YZ250 Woods Bike

[vortexman]

Yesterday I was challenged with a technical question and it really put the zap on my head. Of course the vacuous chamber that occupies the small space between my ears fills up rather quickly.

What is the best way to build up a YZ 250 woods bike (enduro single track). I am looking for input on the best year of bike to start with and need a bit of direction with regard to flywheel weights and carb selection.

Clarke if you are reading this I blame you for putting this idea in my head. Misses Vortex is still a bit upset about me turning the kitchen table into a dirtbike rebuilding engine shop.

But that KDX 220 was a showroom restoration and well worth it.

 

[hooter]

Buy a 2016 YZ250X?

 

[vortexman]

Buy a 2016 YZ250X?

I guess you missed the query but thank you for the advice. Drop 9 large on a new dirt bike, that would cause Misses Vortex to sound general quarters. It only takes me 40 hours to completely rebuild engine and chassis of any Japanese built dirt bike so in my case I do not pay for shop labour rates aside from machining and parts.

 

[hooter]

OK I was being a bit of a smart ass, sorry about that. However, there is a LOT of good feedback on the 250X online, so it might make a good model for the changes you could consider on the non-X version. You will want a flywheel weight for sure. You could try a "gnarly torque" expansion chamber and retarding the spark timing a little, but other than that I don't know how you could tame the MX power curve without major porting changes; probably not worthwhile based on the cost involved.

 

[KTM-Bryon]

18" rear wheel

RB modified head. see http://www.rb-designs.com/rb_designs_llc_025.htm This made a huge improvement on how the bike ran.

Boyesen V-Force Reeds

FMF Gnarly Pipe

Lectron Carb - http://www.lectronfuelsystems.com/carburetor

Rekluse EXP clutch. I couldn't keep it from stalling without the Rekluse.

That's a good bike now. Pulls hard bottom to top and it doesn't hit hard, just smooth power. I didn't put a flywheel on it but was considering a 9oz. I had a 12oz or so but it was too much. Also a bunch of suspension updates like YZ450 triple clamps & forks really gets it turning a lot better. Of course you can buy just a triple clamp for the YZ250 but those are more expansive than used YZ450 parts. Then you can go with YZ450 rear swingarm & linkage. Ya, there is a long list.

I did everything except the rear swingarm. It was a nice fun bike.

 

[C4cycle]

Oh dear, what have I unleashed! Here, watching intently...I have my 2 cents on the matter as well, having looked into it (gotta run just now, will throw that in soon).

 

[C4cycle]

18" rear wheel

RB modified head. see http://www.rb-designs.com/rb_designs_llc_025.htm This made a huge improvement on how the bike ran.

Boyesen V-Force Reeds

FMF Gnarly Pipe

Lectron Carb - http://www.lectronfuelsystems.com/carburetor

Rekluse EXP clutch. I couldn't keep it from stalling without the Rekluse.

That's a good bike now. Pulls hard bottom to top and it doesn't hit hard, just smooth power. I didn't put a flywheel on it but was considering a 9oz. I had a 12oz or so but it was too much. Also a bunch of suspension updates like YZ450 triple clamps & forks really gets it turning a lot better. Of course you can buy just a triple clamp for the YZ250 but those are more expansive than used YZ450 parts. Then you can go with YZ450 rear swingarm & linkage. Ya, there is a long list.

I did everything except the rear swingarm. It was a nice fun bike.

So basically, ya, what he said. Minus the head and Lectron (not that it's a bad idea, but for me just too spendy). Also, the best year would be 2006 because the suspension upgrade for that year is worth it, but otherwise 2001 - up.

 

[hooter]

<devils-advocate-mode=on>
So, I get the point that you might want to mod a YZ you already have, the optics are definitely easier to sell to the missus, and that alone could be a deal breaker.

