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Hoobz904

Dave's Ktm250 Sx To 300 Sx-W Build Thread.

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I may as well document my SX conversion in a thread. It may be of interest to some on the internet thoughout the passage of time.

I'll keep it as brief as I can.

This will show pics and notes on my conversion of a new KTM250 SX close ratio 5 speed MX bike into a 300 cc 6 speed wide ratio machine.

Some have asked why don't you just get a 300 EXC. Well, put simply, they just don't get it. Hopefully after reading this thread they might see why. On the other hand a lot of dirt biking enthusiasts see what I'm doing and think it's going to be one awesome bit of machinery. A brilliant and exciting way to go.

The main reasons I went with this platform is:

It's the lightest KTM with is sort of mumbo.

I wanted a smoker.

The SX has closed chamber forks.

The SX has a linkage.

The frame is brilliant.

It's a very simple bike.

I want minimalistic electrics and accessories. I don't want any of that crap on the bike at all. Just the ignition circuit is all I need.

All up this project is going to cost me about 2 grand 'LESS' than an EXC!!!

Rec reg is fine by me. I'm going to take advantage of this awesome legality to the max.

The first pics as it sits in the garage right now, with all the stuff I've got for it.

P1500421.jpg

P1500425.jpg

In the pics is:

The 13' SX.

All the parts for the 300 kit. Inc barrel, piston, head, CDI, power valve stuff etc.

All the transmission parts for 6 speed wide ratio.

Full KTM Powerparts FMF exhaust system.

Ego hand guards.

KTM headlight.

Different front and rear ratio sprockets and x-ring chain.

New KTM stand :)

Tool kit.

KTM promo stuff and bag.

Frame savers and heat shield.

I'm putting a Clake on it too, but after I have ridden it a few times. It's not a good idea to do it just yet because there will be some fellas wanting to have a go on it, and putting a Clake on it will only lead to crashes with some riders not knowing how to use a Clake. Lol. Nope not yet. I can't wait to put it on, but it's a wisdom move to delay it a few weeks.

I'm sending the suspension over to Chads, but again, I got talked into at least riding it once before I do that. Just to compare and feel what it's like straight from the factory. It is the SX after all. Brilliant suspenders and handling already.

I'll update this thread every few days.

Oh, and yep, the number has been chosen.

902 it is.

904 being the 4 stroker motard next to it. I still really really love getting out on that baby.

902 being the buzz bomb 2 stroke dirter. Thanks to PaulB for thinking up that one.

Hey, in about a week...

I'm goin' a nangin'.

Can't wait.

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Good Stuff Hoobz's !!!

Been waiting for this one to start ..

Think it will be full of information and going to be one very informative KTM build :):)

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Must be time to hand over that motard hoobz.. PM to arrange a time of pickup or delivery :P Why someone pulls down a brand spanker is out of my mind id ride it a bit first hahaha

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Oh, how silly of me.

Massive thanks to Tim and the people at Mototech KTM here in Geelong. They have been brilliant to me and helped out heaps. Tim was bummed about getting the delivery time out of whack and even understood if I got it from somewhere else. But I like them in there and am pleased to support them, being locals and all.

http://mototech.com.au/

They put the Powerparts high seat on it for me too.

I'm in the shed now, about to remove the engine. Start the stop watches now :)

Good Stuff Hoobz's !!!

Been waiting for this one to start ..

Think it will be full of information and going to be one very informative KTM build :):)

Good to hear. Stay tuned Dazza.

Such a great looking bike!!!!!

This is gonna be a great thread

Enjoy!!! :) :)

I'm pumped. It's a very sexy bike.

I was very tempted to take it for a quick naughty blat down Anglesea, but alas I resisted. It was a massive urge too. Haha.

Nice mate!did u concider the 300xc?its got all the stuff u want on it already!

Yes, I considered everything. The XC-W (wide ratio) would've been the most similar. The XC is 7 kg's heavier, and has electric start, plus it was kind of sketchy getting one here in Oz. The XC is EXC engine based too. It had to be as SX as possible this time. I'm still thinking about the bigger EXC tank that you pointed out fits.

