KTM 2 Stroke Engine Services

FAQs

Q. Why have you discontinued the Mule Porting service?

A. 40 years was enough. It’s a very nasty, dirty job that is unhealthy and I’ve had enough. I’m done.

 

Engine services for KTM 125, 200, 250, 300, 380 EXC, MXC, XC, XC-W, SX ’98-’12

Engine

>>Download a Service Order form – click here<<

Slavens Mule Port & Polish  Notice: This service is discontinued.

$499 – KTM 200 EXC/XC/XC-W ’04 – ’12

This mod gives a major increase to the bottom-end and mid-range torque with added top-end over-rev, all of which make it easier to climb hills/mountains and allows you to use taller gearing. 1st gear will be more usable and 6th gear will be better for cruising to the next trail head. The power delivery is smoother than stock and enables you to put the power to the ground on slick surfaces and makes it less tiring to ride all day long. Fuel mileage is improved and pump gas works well. Like all of our Mule Porting, this is not a minor change. It’s a major boost to the entire power-band that makes it much easier and more fun to ride and more competitive against larger displacement engines.

  • Major increase to low-end and mid-range torque and horsepower with increased top-end over-rev
  • Smooth power delivery
  • Increased torque makes it easier to ride
  • Pulls a taller gear in most situations (climb hills in 3rd that you used to climb in 2nd)
  • Increases traction
  • Makes it easier to re-jet
  • Increases fuel mileage
  • Does NOT decrease engine life
  • Runs on pump fuel
  • 3 – 4 day turnaround time with an appointment
  • Does NOT include servicing, cleaning, or re-assembly of powervalves

 

Slavens Mule Port & Polish  Notice: This service is discontinued.

$499 – KTM 250EXC/MXC/XC/SX/XC-W ’04 – ’12

Most years of the KTM 250 have mid-range power-band engines with weak bottom-end power, a decent mid-range, and a lack luster top end with a likeable quick reving, light, and zippy feel. The Slavens Mule Port & Polish gives a major boost from bottom to top yet retains the likeable stock traits. The much needed boost to the low-end and mid-range torque will make it pull much harder off corners and up hills, will require less clutch action and added top-end hit and over-rev will come in handy on long straights when you want to blast by a friend or competitor. This mod must be combined with a SX head.

  • Major increase to low-end and mid-range torque and horsepower with good top-end power
  • Smooth power delivery
  • Increased torque makes it easier to ride
  • Pulls a taller gear in most situations (climb hills in 3rd that you used to climb in 2nd)
  • Increases traction
  • Makes it easier to re-jet
  • Increases fuel mileage
  • Does NOT decrease engine life
  • Runs on pump fuel
  • 3 – 4 day turnaround time with an appointment
  • Does NOT include servicing, cleaning, or re-assembly of powervalves

 

Slavens Mule Port/Polish/Decking/Head Mod  Notice: This service is discontinued.

$629 – KTM 300EXC/MXC/XC/XC-W ’04 -’10

$589 – KTM 300XC/XC-W ’11-’12

The Mule Port & Polish/Cylinder Decking/Head Mod combination offers a significant boost to the low-end and mid-range torque and horsepower. It’s NOT a minor change that you can barely notice, it’s a major boost. The increased torque and horsepower produces smooth power delivery which makes it much easier to ride, increases traction, and enables using a taller gear in most situations. These mods, when combined with a Slavens Mountain Jet Kit, increase fuel mileage.

All cylinder decking and head mods will have the compression ratio adjusted to work in the elevation range in which they will be ridden. (example: engines to be used at low elevation will have a lower compression ratio than engines designed for mountain use only)

  • Major increase to low-end and mid-range torque and horsepower with good top-end power
  • Smooth power delivery
  • Increased torque makes it easier to ride
  • Pulls a taller gear in most situations (climb hills in 3rd that you used to climb in 2nd)
  • Increases traction
  • Makes it easier to re-jet
  • Increases fuel mileage
  • Does NOT decrease engine life
  • Runs on pump fuel
  • 3 – 4 day turnaround time with an appointment
  • Does NOT include servicing, cleaning, or re-assembly of powervalves

Head mod

I have been riding 300′s since they first came out in 1990 (currently own a 2010 300xc-w) and have devoted 100s of hours to refining this power-plant.

Other than correct jetting, this is the first performance mod that should be performed on 300′s, before pipes or carburetor devices. It gives more bang for the buck than any other mod or bolt-on item and makes the bike much easier to ride.

My 300 gets 90+ miles per o.e.m. tank.

Jeff Slavens
Engine builder for Team KTM, Team Suzuki, Team Yamaha, Team Husqvarna, longtime consultant for
Randy Hawkins Team, Am Pro Yamaha

 

Head Mod  -  Available

$55 – KTM 300EXC/MXC/XC/XC-W ’04 -’14

Very noticeable and usable boost to the low-end and mid-range power that will make your 300 easier to ride. This mod can be used with a stock or ported cylinder. This is a very inexpensive bang for the buck…. a no brainer.

  • Works well with pump gas, race gas is not needed or recommended
  • Does not require re-jetting
  • Helps clean up jetting issues
  • Does not adversely affect top-end performance
  • Machining/compression ratio is adjusted to match your elevation
  • Compatible with all types of riding & racing
  • Does not increase coolant or engine temperature
  • Does not include new head o-rings or jetting specs
  • 2 day turnaround time – no appointment, email, or phone call necessary
  • Please include a completed service form with the shipment

KTM 250 head mod - We do not offer a 250 EXC, XC, XC-W head mod because the 250 SX head (available here>>>250 SX head) is far superior to machining the stock head.

Cylinder Decking (machining the base gasket surface)  -  Available

$65 – KTM 300EXC/MXC/XC/XC-W ’04 – ’11

This mod, when combined with the head mod, is the biggest bang for the buck on ’04-’11 models. It gives a big boost to the low-end and mid-range torque. If you are watching your budget, I highly recommend the cylinder decking combined with the head mod.

Pump gas works well, race gas is NOT needed.

Turnaround time is 2 days. No need for an appointment, email, or phone call. Just include a completed service form and ship it.

Powervalve Service  Notice: This service is discontinued.

KTM 200/250/300 (All years) $89

  • Dis-assemble
  • De-carbon, clean, polish
  • Assemble & lubricate
  • Set timing
  • Set “Z” dimension (flap height) (250&300)
  • Install new o-rings
  • Seal front cover plate
  • Parts are NOT included