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Great coverage on the TWMX poster!

Check out Spencer Clark in TWMX!


Big Bore 250’s: Great fun with all of the current Fuel Injected 250’s loving a big bore bolted on!

Millennium/Vertex Project KTM 250 Big bore test

2013 JCE Glen Helen 10-Hour team

Finally! A great value wheel set



MXA – Cylinder Works CRF270

REM MX Glen Helen

  REM and Glen Helen do a great job– And Myra is so Awesome!                  Cylinder Works KXF269cc  for the REM Holeshot!      

2013 Big Bore RM-Z270

Here is a fix up project we did with a CR125

MXA: Cylinder Works’ KTM 365 SXF

Dirt Bike Magazine CRF 250R mods


Check out this new video on Racer X with a YZ450 we fixed up.

It’s the most wonderful time of year!

It’s the most wonderful time of year! Yes, especially with a new RMZ250 and a MX11 on some freshly rain-watered  California dirt it is truly amazing.

Here is a link to a great story on a RMZ270 project from Racer X

Here is a good video for those wanting to know how to remove their back-fire screen from their current 4-stroke.

Here is a video we did to help keep your bike looking and working good.

Check out part one on our Dirt Rider project KXF250

Mini Rider CRF150R Project

Dirt Rider’s Two-Stroke bottom end rebuild with Hot Rods, Vertex and Millennium.

2012 YZF250 Project bike follow up.

          JCE racer Cody Brownfield and Jay Clark have now logged over 40 hours on the Dirt Bike Magazine project Yamaha YZ269cc.  Cody is racing REM and Triple Crown events in So Cal. The 2012 model has proven to be very reliable and perform well with all of the mods.  The

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A Great Sight!

      Six new 2013 250’s ready for a Dirt Rider Shootout. And a new Honda 450 for a cover shoot all with new Dunlop MX 51’s ready to go.                  

My favorite boots now come in some blinging color combos.

Raptor 250


Racer X Tested: Install Cams


The Forsaken: A motorcycle is saved


Good Buys and Great Performance

Beyond the 250Fs How do the 250s stack up as 270s

Cylinder Works YFZ478cc Big Bore


Big Bore Vertex RMZ Project Bike

MXA Test: Best Bank For The Buck

RacerX 125

We Ride Cylinder Works KTM 280 SX-F

Click for the full story  

Jay Clark build on the cover of the May issue of Dirt Bike magazine

Click for the full story

Budget Build – 2009 Honda CRF450R

Click for the full story: – After

Racer X Tested: CRF270cc Cylinder Works/Hot Cams/FMF

Best Bang-For-Buck Mods


42-Hour Endurance Bike

  Click for the full story              


  There are some good companies getting into Motocross that have been in the industrial and automotive industries. Well, LOCTITE is a brand I have used all of my life is now a big part of the MX & SX circuit.  They have some great products that you can trust and are readily available. Glad to

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MXA Tested KX269F

Click for the full story

CV4 High Temp Rad caps

  Check out this great MXA Review on the CV4 High Temp Rad caps.

Rebuilding Two-Stroke Top End

  Check out this MXA story on rebuilding your Two-Stroke top end.  Vertex Pistons, Cometic and Millennium Tech made it all happen.

Metaltek Racing Engine Stand

Here is one of the coolest new products in quite sometime. For those that work on their own engines a lot this is a must and worthy of any top notch shop. http://www.metaltekracing.com/ Here are two videos that show all about this great engine stand. Click for more info.     http://www.metaltekracing.com/ Videos that show all about

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YZ250 Refresh


Project Banshee


Jay visits C&L Companies

I was able to go back and visit the main company I work with C&L (Hot Rods, Pivot Works, Hot Cams, Cylinder Works, Vertex and now Ossa) – Boy that is a mouthful to say.  I had a great time and it is amazing how much is always going on there.   There will always be

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Alpinestar Tech 8’s My favorite boots just got a lot better.

AlpineStar Tech 8s   My favorite boots just got a lot better.  The Alpinestar Tech 8’s are now over one pound lighter(less weight hanging out there and potentially less stress on knee).  They have much easier to use buckles, better soles and extra hard plastic on the right boot where you hit the foot-peg when

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Cylinder Works 727 Raptor

Click for the full story.