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Must be time to hand over that motard hoobz.. PM to arrange a time of pickup or delivery :P Why someone pulls down a brand spanker is out of my mind id ride it a bit first hahaha

Haha. It's sooooo fun hitting suburbia on that thing. Totally pyscho.

Some have said I have a very nice combo on the shed now. I'm content for now.

Nice warm day, after work, for a quick blat, or high country/desert riding after converting back to dirt guise = 530 Motard

Dirt = SX.

Good stuff Hoobz - will be watching this with interest!

I wasn't gunna even start it. But my missus wanted to hear it, so...

...ahhhhhh that awesome smell of 2 stroke :)

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Without a doubt Kato's are easy to work on.

I timed it. From first tool to touch it, to engine on bench and quick tidy up of work area = 18 minutes. Very easy to work on.

The only slight issue thus far has been the radiator shroud bolt spacers hold onto the bolts a bit too snug, and they spin instead of the bolts coming out easy.

P1500428.jpg

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It takes longer dicking around on the net, whacking up these pics and replying, than the actual work.

The next update will be more exciting.

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+1 that was too quick haha

Im talking about him ripping out a brand spanker to pull apart and *rebuild* LOL Still cant get my head around it.. hahaha Crazy man i would of thrashed the f**k outa it first at least once just cause i can.

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Im talking about him ripping out a brand spanker to pull apart and *rebuild* LOL Still cant get my head around it.. hahaha Crazy man i would of thrashed the f**k outa it first at least once just cause i can.

Haha, yeah we know what you mean, but I don't really wanna ride it while it's unreg, and I can't get it rego before Monday at the very soonest anyway. A few more days won't hurt me. Hopefully ready to legally rip by next weekend.

Besides, I couldn't just take it for a quick fang. It'd turn into too much fun, I'd be out there for hours. It's raining down this way. it's been raining a lot actually, so that means mud, and tonnes of it.

I'm having a lot of fun pulling a part a very clean and spotless new bike. It's the best way to go.

Good to see you're not wasting any time Hoobz. Is she gonna be up for Starglen?

I just came inside to change out of my good clothes while the air compressor boosts up the rattle gun, ready to undo the main tight buggers on the crank etc. I'm starting to get oil on me now.

Starglen it shall be at for sure. Well, that's the plan anyway. Remember I'm just a dumb chippy...and an important and expensive rare part could be busted at any moment :blush2:

There is the very real potential of this thread being turned into a very humourous one at any moment. It could make me infamous as the fuggerer of a brand new bike at any moment.

Hahahahahahaha.

hahaha

ha

:lol:

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Shit has got real now.

I was too tight to buy a new gasket. so I surgically pared it apart with the back of the blade. I didn't use the sharp edge, that would be too carpentry style :)

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I just come in for some tea and a quick update.

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Can you Post a pic of you Lifting the bike with no engine :)

I'll think about it...

+1 get it on ypur shoulder Hoobz. :)

sent from my Galaxy Note from under the stairs.

I'll think about it some more...

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This is hilarious, I spend more time looking for my tools and twice as long looking at my manual than it took you to rip the heart out of your new beast! Congrats on your new weapon, it looks tops. But as I look down the shed photo, what year and model is that sexy old honda???

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The XR is an 83' 200 Noodles.

Houston we have a problem. Dammit. I would have had it back in by now.

It was going great guns.

Stripped out the old 5 speed bits.

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Assembled the main shaft.

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Then the counter shaft

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A picture comparing the two sets of gears. You can see the differences. 5 speed in front, 6 speed in rear.

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Shlapped it all back together.

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Cases reunite and the gears work. I tested them by spinning the counter shaft sprocket and shifting the gear lever. Excellent. 6 gears? Yes.

P1500456.jpg

But then drama unfolded. If you look at the clutch splines on the two different shafts...the clutch splines and end of the shaft are totally not a match.

P1500457.jpg

I've just spent a couple of hours working out what parts match. It's been a bit of a night mare to work out, but it looks like 'all' I need is last year's total clutch assembly. Yep everything, clutch hubs, plates, pressure plate, springs, push rod and pressure parts on the end of the push shaft.

Oooo. Unreal. I'm going to bed.

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