250-500cc Is it possible to convert a 2012 WR250 to 300cc?

Is it possible to convert a 2012 WR250 to 300cc?

I'm talking a "big bore kit," or something along those lines. I'm not talking about a complete engine swap.

If it is possible, who makes the best kits?

Would I need to change the carburetor too? The objective is to "do the job right." I say this because it might be adequate to us the 250 carb, but it might not be the optimal choice.

How about power and bottom-end torque increases? I'm sure I will notice the difference, but will it be a night and day difference?

Is my 250 engine the same as the 300 engine? In other words, once I have converted my engine to 300cc, will it be the same engine as what's in the factory 300cc bikes?

I am not a racer. It's just fun to change things up once in awhile, but not all ideas are good ideas. This idea might not even be possible.

Any and all input is welcomed.

the 300 started out as a kit and evolved into a model

Sell the 2012 an get a husaberg 300 you wont look back

Its possible.
After a fast googlesearch. http://www.ktm-parts.com/8000H0915-p-HUSQEE,HUSQENG.html#.VHM5AcnyCUk

Why get a husaberg 300? Better engine?

Nordman, so that's the one. I saw that one too. I guess part of my post is to check that kit against what you all know. Thanks for your reply. Thanks for helping me.

Do you think it's worth the trouble/expense? But then that's probably not easy for you to answer. For example, perhaps I'm a tinkerer, and it's easy for me to spend $1500 - $2000, on this mod, then why not, right?

But if we were to pursue some sort of objective "bang for your buck," something is telling me that it's not worth it.

Another factor is that I'm close to rebuilding the top-end anyway. So these dollars would offset the cost of going to a 300.

Thanks for the chat everybody.

Send your cylinder to any numbers of competent machinists (I personally use Powerseal for machine and nikasil work) and have the cylinder, head and power valves cut for the bigger piston. i had this done to a YZ250 back in 2008 and that bike is still making arms sore. Powerseal charged like $200-250 and the piston kit was another $200, so I had a hi-po big bore for less than $500 and could have had it ported any way I wanted.

PC, nice! I was wondering if a bore out was possible. So stay with the same carb? I'm assuming that's what you did on your YZ.

Also, what about the pipe? Should I be changing the pipe? If yes, who would you consider? FMF?

Also, I'm gathering from your comment that the power increase is significant. That's pretty cool! Thanks for the input.

Your after a 300 i can see if your needing top end rebuild this is a good way to go, personally i would save the 500-1000 and sell husky just buy a 300 outright doesnt have to be berg, they are brilliant platform and very well set up as stock.
Plus theyre now obsolete so ticks the rare box for me.

Juicypips, what you are saying about selling the 250 and buying a 300 makes sense to me too. Your profile says that you are in Gloucestershire. I've never been there. I'm in the Los Angeles area of the US. What's the used Husky market like in the UK? - and I guess I'm curious about all of Europe too, if that's easy for you to access. In the US a late (2010-2013) WR300's and WR250's too, are rare. There are zero on the market near me, and only a couple on the market in the entire US.

If you were to look for a used bike in the UK (or all of Europe), how would you go about it? Are there any popular online listings in the UK, for bikes? In the US, I'd say CraigsList is our number one market place. This is for private seller to private seller. Of course there are the dealers. As you know, most dealers prefer to sell you a new bike, but a few of the US dealers will sell used bikes as well.

Also, I'm curious as to where you ride in the UK. Are there hills and/or mountains there with rugged dirt roads and single tracks? This question is out of conversational curiosity only. Engage it as much, or as little, as you like.

I did not change the carb nor the pipe on the YZ250 and it worked great. Mine had big compression, so it was a monster down low and into the mid. I retarded the timing 1.5 deg. and put a 15T sprocket on to tame it down.

I also had a 09' Wr300 for quite a few years. Great bike bone stock, but I couldn't leave it alone. Swapped the Mikuni for a PWK, stock exhaust for a Pro Circuit platinum/sparky silencer and even tried a gas-gas 300 piston (domed for more compression), but it honestly seemed to work best as delivered from the factory....besides the finicky Mikuni carb. If I were to come across another WR300 I would install a Lectron carb and be done with it. The motor is already crazy good as delivered, IMO.

And I'm pretty sure there is no difference between a 300 and 250 pipe. When I bought my Pro Circuit pipe I called them and was advised they do not make different pipes for the bikes. It was the same p/n for both the 250 and 300.

If you decide to go through with this let me know and I'll cut you a deal on a OEM 300 piston kit. I bought it, forgot about it and then sold the bike.

Used bikes well we have craigs list here but thats not taken off asmuch as eBay has, used 2008 husky 250 around £1800- 2500 http://pages.ebay.com/link/?nav=item.view&alt=web&id=331290864079 depending on condition and buyers, a husaberg 300 http://pages.ebay.com/link/?nav=item.view&alt=web&id=231387527664 i know a bit apples n oranges but you get the point i was trying to make, i use another site called gumtree for sourcing bikes and good ol word o mouth.

Ridings harder we have tracks and races more than freedom of miles of unspoilt areas to go and loose ourself in exploring, sad really. That said there are a few green lanes winding through the country these are unregisterd roads ranging from single track to full on road width but are often hard to find even with ordenance survey maps.
As for hills im not too far from the welsh vallys so terrain is vairied nowhere here has anything as high or as long as the usa but thats why there are extreme enduros that are well attended
View: http://youtu.be/_7jk6-_9BpQ


I ride in tight woods as thats what i brought myself up on mtb's so feel at home with trees.

My understanding is the same stroke so the pipe should be the same.

A WR300 has the head protruding down into the recessed 300 bore by a lip. Was there a problem with the larger bore in the 250 barrel causing issues hence the lip? Various companies boring out the 250 barrel to what success I don't know.

i dont know about rare, i live in western pa and there are always a few around for sale.

Justin, I can find only one or two in your area too, right now. You are right in the sense that they are not truly rare. Truly rare would be that they don't show up on Craigslist, CycleTrader, or ebay at all. Something such as an early sixties Husky. I honestly think that I could compile a total of five WR300's available throughout the entire US right now. But even late YZ250's are not easy to find. 4-strokes have been the the bike to have, for the past 10 years. Plus, for me to go from the Los Angeles area to say, PA, to buy a bike, would add $1500 - $2000 to the price of the bike. I would need to fly out to inspect and close the deal, then crate and ship the bike. I guess if it was a plated bike, I could take an adventure ride back.

I met a guy from Argentina this summer, in a remote spot along the Colorado River, in Arizona. He had two spare tires tied to his saddlebags. He rode up from Argentina, went to Alaska, and was now on his way home. I wish I took a picture. Now that's an adventure ride! Considering this ride makes a coast to coast ride look easy! I think he was on a Beamer.

took me awhile to find my 95 360, but if you look for a bit its surprising what you find. remember the 360 will bolt right in your bike as well, very similiar, just different power valve

theres a 300 kit in the classifieds here for a reasonable price.

I sent my 250cc cylinder to forward motion and it returned a 295cc for about $600.00.

Just came across this on the forum and thought it may be of interest.
http://www.cafehusky.com/threads/husqvarna-wr-300-kit.51882/