Two-stroke tuning secrets: KTM powervalve set-up

Автокөліктер мен көлік құралдары

If you have a KTM or Husqvarna 250 two-stroke, then altering the power delivery is as simple as changing the powervalve spring and setting it up right. But which spring do you choose and what difference does the adjuster make?
MotoHead's chief tester Dave Willet runs through the different options and why one particular spring is not advised!

Пікірлер: 39

  • @PhilipBurton-dn3ce
    @PhilipBurton-dn3ce5 ай бұрын

    Short, sweet, straight to the point and I learned something, cheers mate 🇦🇺

  • @Z.Islander
    @Z.Islander3 жыл бұрын

    Brilliantly explained and nice riding style! Thanks for the video

  • @AndrewBoundy
    @AndrewBoundy3 жыл бұрын

    Thank goodness - a sensible video on PV's - thanks!

  • @elmetzicano1720
    @elmetzicano17204 жыл бұрын

    This is the beast moto channel on KZread. 💯

  • @avigaray
    @avigaray5 жыл бұрын

    Great video. Very useful

  • @jeffcornelison888
    @jeffcornelison8882 жыл бұрын

    Great video!

  • @sheldon193
    @sheldon1934 жыл бұрын

    JD aftermarket shim behind the red spring 1 1/2 turns in , power Band smooth with out the abrupt power curve

  • @tracky396
    @tracky3963 ай бұрын

    Good video. Trying to tame my insane old 300 down will try green

  • @wyattlarson1104
    @wyattlarson11042 жыл бұрын

    I’ve got a 2017 sx 250 and I absolutely love the red spring

  • @jannep6772

    @jannep6772

    11 ай бұрын

    I have a 2018 Husky TC 250 and I also have the red spring and power valve adjuster flush with the cover. My bike feels aggressive and I really like it. It has also better breathing modified stock airbox, modified Mikuni 38 carburetor, Boyesen Rad Valve intake/reeds, Wiseco 1-ring piston, cylinder is raised a bit (by thicker base gaskets) to get slightly more exhaust port and trasfer ports timing. Piston top to cylinder head squish band has been set for tighter but still safe clearance to improve burning speed. Transfer port channels have some small modifications but the ports are stock. Cylinder head is from 2017 TC 250 (similar than 2018 is) and it’s milled down -0.4 mm to increase a bit the compression ratio. It has also FMF Fatty pipe and Pro Circuit R304 shorty muffler. This bike has incredibly strong midrange and revs very high too (at least for a 250 two stroke). I don’t need a 500 two stroke as this 250 I have has as much power as I need or even a bit more... 😃

  • @frankyvaque5276
    @frankyvaque52762 жыл бұрын

    Hello good video ! What is your jet setting for 250 sx ? Thx

  • @billyhaigh3659
    @billyhaigh36593 жыл бұрын

    Does anyone know what bars he’s running, 997?

  • @disturbed8999
    @disturbed89994 жыл бұрын

    Where are the graphics from?

  • @idrissalam
    @idrissalam5 жыл бұрын

    Hi, you said you are at 1.5 turn, but do you know the stock setting number of turns? And are you running the green spring with the 1.5 turn on 300 or 250? Thanks.

  • @SWATTracing

    @SWATTracing

    3 жыл бұрын

    Says he's running standard (yellow)

  • @joshhannah6021
    @joshhannah60215 жыл бұрын

    What gearing did you guys end up running?

  • @xombifpv7528
    @xombifpv75282 ай бұрын

    Thank you

  • @kevinvansteenbergen747
    @kevinvansteenbergen7473 жыл бұрын

    Where can i find those graphics ??

  • @deanwcampbell
    @deanwcampbell5 жыл бұрын

    Thanks for the video! Although, it would have been helpful to have shown a torque curve comparison graph.

  • @crazybob1954mo

    @crazybob1954mo

    2 жыл бұрын

    @nyyght7 Uhh Do You Gots one???? ??

  • @david92xj
    @david92xj3 жыл бұрын

    I've yet to have a chance to ride one of these newer ktm 2 strokes, I have always been a 4 stroke guy, but like the idea of the luggability of the 2 strokes and the lightness of the bikes. Does the green spring give it a linear feel like a 4 stroke, or is it still definitely a 2stroke

  • @scottkonijn

    @scottkonijn

    3 жыл бұрын

    Green sucks... i drive red but i turn in the powervalve a lot more. Now my 300 rides like a 4-stroke. More torque and NO massive 2t hit.

  • @david92xj

    @david92xj

    3 жыл бұрын

    @@scottkonijn tpi?

  • @scottkonijn

    @scottkonijn

    3 жыл бұрын

    Yes... a husqvarna te 300i 2020. The spring allows when the powervalve opens @ 3/6/9000rpm +-. And the screw determines how far the power valve opens.

  • @russellbizzell2516

    @russellbizzell2516

    2 жыл бұрын

    Word of advice if you find an older one that's in condition rude that instead 😉😅

  • @crazybob1954mo

    @crazybob1954mo

    2 жыл бұрын

    @@scottkonijn Sorry, You are wrong... The screw adjustment preload on none color preload spring determines at what rpm the PV first begins to open. The colored auxiliary spring determines how quickly the PV opens from partial open to fully open. The PV will fully open at top rpm on either of the springs. The PV full open limit is Not affected by the screw.

