For the past few months the little hotrod was burning more oil than normal, like when idling you could see it. Pulled the plugs and the rear one was getting oily, compression was still over 200 on both jugs so I pulled the heads to replace the valve seals to see if that would helps but found this instead.



At first I thought I threw a C clip ?



But closer inspection showed the C clip was still there in the groove, that's not good !!




I've now heard this has happen before and have a new jug and piston on the way, but decided I'm not going to use the round wire C clips anymore.
Apparently the piston gets too hot and the C clip groove expands thus allowing the C clip to expand too allowing the wrist pin to slide past the C clip resulting in contact with the cylinder wall. RIGHT......... me think's they cut the groove alittle too deep and the round wire C clip expands when Forged pistons expand, cause forged pistons expand more than oems one's.

My fix, taking a few thousands off the ends of the wrist pins allowed me to install some stronger internal retainers. They have rounded ends to prevent the wrist pin from moving and fix snug in the groove too.

Heck my Suzuki dragbike uses teflon buttons and never had a problem with them for 10 years now, but Harley pistons are not disigned for them.

I also use the same type of retainer on my Ford 302 with Vic Jr heads and 275 shot of nitrous and never had a problem turning over 7 grand with them for 15 years now so the Sportster should love them.





I'm not going to change the way I ride my bike, heck she still did 120 mph last week as is

 

Thanks for taking the time to show us that trick. Too bad it cost you thought.

 

Yeah, I'm not a big fan of those C clips.

I know I'm not the first to run into this problem or the last either !!!

You have been warned HotRodders