is widely said that "Theres no replacement for displacement". However, I wonder, is 50 CCs really significant ?

I understand that these machines are very lightweight, but it seems that Gas gas might have made a two stroke EC 400 or 425, and gained 150cc or 175cc.

I saw a 2005 EC 300, and I have a 2005 EC 250. I still am very very very very happy with my 250, but that 300 was really calling my name. I have enough money into mods for my 250, that I really hate to sell it.

So, again, what difference do those extra 50 cc's really make ?

[Bultaco206]

I believe they make the same horsepower - but the extra displacement makes for a wider powerband and increased torque. The 250s I've ridden revved quicker with more 'hit.'

My 300 likes to be short-shifted and to let it pull. If you let the revs build - things happen quickly and it becomes a handful.

[iancp5]

The 250 makes the power at higher revs and the 300 has more torque, especially low to mid. Which is best depends on your style and what sort of riding you do. An advantage of the 250 for everything would be less vibration but I don't even notice it on my 300 anymore.

For an average rider and short races I imagine the 250 would be best. For longer, tiring stuff the 200 and for technical stuff probably the 300. But I think so much depends on rider style and preference you could reverse that for many. My reasoning is; 250 you can open it up, let it rev and it's fast without being too wild until the revs get up up. The 200 has just less all round but still plenty so wont tire you, it feels nice and light. The 300 can pull from very low revs so is good at pulling through difficult stuff without bogging or spinning up where you would try to stop a smaller engine. It can be tiring as there is a lot of pull in the midrange or even right off the bottom depending how you set it up.

[Hawkeye]

I thought my brothers '02 250 I rode was lacking torque compared to my '02 300 and was really no easier to ride. My friends '02 200 has always lacked bottom end and runs like a sewing machine. He parked it and got on a 300 and loves the smooth power delivery for trailriding and racing.

300's vibration is no worse than a KX or YZ250. KTM used to make a 380, now they don't. Ride a 300 2 stroke and you'll see that it is hard to ask for more. Plenty of power, just not as broad delivery as the new 4 strokes. Going larger with cc's on a 2 stroke would just increase vibration and make revving it out less desirable, IMHO. Plus I would think the low end would come on too strong and generally mess up the delivery.

I just got a new leftover YZ250 and it probably has the best power delivery of any 2 stroke I have every ridden. Really sets the standard for delivery and boost. Very strong motor that compares to a GG300 in it's delivery. Wow. The YZ got there with a lot of technology and 6 years of refinement to their engine design. GG got there by adding 50cc's to their aging 250 design. I'm happy either way.

[GMP]

The 300s are strong off the bottom. You twist, it pulls immediately, just like a big 4-stroke. This is fun, initially so much fun you don't realize that you may be holding on tighter than if you were on a bike with less torque. Its subtle, but it can add up, and make you tired faster. I think that the few instances where the 300s torque can bail you out are offset by the yank on the arms every time the throttle is cracked. A good running 250 has more than enough to get the job done with basic skills, especially the GG 250. Look at the nationals, how many top guys are on 300s or 450s? Why waste energy managing power you don't need? All the top guys are on 250s, and Lafferty rode the KTM400, NOT the 450. Of course there are exceptions like the kid who won NETRA, but he's 18, not middle age like most of us. This is not just my opinion, I spoke to a few fast guys about it, because I'm considering going with a 250F. Thats one reason why the 250Fs are so popular, just enough and not too much. I suppose you can say that the smaller bike is less physically demanding but more mentally demanding to ride.

Now, this is all relative to racing in the woods, for just casual riding especially on open terrain anything goes and 450 4-stroke that wheelies at the crack of the throttle is great fun.

[iancp5]

I agree with GMP. For a lot of racing in the UK most find a 200 more than adequate. Our stuff is mostly tight terrain. For trail riding I prefer a big bike that doesn't need to be revved. I have a 300 for racing by accident because when I bought it I needed it for trail riding too. Now I have a 450 for that I wish I had a lower powered bike to race. In fact a 250F or a 200 smoker would be best. Sure I'll be a bit slower at the start but I reckon I'd easily make that up towards the end. Strangely for really technical stuff I think the 300 is the best but that's maybe because you can use the bottom end torque & keep the revs down, it's the non-technical but twisty or bumpy stuff it gets tiring on.

But ... I love my 300. Until I'm tired that is! I also have it set up how I want and I'm too lazy to go through the hassle of selling it and getting another bike sorted.

[Hawkeye]

I think the terrain is a big factor in the preference. Out here in the midwest we have more open fields and pastures that let you really get on the throttle. I've ridden all three bikes and I really think I'm faster over two hours with my 300. I do swear by my G2 throttle for modulating the low end delivery that GMP is talking about, I only go back to the stock cam for playing on the MX track. Racing a 300 lets most B level riders tap into that "lazy man" or "three stroke" power delivery (that trailriders are always glowing about), that lets you mess up during a race and still recover quickly. With a lot of rocky terrain, I could see where the 300's wouldn't have any real advantage over a 250, and the 250 would be easier to bump start from a low speed stall.

Ian, I don't know what kind of snot you must have to ride in over there, but I found the 200 so mentally tiring to ride, let alone race. One mistake like being in the wrong gear and it's like the brakes are dragging. A and AA racers don't get in those types of situations, so smaller displacement bikes are lighter (or have less gyroscopic crank effect and "feel" lighter), hence one reason why top riders like Shane Watts and Fred Hoess pick them.

[GMP]

Our trails are either very tight (bar/sub bar width), very rocky, or both. With a 300, you find yourself using the clutch to modulate the power, instead of gaining revs to get power. For me it seems like more work. Too much power to soon.

I would love to have a programable CDI, that I could remap from my PC like I did with my Cannondale 440 EFI system. There is a lot of flexibility there. I was able to retard timing and tame the beast off ide so it was very smooth in the tight stuff.

[FFRDave]

GMP,
You mentioned a programable CDI. I agree that it would be wonderful to be able to make changes to one or both of the map curves on the duel map CDI.
You seem to know what your talking about, so I have this question that has been on my mind.

With regards to the Duel Map CDI, Which parameters are being altered by the CDI unit? Is it just a matter of retarding or advancing the ignition timing?

Fuel mixture is handled by the carb, and air is taken in through the airbox. It takes air, fuel, and a spark to make a cylinder fire off. Spark timing seems to be the only parameter left to alter in order to change engine performance.

[GMP]

Yes, in the case of a CDI only, the timing curve in relation to RPM is what is changed. If the system has a TPS, throttle position comes into play as well. Gear position as on the Husky TEs adds yet another dimmension.

When we introduce fuel injection, its much more complicated. There are two matricies based on RPM and throttle position, one for ignition advance, one for fuel mass. This is the base map. This base map is then biased by ambient pressure, temp, and coolant temp sensors. Other factors such as attack and decay allow you to change throttle response in both directions. You can actually slightly alter the way compression braking feels. Its very cool. The Cannondale system was great with eaisly available very reasonable priced software, better than the GG system IMO.

I'm a beleiver in EFI having owned a bike with it, BUT, unless the tuning tools are within reach of the average owner, it will be less flexible than a carb system. I would not expect the Japaneese bikes to have flexible systems. What I bet will happen is what happend in the EFI road bike aftermarket. Piggyback modules like the Techlusion will become available to tune the mixture.