Thumpity ThumpThump Dirt Bike Magazine WR250

Click for the full Dirt Bike Magazine Story    

A Faster Blaster

Build a Faster Blaster. Click for the story.

MotoSport Builds a Dream Honda 450 Quad

Next great MXA project

FastCore Mods head, port and valve job

Brady at FastCore Mods recently ported my CRF250R head and did a valve job.  Amazing work and the power is great!  Check them out for any head work you might need.  810-441-3172   www.fastcoremods.com

Motocross Action YZF 310

Mail Order Dream Ride

Jay Clark Builds a Mail Order CRF250R for the Pages of Transworld Motocross:

Honda CR125 – Craigslist Killer Project

Check out this Jay Clark Built CR125 Project Bike: Motorcycle USA Story: http://www.motorcycle-usa.com/374/10557/Motorcycle-Article/2003-Honda-CR125—Craigslist-Killer-Project.aspx Motorcycle USA Video: http://www.motorcycle-usa.com/1190/Motorcycle-Video/2003-Honda-CR125-Craigslist-Project.aspx

Check out these new Maintenance and How To Videos:

ATV 4 Wheel Action magazine

Check out this cool little race quad we helped with for a young lady from Riverside. Look for the full test in the next ATV 4 Wheel Action magazine. 

KTM Hot Rods

Hot Rods the Original cranks and Rods now gives you KTM Complete Crankshafts.  KTM owners pleaded and yelled loud enough that we listened and have a full line of complete crankshafts for KTM’s.   The models now in stoke are for the two strokes (125SX, 200XC, 250SX 250, 300MXC) and four stroke (250SX-F 2005-2010). The complete

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Pivot Works Shock Rebuild Kits

For those suspension experts and just all around good mechanics Pivot Works  now has complete shock rebuild kits for the older CR/CRF’s (with Showa shocks).  One complete kit fits an incredible amount of Honda’s; CR 250R (2002-2007), CRF 250R (2004-2009), CRF 450R (2003-2008) and the CRF 450X (2005-2009).   Retail price is only $89.95 so a

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Hot Cams

Hot Cams has long been the standard for drop-in power.  Now there are more options than ever before.  Hot Cams gives you more options and more power than any other cams on the market.  Stage 1 and Stage 2 for simple drop-in power and then Seven different “builder series” cams that are targeted for the

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Uni Filter

I have been using Uni filters for over 20 years now (yes I am old) and they never let me down.  Also they have any crazy size filter you could need.  Here is a pod that we used on a little race quad.  You name it they got it.   Uni Filter www.unifilter.com                       714-535-6933                 

Race Tech

There is no suspension company that is as diverse as Race Tech who works on ATV’s, Street bikes, vintage and of course dirt bikes.  When it comes to something odd-ball they will fix it up.   Here is a TTR Shock that needed help with a shaft they got fixed up.  Race Tech www. racetech.com 951

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    What did I do before MotoSeat? Struggle is the answer. Travis is amazing and custom seat covers and has years of experience. They look and work amazing.     MotoSeat www.motoseat.com 951-258-5229

UTV Action ParaPros Rhino

Raptor 250 Power Package

Millennium Technologies CRF 264 Big Bore

CV4 Honda CRF450R

Check out the cover of the May issue of Dirt Bike magazine for my latest project

Click on the cover for full story Jay Clark Built CRF250X Cover        Check out the video about the Project

Check out this great review on Dirt Rider of the new CRF250R Cylinder Works big bore kit!

Today I got to do a quick 49 minute moto on my favorite practice track in the entire world, Cahuilla Creek Motocross!  Track has been great with the new owners and Ron has been doing a great job on the track prep.  After a rain he has it fixed back up about as fast as

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CRF300 Video Built by Jay Clark for Thumper Racing

Thumper Racing Hot Cams CRF300R Project. Here is a link to one of my latest project bikes


Dirt Bike Magazine three CRF250’s

The new CRF250R’s are fuel injected and a complete new engine. Travis at Thumper got one to 280cc with a big bore and a stroker version out to 300. We did the 264cc version here. Tested one day at racetown and one at Piru and had about eight different test riders all love each of

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2010 CRF450R for PU

Parts Unlimited magazine got to test the best mods on a current CRF450R– Hot Cam and high comp piston. Josh Brown for testing riding and Kenny Jones shooting the pics. Came out great!