But look at the time and money involved in the mods... wouldn't it be cheaper to just sell the YZ and buy a YZ250X? For sure it would be a lot less work. And how does the bike you end up with compare with the factory YZ250X? EG: You still have the close-ratio transmission vs the wide(r) ratios in the X model.
<devils-advocate-mode=off>

 

[cactusreid]

or you could buy a ready made bush bike? new or used the ktm xc-w, gasgas ec 200-250-300, beta ,sherco etc are all good choices?? new or used they will be light years better than a mx bike will ever be in the bush, in my humble opinion. you can change everything on a mx bike , within financial reason and stiil never get close to what a true/enduro bike can and will do for your enjoyment and ability to have a fast/fun day out with your buddies. And most of them have the magical e-start button as well?

 

[vortexman]

Clarke may day, may day, may day. Not to upset anyone but I have an aversion to a company who lets customers complete the R&D on a product so orange is out. As far as the exotics I am not into waiting for parts or spending countless hour calling or e mailing, been there already.

If you fixed machines everyday for a living you would want a low cost low maintenance machine. Oh I also refuse to buy oil cooked by pixies on the planet Venus then told one of these bikes must have it fresh every 8 hours at a cost of double digits per litre.

My buddies do not care what I ride they just wish my mouth would stop running from time to time.

But thank you for the suggestion.

 

[vortexman]

That is quite ok from one smart "A" to another. I was an amateur SA until I went pro in 86. Back to bikes. Must be a two stroke, must be able to order any part online and have it in 10 days, must use oil sold in any Canadian Tire or Walmart and above all must be cheap.

My biggest problem is that I grew up building bikes and having a great deal of fun using my skills and help from friends. Any wanker can go down and drop $$ on the latest and greatest bike but where is the fun in that, or the soul for that matter.

I guess we can put the woods bike idea to bed and if one of you would like to accompany me to the Goddess of motorcycles and co sign a loan for $13 000.00 I am off Monday. I will even buy you coffee.

 

[C4cycle]

It all comes down to "fun at what cost?". I would also rather not spend 5 digit amounts of cash on a toy-only bike. Many would. Like i said, my money is on an '06 or newer YZ. Many have made woods bikes out of them with much success. We're not talking race bikes here, just fun. Tractable power is achievable.

 

[vortexman]

It all comes down to "fun at what cost?". I would also rather not spend 5 digit amounts of cash on a toy-only bike. Many would. Like i said, my money is on an '06 or newer YZ. Many have made woods bikes out of them with much success. We're not talking race bikes here, just fun. Tractable power is achievable.

Good morning Clarke and DSBC'ers and the 351 crowd,In all fairness you did start this. The good thing is that it does generate dialog as well as showcase new technology and ideas. Your Harrison East recon request will be carried out this weekend.

There is snow at higher levels but the mission is also to check road conditions for resource purposes. More on that towards Friday. I do get that question often "how bad is the rough spot?"

This depends on a few things and anyone reading this who is hesitant and does not want to jeopardize bike or limb on the route no problem just turn around, I have done this many times and without shame I must say.

If I take people out there are always safe or conservative options and I think this is overshadowed at times. With luck we will have some good weather and be joking about all this during a break on some logging road in the weeks to come.

 

[vortexman]

It all comes down to "fun at what cost?". I would also rather not spend 5 digit amounts of cash on a toy-only bike. Many would. Like i said, my money is on an '06 or newer YZ. Many have made woods bikes out of them with much success. We're not talking race bikes here, just fun. Tractable power is achievable.

Turning the Yamaha YZ250 motocrosser into an off-road bike isn’t difficult. In fact, it’s been common practice in the off-road world for years now. Off-road trail riders and racers have simply been adding an 18-inch rear wheel, aftermarket exhaust, flywheel weight and skid plate, as well as tweak the already excellent KYB suspension. Modified YZ250s have been a great option for those who didn’t want to ride an orange off-road bike. Now Yamaha offers the 2016 YZ250X for $7390, a mere $100 more than the YZ250 it’s based off and, perhaps more importantly, $1309 less than a KTM 250 XC.