DRI has spent 1000's of hours doing R&D on 2-stroke Engines/Cylinders/Port types designs to MAXIMIZE PERFORMANCE and RELIABILITY . There are no quick read manuals to explain the complexity of 2-Stroke porting.
Data must be gathered-recorded and analyzed, to help properly design cylinders that not only perform properly but give the reliability and consistency expected from DR/PTR Cylinder.

• DRI has proven port designs for ALL Applications; Desert, MX, XC,  Off-Road, Sand Dunes and Sand Drags, Ice Racing, Enduros, Serious Trail Riding, etc.  You name it DR has built cylinders that have raced it.

• DRIs have won more Pro ATV Races and Pro ATV Championships than any other company in the world over the last 4 decades. DRI has spent 100's of hours  doing R&D on 2-stroke port cylinder port designs

• All port work is 100% Guaranteed

• All PTR cylinders have port timing degreed in and all port dimensions are blued and scribed for MAXIMUM consistency

• PTR Porting is a labor service modification

• All PTR porting is performed in house. By Loren Duncan

• All PTR ported cylinders and individually serial numbered. With data recorded in a DRI data file, for future reference

• For Maximum performance and reliability with a PTR ported cylinder it is imperative the piston, rings and cylinder bore are kept good conditions.
  Piston clearance should ALWAYS be kept under .005 of an inch * Contact DRI for more details

• Quality Cylinder Boring and Proper Port Chamfering is critical to the performance and reliability of your cylinder.
  When these services are required for your engine, be sure that they are performed by DRI or a highly trained technician

• Call DRI for one on one consultation about, your machine, your riding and your needs. #619.258.6306
  
  
  
  Suzuki LT 250R Porting Type Options
  
  NATIONAL Cross Country (low end)
  
  NATIONAL Midrange (midrange)
  
  ELIMINATOR (midrange/top end combo)
  
  HIGH REV (top end)
  
  All PTR porting types same price.
  PTR Porting and Stock Head Rechambering $595.00
  
  PTR Porting (use Powerhead at additional cost) $595.00
  Powerhead without headstay $299.00
  *If customer already has a Powerhead, they may purchase a matched dome(for ported cylinder)for $49.95 and use their existing Powerhead outer shell.
  
  *Cylinder Boring and Piston are not included in price. DRI can bore cylinders and supply new piston at additional cost
  DRI does not offer a big bore kit for Suzuki LT 250 due to reliability concerns
  Models
  Fits:
  Suzuki LT 250R 87-92
  
  Cores Required
  Cylinders and Head(if stock head modification is desired)
  *Customer must send in their cylinder for PTR Port modification or purchase new cylinders direct from DRI
  
  Power Emphasis
  NATIONAL XC: Power emphasis very Strong Bottom and Good Midrange Pull
  Best Carburetor:36mm PJ Keihin
  Best PTR Pipe: Type 6 or Midrange
  
  NATIONALMidrange:Good low end throttle response, excellant midrange, good top end,
  likes to pull a taller gear
  Best Carburetor:36mm PJ Keihin or 39mm PWK Keihin
  Best PTR Pipe: Midrange
  
  ELIMINATOR:Power emphasis; good Bottom end Strong Midrange Pull, Very Good Top End.
  Strongest Power at 3/4 throttle
  Best Carburetor:36mm PJ Keihin or 39mm PWK Keihin
  Best PTR Pipe: Midrange RACE, Eliminator, High Rev
  
  HIGH REV Kit:Fair low end throttle response, Good midrange, excellant top end,
  Revs out Very Well
  Best Carburetor:39mm PWK Keihin
  Best PTR Pipe: High Rev or Eliminator
  
  Power Gain
  20% over stock, peak
  
  Reliability Rating
  With proper maintenance, PTR Porting is 85% reliable as stock
  
  Application Recommendation
  XC/Low End: Cross Country/Tight Woods Riding and or Racing
  
  Midrange: Motocross, Sand Dune Riding, Trail Riding, Gran Prix Races,
  *Best Overall PowerBand
  
  ELIMINATOR: Excellant Dual Sport type riding, Motocross, Trails, Sand Dunes,
  Very Versatile
  
  HIGH REV: Drag Racing, Hill Racing, large TT's and Flat Tracks
  
  
  
  Special Notes
  Paul Turner Racing Products are a proprietary brand of Duncan Racing International, Inc.