  • @sx150rider5
    @sx150rider55 жыл бұрын

    What spring would you recommend for the 150?

  • @dalibortrkulja9582

    @dalibortrkulja9582

    4 жыл бұрын

    purple one

  • @meduza1969
    @meduza19695 жыл бұрын

    completle flush is it the same as all the way out ?

  • @Freaki91

    @Freaki91

    4 жыл бұрын

    Yes

  • @Mrrs6580
    @Mrrs65802 жыл бұрын

    you use 999 bar?

  • @kevinbenitez9924
    @kevinbenitez99243 жыл бұрын

    What model Ktm?

  • @loadthebowl
    @loadthebowl3 жыл бұрын

    why you run dep tho

  • @64maxpower
    @64maxpower4 жыл бұрын

    You can haul on that 250

  • @jakehoskins9669
    @jakehoskins96693 жыл бұрын

    FOR THE PEOPLE WHO’S FINGER SLIPPED AND THEY ACCIDENTALLY BOUGHT A WEAK ASS BABY BIKE (250-300 XC-W/EXC/TE): KTM’s “enduro” bikes are just the xc/sx bikes with a hell of a lot less hp, but you probably already noticed how sluggish your bike is so you don’t need to know the details. These are all of the mods you need to make your motor run right: 1) sx head and cdi. This alone will give around 8 hp boost, which is a butt load for how much it costs, and if you can only afford one then get the head. Buy them from rocky mountain atv [Just find the stock parts from the ktm 250sx] and if you have a 300 then buy the cdi from slavens racing [ lowered rev limit for 300 piston ]. Then power gains are immense and it boosts across the entire rev range. More bottom and top but especially mid range. Also makes to bike tractor even easier through tough stuff. 2) pipe and reeds, they aren’t going to give you a huge boost on the dyno, but the reeds give some throttle response and top end and the pipe broadens the powerband. 3) Carb settings [obviously doesn’t apply to tpi bike] cheapest is to try jetting it, but the mikunies are terrible and it is really difficult. Still on the cheap side would be a jd jetting kit which helped my bike a little, but the optimal way is to swap to a lectron or smartcarb. Lectrons are supposed to come tuned from the shop but I had to adjust mine a good bit to get it running right, and I don’t have any experience with a SmartCarb but I assume it is similar. Whatever you decide to do just make sure the motor isn’t too rich because that makes it load up and bog out. 4) power valve settings. The guy in the video is really knowledgeable and I’m sure his recommendations are good for the sx bike, but the pv settings are completely different in the enduro bikes. Mess with the settings and use whatever feels best, but for those who want the most out of their bike use the red auxiliary spring and turn the brass screw 2 turns in from all the way out. This will make the bike have the most mid to top without losing any bottom. There is an entire ThumperTalk thread on this, but the conclusion is that those settings are most powerful and snappy overall. Good luck with anything you decide to try and happy riding!

  • @themoonissquare323
    @themoonissquare3234 жыл бұрын

    "Power valves" are bullshitted about too much, they are exhaust port blockers, the cylinder and pipe is designed around the exhaust port not being restricted. I've tried finger controlled "power valves" on RGV250 road bikes, a RM250 MX and a Yamaha GP1200R jetski . The Jetski wants the valves open for everything other than when you're cruising home exhausted at 3500 rpm, it makes a slightly smoother exhaust note. For the RGV250's it was absolutely awesome, the valves wanted to begin to open at 8500 and by 9000 they were fully open, it took five minutes to get the hang of pulling them on, it became second nature, you could even feel the lever would start to go light just near 8500....you could even force the valves to shut under hard braking or put on more return spring tension, they were awesome, i'd be dead if still riding them. For the RM 250, just like this bike, i knew the finger lever (just a stubby second clutch lever using the same but longer pivot bolt) would be too hard to control but it was purely for the experiment. The valve may as well be open, a top rider on a fast track shouldn't realize the power valve was stuck open, my tip would be the better you are with the lightest spring the better you must be flogging it, you are just delaying they pipe coming on song. I could ride the RM with the valves stuck shut and it worked as expected down low but could still kill you, if you rode with them stuck open it was a bit of a dog down low but quickly turned insane. The rev range of the RM to RGV is basically half, the RGV needed to be ridden in traffic and twisties, so that's why the were vital, for this bike, the lighter spring is proving the engine is ready to transition to it's pipe designed rev range, it is just basically making the engine de-tuned for a while until the rider is ready. As this video describes, there are just too many variables between rider, bike and track to ever try to make definitive statements about where they "should open". MX power vales are designed to "blow" the valve open, just before the engine needs it, that's why adding the resistance of the spring can give absolute perfect tuning to a riders preference.

  • @hoptard

    @hoptard

    4 жыл бұрын

    Raise the base gasket to 1.25mm with head mod, solves the exhaust port situation. Talk to Kelsey at RK Tek

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