It is cheap and I am thinking of buying it.
It is a 1994 Suzuki RM250. According to the seller it has Wiseco piston and crankshaft and a Renthal Fatbar handlebar
http://img9.imageshack.us/img9/2596/img0055psf.jpg
http://img9.imageshack.us/img9/6370/img0054b.jpg
Is it any good or should I look for something else?
What are you intending to use the motorcycle for? That makes all the difference.
It’s an old dirtbike, which apparently lives in the ghetto.
I wouldn’t buy it unless I had the compression checked out ok, and knew the rest of the mechanicals were at least in-line with asking price.
How cheap is cheap? It certainly has some character to it, aesthetically. Make sure it is in good shape mechanically, of course.
Off roading and generally wrecking havoc around the city streets 
Is there a quick and dirty way to check the compression sort of taking it to a mechanic?
The price is 950 euros. All you can buy with that money is a chinese knock-off moped.
I have no idea what a “Wiseco piston and crankshaft” or a “Renthal Fatbar” are, but I am going to assume they are performance mods. Are performance mods the immediate signal to run away screaming that they are when you find them on cars?
Although, with a dirt bike, it is probably a safe bet that the previous owner thrashed it around.
I don’t know what the rules are in Greece, but around here a RM250 is off-road only. No lights, too noisy. It’ll be fairly peaky in it’s power delivery too; not much down low, then it’ll rip your arm off and compress your eyeballs. Suspension will be fairly harsh at low speeds.
Two strokes are fairly easy to keep running well. It’s easy to pop the head and barrel off to put on new rings. Main thing is the gearbox/clutch. Racers do the full power, no clutch up-shifts which is a bit hard on the dogs eventually. Clutch is feathered in slow/tight going to keep the revs up so instant power is available on exit.
Check the expansion chamber for major dings as this hurts performance. Are the forks straight? Is the frame straight and check it for cracks. Do the shock/forks leak oil? The shock dampening is probably past it’s best. Springs at both ends are probably sagged by now too. What’s the rad like?
If it starts easily from both hot and cold, responds to the throttle and feels “crisp” to the throttle, engine’s probably ok. When the box has warmed, it ought to go into gear without effort, then the clutch needs to engage smoothly without juddering, even at high revs. This ought to mean the clutch plates aren’t warped/worn. Sprocket teeth need to be straight with no “hooks”. Chain needs to fit neatly in the sprocket teeth. If not it means there’s either a new chain on old sprockets or vice versa. Either means things will wear out even faster. Either replace chain and sprockets as a set, or rotate a couple of chains over one set of sprockets to get more life out of the sprockets.
Then there’s the wheel bearings, shock linkages, brakes (pads and disc), and fastener heads (rounded off = dipstick owner).
A MXer from 94 is old school. No longer competitive. Not pleasant for trail riding. Noisy, peaky power delivery, harsh ride. Still fun on a MX track.
Regarding a compression test, as it’s kick start, I don’t know how accurate it would be, or if there are published figures for a normal range. Most owners just change the rings regularly, depending on their use and performance requirements. It varies from before every race day for full on pros, to never.
Thanks for the advice dynamitedave! This bike isn’t road legal in Greece either but I’ll use it mostly for off-roading and short distances around my house. The good thing is that I can have the bike in my garage indefinitely without having to pay road tax or insurance.
What do you think about the price? Is it worth 950€ if it is in fair condition?
Can’t comment on the price not sure whats good or bad in your area.
The fact that it has a weisco piston is not a problem. With these two-strokes running the RPM’s they do frequent piston and ring changes are the norm. When I raced I would change mine out in the middle and end of the season. The Renthal fatbars are just a particular type of handlebar, a replaceable part that is prone to crash damage. You can compression check the engine. Usually an adapter screws into the spark plug hole and you kick it over a few times. Your best bet is to search for bike buying tips online. Good guides will teach you how to feel for bearing looseness and general issues to watch out for and give you an general idea of what to expect from a compression test.
Dog80, can’t say much regarding its worth. Around here, converting to our peso like dollar, I’d consider it a ballpark starting point. Try to lower 20% or so. You got any goon sized friends? Bring them along; if the seller’s a wimpy kid he might accept a low offer if he’s nervous enough:p
As there’s no paperwork, a stolen MX bike is easy to on-sell.
Ultimately, the bike has no value today for it’s intended purpose (MX racing). You need to decide the value it’s worth for your intended purpose.
Dirtbikes these day come with a title same as a car. If not a title you can get a original reciept or a certificate from when it was bought from the dealer.