View Full Version : XR400 HRC compression

30-08-2005, 11:01 PM
Does nayone know what the compression ration for an XR400 is fitted with the HRC high compression piston is ??? Is it worth putting one in???

01-09-2005, 06:45 PM
The HRC Power Up booklet says 11.0:1
I run a JE piston in mine. I think it is high 10 compression ratio.
Certainly worth doing. Extra low down acceleration out of corners.

06-09-2005, 12:31 AM
I have a 98 XR400 with the HRC kit that is piston, cam & clutch basket. Really big difference to the standard 400, but with the 11: 1 piston you have to run prieum fuel or it does not run to well. But much nicer to ride easy on the mono & plenty of punch