RK Tek Performance Dirt Bike Head Review KTM 250 and 300 and Yamaha YZ250X

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This little review is something that is long overdue. Today we talk about the RK Tek two stroke performance heads. I’ve used personally used them on 3 different bikes and will be soon trying it out on another. Scott is using it on his Yamaha and loves it.
Bike we have tested them on:
2015 KTM 300 XC
2017 KTM 300 XC
2017 KTM 250 XC
2017 Yamaha YZ250X
I’m going to be trying it on the 2017 KTM 150 XC-W soon. They are $325 at the time of this review.
Special thanks to my $10/month patrons on / dirtbikechannel
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[@arizonarider9120]

Nice review Kyle. I put the RK Tek head on my 2017 KTM 250 XCW and had them grind the insert to improve low end grunt. It was an immediate noticeable improvement. The final improvement was replacing the stock reeds/cage with the V Force 4. I have run the Lectron since new. The combination of all 3 have made this the smoothest 250 I have ever ridden. It pulls very close to a stock 300 up the hills but with better fuel consumption and the free revving characteristics of a 250. It is extremely difficult to stall at low RPM's. This cylinder head is the real deal. Worth the price.

[@bryankeeler2788]

Thanks for posting this insight. As I just asked in another comment, I am wondering if the 250 can be made to have the kind of low-end grunt a stock 300 has, without significantly sacrificing its other virtues (lower rotating mass for better handling and free-revving). Sounds like it can be done.

[@arizonarider9120]

It can be done but if you want the true low end torque, the stock 300 is still better.

[@AustenARW]

Yeah, I've always thought it would be cool to see you ride a "widowmaker" 500 from the 80s. Obviously handling, etc, is not going to compare to today's bikes but it would be fun nonetheless to see you 'review' something from a different era.

[@chrisvozza6530]

Really looking forward to seeing what kinda gains that 150 gets with that head!

[@blacklight4460]

I'd keep an close eye on exhaust temps with that head. Aftermarket heads often assume the rest of the engine is stock. On tricked-out two-stroke, head mods can easily lead to pinging or detonation. On some bikes you can back off the ignition timing a bit, which will allow faster/longer WFO running without holing the piston and will also mellow out low speed jumpiness. Race gas might be needed in some dense-air locations.

[@scottleverton2453]

Instead of running your jetting rich to tame the responce on the low end put a 14 tooth countershaft sprocket on. Now you have enough power to pull the taller gearing. You will like being able to pull second and third gears longer

[@highwayman1218]

Yep 14 50 here. Very happy

[@3tvman5]

Video idea! Find a 02-07 Honda cr250 with mods (oversized front rotor, exhaust, sprockets and flywheel weight, suspension, even RK Tech Head etc) and see if a built older bike could compare to these newer KTM! Love the videos man!

[@norbymunteanu9994]

that was a really well put together product review video answered all my questions

[@callumcr85]

Hey kyle ! love the vids :) when can we expect a final verdict on the 150 xcw ? I'm really debating picking one up though I definitely don't want to be be struggling on those uphill climbs like I do on my 125.

[@dwall8915]

Thanks Bro. Brotherson! So do you still recommend the lectron with a stock head? Love your videos.

[@hhds4716]

I want to see you on a PANTHERA CR500 or kx500 big bore BILLET ENGINE

[@TheDaltonmichaels]

childs toys ! Skip straight to the Maice 700cc two stroke lol.

[@michaelselix8817]

Is that 700 actually a Maico?

[@shawnkeene3370]

Man watching your videos kill me. I just don't have the extra money for a dirtbike. With my buisness ,kids and wife takes all our extra money . I have a 2013 drz 400sm but I want a good dirtbike too and 8000.00 is alot of money right now. I love your videos keep up the good work.

[@tannergray28]

What would be a better bang for my buck, a new RK Tee head or an exhaust system?

