" The Performance Specialists since 1990"
DYNO CHARTS for some of our motor kits.
CRF230L Pipes and motor parts instock Go big Go 250cc.
ENGINES ONLY 1870 Stone Ave. San Jose CA 95125
If you may have a question please e-mail or phone us.      enginesonly@yahoo.com  (408)275-6300 phone //(408)342-6867 fax

EO Products
Web links

ENGINES ONLY motorcycle and engine service.
Service available for Honda, KTM, Yamaha, Suzuki and Kawasaki off road and dual sport bikes.
Around the world ENGINES ONLY is known for our mini bike and small bore parts catalog. Locally around the San Francisco-San Jose area we are also known for our full size dirt bike motor rebuilds, maintenance and performance upgrades.
Our expert motor technicians can perform simple tune ups or complete motor rebuilds. Oil changes to race bike preparation we can keep your bike ready for your next adventure. Call to schedule an appointment to keep your bike running its best.

  KLX140 pipes now in stock

KLX160 Big Bore Kit
Wake up your KLX140 and 140L.

We have been working on the KLX140 since before they were released. Our high compression 160cc Big bore kit, cam and spring kit, Mikuni intake kit with custom throttle cable and our pipe have produced some great results.  Our big bore kit makes more power and is the most reliable kit made for the KLX140 motor. This bike is wicked fun. 
Read what Dirt Rider Magazine said about our motor. 
DYNO of our KLX160 motor kit click here

CRF150R Complete race ready heads in stock.
Big valve hiflow heads with competition seats and valves. $1199.95
This is the head your competition is not telling you about.

CRF150R stock bore HiCompression pistons in stock. $249

Our new Outlaw series low pipe for DRZ125's.
All Stainless construction for the most durable pipe your money can buy.
This pipe makes power. Great addition to our big bore and intake kits.
This is the pipe you need to win races.

HONDA CRF150R   170cc kits in stock
DYNO runs show 27.5 Horsepower and 13.5 pounds of Torque

Whats on the ENGINES ONLY CRF150R Big Bore 170cc race bike.
Applied Racing Clamps and clutch lever, Barnett clutch plates and springs, Hlebo Bros revalved forks with heavy springs and Tungsten DLC coated tubes and hard anodized axle castings and forkcaps, polished and hard anodized shock body with revalve and heavy spring, EO Megacycle billet cam with custom valve springs with titanium retainers, EO 170cc Ultimate Big Bore Kit with forged racing piston, EO Outlaw series slip-on muffler with spark arrester,
EO Tokyo Mods modified and jetted CRF150R carb, EO RoostMX graphics kit, Moto and Supermoto wheels with Talon hubs and Excel rims by A&A Racing, EO Steahly flywheel weight and a bunch of little stuff and lot's of sweat from some great industry people. 

Click for Dyno chart

Fits CRF150 & 230F and CRF150R

EO Shroud Graphics $59.95

Fits DRZ/KLX125 in Blue and Yellow

Yamaha TTR125 and 230    Honda CRF80F, 100F, 150F, 150R soon, 230   Suzuki DRZ125L Kawasaki KLX125

Big Bore Kits, 250cc, 
Outlaw exhaust systems, AMA legal
32mm Mikuni intake kits complete

Big Bore Kits, 190cc, 
Outlaw exhaust systems, AMA legal
Non linkage REAL shift lever

2006-14  CRF150F 225cc Big Bore motor kit. Bolt on. Runs on pump gas.
Now get 225cc and monster torque with electric start. $599.95      More info

2003-2005 Ultimate CRF 150F Big Bore motor kit. ENGINES ONLY 250cc Ultimate kit. GO  BIG

Check out the review of our CRF230f- 250cc Big Bore Kit  from the people at: 

   Fits 2008+ CRF230L and CRF230M
Competition use only.
CRF/XR 80 120cc Big Bore kit

Go Big with this sleeper kit CRF/XR80 120cc Big bore kit 11 horsepower from your 80          Click here for more info

Suzuki/Kawasaki DRZ/KLX 125
190cc Big Bore kit

All EO motor kits run on 91 octane pump gas.
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Complete DRZ/KLX 125 Big Bore kit
The proof is in the power.

