Part # PH-1000 Honda TRX 250R Powerhead without stay $249.00
Part # PH-100H Honda TRX 250R Powerhead with stay $259.00
kit includes: head shell and dome,

Also fits 85-86 ATC 250R

Replacement Parts
Part # PH-100D- Dome each (15cc-22cc) $49.95

Information Required when ordering:
Type of Fuel
Piston Size
Are cylinders ported or stock? If ported need exhaust port
height(in mm's or degree's)
Cylinder Length (has cylinder been decked or based)
Altitude

Special domes are offered for Lasco 300cc kits installed in stock cylinders.

CNC machined from billet aluminum

20% more cooling area for increased reliability

Interchangeable domes available in various sizes

Uses stock OEM Head gaskets

Correct spark plug angle

Billet water fitting bolts on

Uses stock OEM head nuts

Works with stock or modified engines.

Domes are specially machined to DRI/PTR specifications; for correct squish angle, squish clearance, dome diameter.

What are advantages of adjustable domes

For stock cylinders that want a slight boost in compression

For high altitude riding

For ported engines

For alcohol engines

To adjust powerband. Raise for add low RPM torque, less let's engine Rev.


Carburation jetting should be check after Powerhead installation


Notes on Compression:
Engine compression is lost as elevation is increased.
Engine compression is lost as exhaust port height is raised(as in porting)
Engine compression is increased as piston size is increased


PTR Powerheads are a proprietary product of Duncan Racing International, Inc.