[@mitchelbaker6497]

I will be eagerly waiting for your review of the 150 XCW RK Tek Performance Dirt Bike Head. Do you have to run race gas with RK head on the 250?

[@DirtBikeChannel]

No, I am running pump gas 91 octane.

[@TheRealKalEll]

KYLE, you're awesome!!! Keep up the great work!!!

[@highwayman1218]

Kyle, what have you been happy with on inserts with the RK head as a leave in? Do you prefer a compromise of leaving in a lower elevation insert when riding higher. Or do you leave in a higher elevation insert while riding lower elevations. Hard to describe in a message. Im also running a RK head with 2k to 4k insert and Lectron 38 from Slavens. Im usually from 3k to 6k elevation from So Cal desert to mountain usually and figured the 2 k to 4 k insert be best compromise for what I run and not constantly pulling the head to run a different insert. Is there one choice thats been a favorite for you as youre up and down in elevation? I doubt youre constantly pulling and swapping inserts as you change riding elevation. Just curious on your opinion on choice of leaving in inserts for your general riding.

[@spakls103]

Great can't wait for you to review it on the 150 X CW I have that bike now definitely couldn't use more on the lower end and I know there are other manufacturers out that make heads and you tried several so if you can give me feedback as to which manufacturer you think worked better thank you

[@jmgoggy]

Kyle which silencer are you using on the 250xc? Have you had any experience with the qstealth in comparison to the turbine or powercore? I'm basically trying to find the quietest that won't rob low end. Thanks

[@dirtbikesicehockey4788]

Looking forward to the one five o getting a power boost. Hope it has gains down low so you don't have to be on the pipe so much

[@dirtbikesicehockey4788]

MaverickDH I know exactly what your saying. I think my point is going to be missed. I just want to see (both figuratively and literally) the next video. I've ridden the old KDX200s as well as the KTM 200. You're right, they are what they are and that's why I prefer 250 s so I can be "lazy" at times. Sorry, I'm rambling. Just looking forward to next vid because there is no way I could do all the stuff Kyle is doing.

[@Fontainebleauify]

I've always thought these arguments were strange. I'm not sure why someone would want it to be more difficult to ride the same trail? If that's the case, the logical thing to do is to ride the worst bike you can because it's so much harder? Practically speaking, doing all that extra work tires you out and then you can't ride as much. Also, by riding a easier bike, you can do more difficult things. I went from a 200 to a 17'300 with rk tek, it's just so much easier to do the same trails and now I can try more difficult trails. Also, I can ride more often because I tire less. I recently did 5 miles of hell on my 300, it was difficult, but on my 200 it would have been hell and not a lot of fun. Seems obvious to me you should always get the bike that limits you the least. Possibly there's a good argument if you're trying to compete at a high level but for most of us, who cares. For those of you undecided on a 150 or 200 vs 300 or some such similar argument, get the bigger bore, it makes everything easier and therefore more fun.

[@dirtbikesicehockey4788]

I've ridden 250s for the last 30 years and I would not switch for a lesser or bigger bore. It suits me fine. I'm just looking forward to what Kyle is going to do to the 150. I don't have the time or resources to do what he does. One can say I am living vicariously through him.

[@dirtbikesicehockey4788]

amen

[@braident7833]

Love your videos Kyle 👍

[@DavidGarcia-jw1df]

Kyle, I have the ‘18 250 XC-W, non-TPI, and am considering replacing the head for woods/trail riding. What’s the difference between the RK Tech and S3 head,, if you know??? Any advice between the two?

[@DeerKiller011]

I wanna see another RK Tek Head review.

[@grecoconduris6716]

Hey Kyle, would you prefer the 250 with the head over the 300 standard? Or is it still not enough low end?

[@bryankeeler2788]

Yes, I have a similar question. Does the head on the 250 give it as much (or nearly as much) low-end grunt as the stock 300? Could potentially be (nearly) the best of both worlds . . .