187.80cc, 10.5:1 compression ratio, produces 16 horsepower with our carb and Outlaw pipe.
Includes cylinder resleeve / piston, rings, clips / gaskets / performance camshaft / performance valve springs.
With cylinder and camshaft exchange $799.95  Outright no exchange $999.95

f EO DRZ190 trainer for 5 time GNCC champion /AMA National Hare Scrambles champion / Factory Suzuki rider Rodney Smith.
Great article about Rodney. click here

EO_OUTLAW  Series high pipes
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Outlaw pipes are built and finished in the United States.

Our true megaphone style pipe produces the best horsepower and torque in all RPM ranges.
More bottom end and more top end.


All our high pipes include a tuned head pipe and spark arrester..


SuperTrapp 4" tunable plates (CA 96 DB legal) disperses noise radially with no loss in power


Aluminum heat guard for enhanced rider protection


Our pipes are stainless steel.


Available for Honda XR / CRF80,100,150,230, Yamaha TTR125, Kawasaki / Suzuki DRZ/KLX125.    Now $499.95   +++Competition use only.+++

OUTLAW series low pipe now available for CRF80F, 100F, 150F and 230F, does not fit "L".
Dirt track, supermoto and road racing applications. This pipe makes lots of power.
Includes: Stainless steel pipe and all mounting hardware. $349.95ea 
+++Competition use only.+++

***ENGINES ONLY CRF230 big bore makes 23.25hp ***
***ENGINES ONLY CRF150 big bore makes 18.81hp ***

CRF230/250cc dyno charts. CRF150/175cc dyno charts.

Engine Performance Kits
All EO performance kits run on standard 91 octane pump gas.

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CRF 100, 150 and 230 BIG BORE KITS 
  CRF230F  and 230L to a full 250cc.

ENGINES ONLY kits ready now.

 CRF100 Big Bore Kit. Only $499.95**
120cc kit raises compression and increases performance.

**EO CRF150 28mm Performance Carb. kit**

Works great with our CRF150F / 225cc Big Bore kit.
This kit works with stock airbox or K&N filter.  
Now $349.95

CRF 150 carb kit stock boot.jpg (346857 bytes) CRF 150 carb kit.JPG (897764 bytes)

CRF and XR 80, 100, 150, 230, 250 and 400 PoweRing.
Includes all hardware for easy bolt on installation.
This exhaust end fits on your stock XR or CRF pipe in place of the stock baffle. Increases power by being less restrictive than the stock baffle. No drilling or cutting required, it bolts right on. 
Remove your baffle and mount a less restrictive EO PoweRing.
Our 12 plate exhaust is adjustable to meet AMA and CA 96db noise requirement.
Plate type spark arresters disperse noise radially for quieter operation and avoid the clogging of screen type spark arrestors.
Increased performance and an inexpensive alternative to high priced "Exhaust Systems".  Now only $124.95
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Our Mission

To provide the highest quality, most reliable products in a timely and efficient manner so that you are smiling every time you ride your bike.


Company Profile

ENGINES ONLY was started in 1990 By Frank Nye who was prodded by fellow dirt track riders to make quality big bore kit for the then standard training bike the Honda XR100.
Our first three motor kits went to Bubba Shobert, Wayne Rainey and Kenny Roberts. While we still sell most of our parts and motor services to the professional racing community, our products are designed for use on regular pump gas and are meant to be reliable, long lasting and stand up to the abuse of training, trail riding or racing. Our motor components make great torque and have a wide usable powerband. All of our products are parts that we have personally ridden and tested for many hours so you can trust them to perform for you.

ENGINES ONLY continues to develop, test and provide quality products to the minibike community for Honda, Yamaha, Suzuki and Kawasaki motorcycles. We intend to bring new and innovative products to production as the industry evolves and expands with future four stroke minibikes.


Contact Information

(408) 275-6300
(408) 342-6867
Postal address
1870 Stone Ave. San Jose, CA 95125
Electronic mail
General Information: enginesonly@yahoo.com
Sales: enginesonly@yahoo.com
Customer Support: enginesonly@yahoo.com
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