KX Riders

Maintenance & Technical => KX500 Original => Topic started by: rotarymonster on May 19, 2006, 07:04:00 PM

Title: piston wear limits
Post by: rotarymonster on May 19, 2006, 07:04:00 PM

hi, does anyone know what the wear limits are for the piston, ring, bore please?

Title: Re: piston wear limits
Post by: alan on May 20, 2006, 01:15:00 AM

Here you go!

Cylinder head usable range compression 105 -164 psi

Cylinder Warp  0.03mm

Piston

cylinder dia  86.020-86.035  service limit 86.1mm
piston dia    85.910 85.925 service limit 85.8 mm
piston clearance  0.105-0.125 mm
ring grove clearance 0.05-0.09 service limit 0.19mm
ring grove width 1.124-1.26 service limit 1.34 mm
ring thickness 1.17-1.19 service limit 1.10 mm
piston ring gap 0.02-0.04 service limit 0.70 mm
Piston pin dia 18.995-19.00 service limit 18.96 mm
Piston hole dia 19.00-19.006 service limit 19.07 mm
small end inside diameter 24.002-24.013 service limit 24.05 mm

Source 1988 kawie service manual

Alan :-D

Title: Re: piston wear limits
Post by: rotarymonster on May 20, 2006, 07:12:38 AM

Thanks a lot Alan, will check it all out.

Title: Re: piston wear limits
Post by: rotarymonster on May 24, 2006, 05:01:11 AM

unfortunately my 1986 has a different bore size it turns out (just under 86mm). i couldn't get compression over 50psi but it is difficult kicking it with nothing to bolt it to.

has anyone got the bore and piston wear limts for an 86 please? i won't need all the other dimensions and i guess the compression will be same. it looks like a new piston kit but i want to check the bore size for std or oversize piston requirement. cheers