Home Forums Shifter Karts CR80/85 Tech Talk Reply To: CR80/85 Tech Talk

Gary Smith

Shaun, I have 4 motors, 2 are stock, 1 is a 105cc big bore and the other is a modded cr80. I currently have 3.5 hours on the modded motor, and still running strong. The Honda  service manual says the piston and ring should be replaced at 7.5 hours with the piston pin and bearing being replaced at 22.5 hours. I figure the piston and ring can go a little a little longer than the recommended  time rather than the small end bearing. I have been running these CR80’s for 6 years and doing top ends every 11-12 hours with no problems with piston or rings. The ring gap after 12 hours is at the max of the service limit, which I feel is taking the parts to the limit. The only failure I had was at 11.5 hours,the small end bearing cage broke into 3pcs, but remained intact, no damage to anything. The motor was running fine, I only found out about the bearing doing my routine top end rebuild.


#55 Honda CR80.