Has anyone got a bike for sale under £700? He wants a 250cc Also can anyone give some advice on what to look out for when viewing dirt bikes, or recommend any good models, he has been looking at the RM and YZF. Thanks
Hi Red
Does he want a 4 stroke or 2 stroke? 4 stroke 250’s are quite high maintenance and if they let go you will be looking at a lot of money (£600 plus easy) to repair. I would steer clear of a 4 stroke 250 unless I had about 1500 to 2000 to spend
A 250 2 stroke is a whole lot of bike and unless he is an experienced motocrosser i would steer clear. A 125 2 stroke is really the best way to go, low maintenance, cheap to repair if they break and the best smiles per mile especially if you have about 700 to spend. As for the buying specifics I would research a few buying guides on websites but as a general rule try to find a bike that is maintained a lot by its owner. Motocross bikes require far more maintenance during use than road bikes.
Mx tracks is a good forum if you want more specialist advice:
Hope that helps
Paul.
Much apretiated Paul, my son is experienced and I think a 2 stroke is the answer for him. He is keen to get a Honda CR 250 (I think thats the model) not sure if thats a 2 stroke.
I thought the 2 stroke took alot of looking after, and need reg engine rebuilds, a mate who does alot of green laning swears by 4 stroke as you spend more time on the bike than in the garage…
Interesting debate that Sleeper
In general (not necessarily off road related) four stroke motorcycles are more reliable than two strokes due in part to the fact that a four stroke has an in built lubrication supply where as most two strokes get their lubrication from the oil in the fuel supply.
For example the seized pistons that could be a problem on many 80’s 90’s two strokes such as RD’s, Kr-1S’s etc. didn’t affect the similar capacity FZR400’s and ZXR400’s.
However, in my first answer I was talking about motocross bikes (not enduro or off road) these are bikes that are designed first and foremost for racing and are in a very high state tune. For example, most four stroke motocross bikes from the leading manufacturers are in a higher state of tune off the shelf than their equivalent sports motorcycles. A KX250F runs a higher compression ratio than a ZX-10R and uses both titanium intake and exhaust valves where as the ZX-10R uses just titanium exhaust valves. Weight is also a critical factor in motocross so bikes are paired down to the minimum.
The service schedules for most four stroke motocross bikes (ie any that are competitive) are daunting so most people don’t do all that they should. The problem comes when something goes wrong on a four stroke. Say grit gets into the air intake through an ill fitted or badly maintained air filter, it wears away the coating on the valve seat so that the clearances close up. The valve then eventually gets a heavy hit from the cam (because the valve clearances haven’t been checked - a job that requires a shim kit and some time) snaps and drops into the engine. One completely written off engine and a bill for £1000 at least from your local dealer thank you very much.
Same initial symptom on a 2 stroke 125 or 250 would probably only require a new piston and barrel and could be fitted at home by a semi-competent mechanic for a substantially reduced price!
As for Enduro bikes that you were talking about sleeper, well it really depends on which model you are comparing with which. You would expect something like a four stroke DR-Z to be more reliable than a 2 stroke KTM 125 EXC (just don’t let Foxy ride the DR-Z eh Jay 
) but to some extent it makes a difference how and where they are ridden.
RedZ the motocross bikes are:
CR250, RM250, KX250, YZ250 2 stroke 250cc motocross bikes.
KX250F, CRF250, RM-Z250, YZ250F 4 stroke 250cc motocross bikes.
A CR250 two stroke is a good bike (although the later ones aren’t so good as Honda were the first manufacturer to go four stroke only so stopped developing them first) but it is still a whole lot of bike. Their huge amounts of power can make them very tiring to ride during a 20 minute (club) moto so a lot of people below expert level would be quicker on a 125 or 250 four stroke.
Anyways, hope I haven’t bored you all too much and happy hunting for a good used CR250.
Paul.
Thanks fellas, interesting stuff. He bought a Honda CR 125 in the end, we will pick it up tomorrow.
Best choice for that type of money redZ
I’m sure he’ll have a whole lot of fun, 125’s are so fulfilling to ride as he you really feel like you are riding the thing! Sometimes on a 250 it can feel the other way round.
how often would a cr250 need a new piston, top end then?