Difference in 250F and 250-2

I was reading the july 2007 MXA mag and came across an article about the difference in 250F and 250-2. it says that a 250-2 makes 33% more power (50 to 35). and that it cost five times less to rebuild a 2-smoke.

Discuss

J_Mad18

In Australia, there seems to be a a big shift of people going back to the 2-strokes after they sell their 1st or 2nd 4-stroke. GasGas EC300's and KTM300exc's seem to be popular for the trail guys and YZ250's for racing. I think Yamaha has done the right thing (business wise) by keeping the 2-strokes. They are still selling lots of YZ125's and YZ250's down here.

I had a YZ250F and sold it, now I have a YZ250. Theirs a huge power difference. Although the YZ250F is more rider friendly, the YZ250 has some serious balls. Not to mention it's close to the same weight and it's way cheaper to own and even more so when racing. I race the Pro classes and this YZ250 is what keeps me racing, I gave the thumper a shot and although my results were good,the costs of the damn thing were to much at that level of racing. The 250 2-stroke gives me a better shot against those 450's at a way cheaper cost.

I personally dont think that 2-strokes are any cheaper to own. Sure, they are cheaper to rebuild but you have to rebuild them a lot more often.

You would go through 2 or 3 topends a year on a 125, whereas you could get a couple seasons of riding out of the topend of a 250F. The same goes for a 250 2-stroke vs 450 4-stroke. You will need to replace the topend of a 250 2-stroke about once a year, but you could easily get 3-5 years of riding out of a 450 before it needs a new topend.

The cost of a topend rebuild from a 2-stroke to a 4-stroke is about the same (about $150) and other than adjusting the valves every once in a while, there isnt really isnt much to maintain on the cylinder head of a 4-stroke.

I had looked into getting a 2-stroke for the cost, but I found they arent really any cheaper than a 4-stroke.

4-strokes are a lot more durable than 2-strokes because pure oil is a much better lubricant than a gas/oil mix. 2-strokes are simpler and easier to maintain because you dont need to worry about checking/adjusting valves, but I disagree with the notion that they are cheaper to own.

You must not ride much Bakemono!

3-5 years out of a 450 top end?

You must not ride much Bakemono!

3-5 years out of a 450 top end?

+1. And $150 for a 4T top end? You can't just toss in rings and a piston. You also need a cam chain, valve guides and seals, and possibly valves as well.

I ride a lot, and I ride relatively fast. One top end/year is about right for the 2T, but I'm also expecting to have to do my 250F as well. The valves needed adjusting after ~12 hours, and I expect they'll need it again before too long.

Oil/filter changes on the 250f cost a little more than premix/gearbox oil for the 2T, but it's close. The 250F does win in rear tire life though.:thumbsup:

I can get 6 months of racing out of my YZ250 on a topend, if not more. On a 450F, I would most likely be looking at a complete overhaul at the end of the year. Parts for my YZ250 for a new top end (gaskets included) run me about $110. On a 450F, once things start wearing out, they need to be replaced, especially when ridden hard. So now your looking at new piston, rings, gaskets, valves, etc etc. That's gonna run me about $400 or more if I do it myself.

And the other guy made an awesome point about the oil filters and oil. Although I have to buy premix for my 250, it's a lot cheaper than a new oil filter and a couple quarts of oil that I should be replacing every few rides.

Four strokes cost way more.

wow i'm surprised how quickly you guys go through valves. My bike is an 02' and when I bought it used I checked the valves and they were in spec and now after around 500 miles they are still perfect. Maybe my bike is just special?:excuseme:

wow i'm surprised how quickly you guys go through valves. My bike is an 02' and when I bought it used I checked the valves and they were in spec and now after around 500 miles they are still perfect. Maybe my bike is just special?:excuseme:

It depends on how hard and how often you ride the 4-strokes, KYMXRacer rides a lot and races in the "Pro" class so he's probably pretty hard on his engines. Those of us that ride for fun will have less wear than those that practice, ride near or at WOT and race a lot.

If you do mostly trail rides for "fun", your engines can last a loooong time :thumbsup: but if you're at WOT most of the time, your engine will need more maintenance and overhaul.

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