MXA Project YZF450

Tom Morgan at Hot Cams came up with great cams and mapping to put this mod on top of MXA’s mini-test a few months back!

Got it this time

Last minute Hot Cams got Kiniry to fly out from New York state and give it a shot and see the Racer X project bike through.

Johnny gave it a great shot!

He came up short the Sunday before the National on a section they ended up taking out for the race. Bummer deal—

FMX Best Whip Champion Honda CRF450R Race Bike

We tried for the last national but go hurt so had to go Johnny Jeldera.

Pivot Works Watertight Wheel Collars

These come in the already proven wheel bearing kits and have an o-ring on the inside diameter of the spacer so that no water gets in to the axle/bearings.

Honda’s Proven TRX 450R with a Cylinder Works Complete Big Bore Kit

A simple drop-in kit that really works!!! Combined with a Hot Cam and FMF pipe.

Honda 700XX Big Bore 4 Wheel Action Magazine Project Quad

Great mod by Travis at Thumper!!!!

TWMX project by CV4, FMF, Hot Cams and CP

Last year we went for the 470 big bore but this year we kept it stock bore and hit a homer with this full CV4 mod.

FMF Got A New FI Harley For Project Bike!

CP made the Custom pistons, Race Tech took care of the suspension and Bennetts Performance put it all together. FMF made custom pipes with self tuning Dynojet power Commander. Will be in Cycle World shortly.

2010 CRF450R Ryno Race bike- Great Project

He is hard on bikes!

Dirt Wheels Thumper Racing Rincon Big Bore

On the cover of the October issue!!

Simply Drop-In 269cc Kit

Here is a picture of the Cylinder Works 269cc kit that works on all 2001-2011 YZ/WR 250’s. This is the best mod for your money on a YZ/WR 250. Only $599.95 Cylinder, piston kit and gaskets!

Cylinder Works and Hot Rods 284cc kit for the YZF 250

Fits all current YZF250’s and either the cylinder big bore kit alone at 269cc or stroker to go to 284cc — This one was for Moto USA

Fast Core Mods CRF469cc

Transworld Motocross just tested the latest beast I created. Fast Core Mods did the head Work, Millennium the big bore cylinder and CP the high compression piston.

Thumper WR250X Big Bore

280cc big bore with a CP Piston, FMF Pipe, Millennium Cylinder plating and Thumper put it all together for Cycle World.

Thumper Racing Knows BIG with the KTM 600

Brian at SRC worked with Thumper Racing to make the fastest thing we have ever riden. Josh in his Fox gear is a Quad pro now!

2010 CRF250R Big Bore into 264cc

Stock is 76.8mm and big bore is out to 79mm making it 264cc and the results are great! Big power gains for low cost in the new CRF250R with no fuel mapping changes.

Dirt Wheels 400 EX into 417cc Bolt on Mods

The Honda 400 motor is proven but can just use a bit of a boost from a cam and piston. Hot Cams and CP took care of that with a FMF pipe.

Dunlop Tire Change 2010 YZF450 with Jay Clark

Check out this cool Motorcycle USA tire change video we just did during shootouts. http://www.motorcycle-usa.com/708/Motorcycle-Video/Dunlop-Tire-Changing-Guide.aspx We had a great time making it and I hope you find it useful.

Dirt Bike YZ284cc Vertex and Cylinder Works

Adam Booth from Dirt Bike came out to C&L in Iowa to see the plant and ride the Tom Morgan modified 2010 YZ250 into a 284cc

BBR Has A Great 150 Kit For The Very Fun To Ride TTR125

150cc kit with a Hot Cam and FMF pipe rips and will soon be in Cycle News.

Yamaha Blaster Two-Stroke

The same for nearly 20 years the Blaster can use some extra power and Dirt Wheels will have this quad in very soon.