[@Fontainebleauify]

275cc low end equivalent I'd say.

[@jameswaggoner7295]

Any noticeable difference from the S3 head?

[@lametraserillos1]

is very similar...

[@equalizer4633]

Still wanna see a comparison between a 2007 250x and 2017, and similair with a 300exc. Will come in handy for those of us who have a lower budget

[@jaysmith7137]

Slavens racing head or the rk tech head any thoughts i have a 17 te300 i know the slaven racing head comes with 2 inserts.

[@Cooldibs]

How did adding the head to the 150 make the low end power feel?

[@smokerace1870]

Race fuel only or can you run pump gas with it, thanks

[@Vini-rm2ss]

VHM cylinder head is verry Good in Europe ! Good vidéo !👏👍👌😉😁!....

[@2wheels4life27]

Just get back from a golf game kyle lol?

[@Yz_768]

The Apex YZ250 head easily outperforms the RK one

[@BlackDirt_Enduro]

Love the apex (xc) on my 250X!

[@dales3897]

I was wondering how do you setup the squish band clearance?

[@jrob160]

Dale S, you cannot change squish without either re-milling the squish band or adding thickness to the base gasket when running an o-ring style head gasket.

[@dales3897]

jrob160 I was wondering how you get the squish band correct without measuring and milling the head or changing base gasket height. Mine was measured and remachined to suit my fuel mix riding style. The place that did that work is always doing brand new heads as the tolerances of new ktm etc can vary wildly.

[@garydauksch]

Where are those trails? They look awesome!

[@kevinjohnoflynn]

Will you be testing the 250tpi soon??

[@trials_bike-xu3xf]

Would something like this be able to add more low end to a 2006 125 sx? And/or lean out the engine some? It runs pretty rich and spits quite a bit of oil out the tail pipe and I've already changed the jetting to lean it out and it is definitely better but could still get better

[@iD4v1d]

You'd be better off getting a bigger bike like a 200/250/300, no mod is going to give the 125cc good bottom end, that's their characteristic.

[@trials_bike-xu3xf]

iD4v1d I figured as much. Just gotta save up my money. Thanks for the info!

[@coryjamesc]

The solution to the 150 not having enough power is Ride a 250 or bigger.. LOL

[@IcemanSam650]

coryjamesc seriously. Not sure why they ditched the 200 but Beta and GasGas both have a 200 now and I'm sure both of those out perform the KTMs.

[@Chris-uh3cm]

Agreed. my 14 KTM 200 is a blessing after trying to handle my YZ250 through singletrack. I wont have anything else other than a 200. KTM screwed up not making them anymore

[@BrodyHenry96]

Does this head affect reliability at all?

[@motoman5304]

Dirt Bike Channel hats??? Coming soon????

[@Kolsch221]

What about TPI, is it different?

[@kennethfarr9921]

No dyno runs,figures,?

[@coxyiv313]

What jetting are you running on the 250xc? I just picked up my 18 250xc yesterday and I have my rk tek head already waiting to go on the bike 👍🏻

[@DirtBikeChannel]

Contact me through my website and I can give you some direction on that.

[@Kyle-pl6rl]

What premix ratio are you running? What kind of oil?

[@moshpitcircles6345]

Amsoil Saber, 80:1

[@hardup9809]

Don't listen to these smucks run it 60to 1 anything less and your asking for it

[@archiebaily5008]

@@hardup9809 does less oil more fuel make it faster??

[@archiebaily5008]

i run 40:1 on motorex for my ktm 200 xcw

[@TruenorthmtGod]

I want more power. Even though I can't use it.

[@HybridEdits]

Love ktms but the only thing i have an issue with is that over the years, they havent made a deal with red bull for graphics besides on the FEs. They look so damn good.

