250-500cc Stay 250 or go 300?

Hey guys, seemingly simple question. I'm about to get a top end done on my 09 WR-250, $630 for parts and labour. Not bad, but for $1400, I can ride out on a 300 instead.

Bike is almost exclusively used as a street ridden sumo, so can always use more power. In saying that, with DEP exhaust and Lectron its a long way from being slow as it is.

Anyone who's ridden both feel free to let me know your opinion. Anyone who's done the conversion, what are your thoughts after doing the swap? Thanks guys.

That's a lot of coin for either option. Id keep it as a 250 - I like the way the 250 revs up quicker.
If you still want the 300 - if I were you Id be thinking of flipping the 250 and upgrading to a new bike

Yeah it's not cheap, but I'd rather get it done by R&D and know it's done properly. I'd do it myself if I had someone to teach me, but I don't want to screw it up. I love the 250 in the dirt, it's more than powerful enough. On the road but, with the gearing on the bike (15-40 to make it bearable above 60 km/hr) it's a little dull compared to the 15/47 on the dirt wheels.

If it wasn't for having everything else (Lectron, exhaust, wheels, brakes, etc) exactly how I want it, I'd have sold the thing ages ago!

I'd go along with this on the coin side ...

There is no way I can keep my 08 WR250 under control much of the time ... That 300 might allow 4 stroking the 2t to a higher level with all the low-end grunt it brings with it and riding it a gear higher in many places might be the ticket ...

But I'll stay with a 250 and its behavior for now ... a HYDO clutch might help trying to keep these beasts under control because the HYDOs on the new 4t machines are soo easy to control ...

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I'd think about re-sleeving the cylinder to a 300 also if you go that way, if that is possible ...

top ends on two smokers are easy you played with construction blocks as a kid i assume? just the same thing, take pictures every step as it will only take 2-3 hours for experianced guys so save the labour thats gotta be $40 bucks an hour no? and order all the parts through r&d so you still support them.

or return it to std and chop it in for the 300 wont the lectron slip straight in a 300?

Thanks guys, still thinking. I agree that in the dirt the 250 is PLENTY. On the road, you can always use more power & torque. As for trading up, I've spent a year and quite a few bucks building my perfect sumo, once you add up all the parts, it's quite a bit. Also be a nightmare to return to stock, so that's out.

I'll go for a ride on the weekend and have a serious think.

Very nice looking bike. I would leave it a 250 just because I wouldn't think I'd get my money out of the upgrade when it comes time to move on. Makes me consider turning my seldom used 250 into a sm!

A 300 will pull the tall gears much easier.

If I'd do supermoto probably I choice 300,racehead and high rev exhaust

250s seem to be much happier higher in the revs. You could pull higher gears on the 300, but you'd probably have to since it wouldn't rev out as willingly.

...you know if you found a '12 or '13 300, you could move all those parts over to it and put the new plastics over to that one and then you'd have a BLACK frame to go with the rest...eh, eh, am I right?

And what shift lever is that?

so you planning to get the 300 for sm too? yeh 250 off road is ideal but do you take her there at all? if not go for 300 head upgrade.

you bike looks sweet congrats

n.b. my 360 motor looks like it will slip into that frame no worries

Agree here
With threads in the index on fitting 144 and 165 you could do it easily Also you tube
I'd never done it before and now I've done 3 or 4

Get another bike for the street! probably not what you want to hear

Yeah, I've looked for a 360 engine. Found one, missed it and regret it since.

I don't really get a chance to take it in the dirt, but does see the odd fire trail now and then.

I have a mate who is an ex-SBK mechanic, I'm going to give him a call today and ask him if he feels like sharing a carton of beer and some knowledge. I'm not mechanically retarded, just don't really want to do my first without a hand.

As for new bike for the street, I'm hearing you. Turning a 2T enduro bike into a road bike is not the smartest idea anyone has ever had. I'm thinking the opposite but, was looking at an 848 or F3 for the road. Now thinking WR165 for the dirt.

Yeah, top end really won't be difficult -- or expensive to do on there. Piston and rings should come with a wrist pin, add the wrist pin bearing since you've got it apart and it's only a few bucks more, a gasket kit (if you get the Husky full engine kit, it's cheaper, but DOES NOT INCLUDE the 2 o-rings for the head), have coolant and pre-mix oil on hand. A torque wrench is usually good. And not that it looks like you need to, but wash it really well to keep dirt from going in.

If you've got everything in hand before you touch your bike, then you should be able to do the whole thing in a few hours for your first time. After you've done a few 2 stroke top ends, they go much quicker. I once did one on a KTM 200 start to finish and fired up in an just under an hour, but there is no reason to rush, I enjoy working on 2 stroke engines. 4 strokes complicate the heck out of things, and I've dabbled in those, but do not enjoy the thought of it.

I hate to admit to thinking about stripping it down to frame to change frame colour. The shift lever is a cheap RFX one off ebay. Ordered hammerhead off a local dealer (NOT R&D), waited 8 weeks, then gave up on the dealer and bought off the net.