[@georgeboswell4620]

Would you be interested in testing the new STIC metering block; contact [e-mail] Contact Harris Performance for the hottest new product in the industry; there is a new game in town for the Keihin PWK A/S and Mikuni rounds slides; designed and invented by Boswell; performance guaranteed. See the new STIC replacement block with STIC tubes for the Keihin A/S metering block; comes pre-jetted with newly designed gasket; it is a replacement for the original PWK metering block. The new STIC block has a replaceable STIC jet tube available in different sizes. It has shown considerable improvement over the industry competitors. This new STIC Block will add +5 HP to your present set-up; has substantial over-rev and will accelerate from any position. The New Gasket for Keihin A/S is also available from Harris performance. Incidentally, the Keihin A/S STIC will replace the four-stroke carburetor with great performance gains. Is available for the Keihin A/S Shorty; screw top; available for 85cc through 500cc. Specially designed STIC jet tubes are available for all of the Mikuni and Keihin series that use jet tubes. STIC carburetors and STIC tubes are current record holders in the NSSR circuit. New STIC billet cylinders and heads are on the way. For greater detail; Contact sticsupertorque.com.

[@francoferreyra9319]

Does it take away life on the engine?

[@luisbremer9351]

Franco Ferreyra probably does , more compression than stock on a stock cylinder

[@duken4evr]

Perhaps at sea level, but if you ride at elevation a high comp head simply restores some of the pressure lost to elevation. These heads generally cool better too, with bigger passages than stock. Have tons of hours with a higher compression head on my old bike, no notable issues with engine life. I ran my last piston over 200 trail riding hours, it looked great when it came out.

[@convex7456]

DO a vid with a trail ride on cr500af, kx500af, or a good ol ktm 380 ! Everyone would watch! I guarantee brother! A trail set up cr500af will DESTROY ANY KTM525 450 ect.... My buddies had me sore for a week. And it wasnt noticably heavier over my old yz250. TRY ONE ! YOU HAVE THE CONNECTS!

[@skatr186]

.308or5.56? Gig gg. G g

[@tacopro218]

I appreciate these videos, however, without dyno runs comparing stock to your modifications, seat of the pants impressions mean VERY little. Sorry, not trying to sound like a jerk. BTW, I'd gladly send you some money to see some dyno pulls.

[@DirtBikeChannel]

I see your point. Go ahead and send me some money and I'll think about it :) Make sure to send enough for me to take off work from my day job, since this is a side hobby we are talking about. Seat of my pants does tell me whether or not I like mods though. Have a great day brother.

[@tacopro218]

Haha. I'm sure some of us can scrounge up enough cash to make it worth your while. No wait, you can run to the dyno shop on your day off! :)

[@tacopro218]

Oh, and one last thought. I don't understand why elevation would have anything to do with compression and lastly, when installing a high compression head, high octane fuel must be used. I run straight VP 110 in my stock 250x and Montesa and would not run anything else. Maybe fuel would be a good topic for one of your upcoming videos. You can discuss, clear ( non ethanol) vs. ethanol blends and race fuels. Thanks for the content and keep up the good work. Happy trails!

[@jrob160]

Taco Pro, elevation is the most important part of compression. Naturally aspirated engines lose approximately 3% of BHP per 1,000 ft of elevation. Higher compression heads don’t necessarily mean you need to run “race gas” so long as the compression is suitable for the octane of fuel you would like to run at any given elevation. RKT takes elevation and the fuel you would like to run into account when choosing the volume of the combustion chamber he will cut for you.

[@r563]

If you can afford to give away 10k motorcycles you can afford to do a real test .If you were not making any money you would not be doing this .

[@convex7456]

They need to make a 5 speed 300 geared for Moto. I prefer a yz250 powerband for trails. Idk why. Maybe because I grew up on a kdx 220 with alot of low end and my mid life yz was more fun.

[@sl00thy]

ktm makes a 250-300 sx or xc kit

[@bushbasher69]

what a waste of money lol the 300s are all u could ask for, unless you are a top 0.05% rider