stevecarter1000 Posted May 23, 2010 Share Posted May 23, 2010 I have a fantic 156cc engine (with a 125cc bottom end) in an 80cc frame.... It needs a new piston ring - I've heard the term 'Dykes' Piston Ring and wondered what this is? Also, is there an obvious way to tell whether the piston is std or oversize? I've also heard of a suzuki piston being fitted - what is the difference and benefit compared to a Fantic piston please? All help gratefully received - cheers. Steve Quote Link to comment Share on other sites More sharing options...
stevecarter1000 Posted May 23, 2010 Author Share Posted May 23, 2010 Also, the con-rod has a slight amount of play side to side on the big end bearing. There is no discernible twisting play, just side to side. Is this ok? Ta Quote Link to comment Share on other sites More sharing options...
stork955 Posted May 23, 2010 Share Posted May 23, 2010 Gday, I cant help with the ring, but a rule of thumb is that if the rod side clearance is getting over 20 thou, its time to rebuild the crank. You may be able to find an accurate specification somewhere on the net. To measure it just slip larger and larger feeler gauges in between the rod and the crank until you can no longer get one in. The largest one that fits is the side clearance. Cheers, Stork. Quote Link to comment Share on other sites More sharing options...
copemech Posted May 24, 2010 Share Posted May 24, 2010 I have a fantic 156cc engine (with a 125cc bottom end) in an 80cc frame....It needs a new piston ring - I've heard the term 'Dykes' Piston Ring and wondered what this is? Also, is there an obvious way to tell whether the piston is std or oversize? I've also heard of a suzuki piston being fitted - what is the difference and benefit compared to a Fantic piston please? All help gratefully received - cheers. Steve Dykes rings are "L" shaped rather than a "--" shape in the slot, quickly spotted, usually on top groove! Just need to look at things and measure the piston accurately with a micrometer to see the exact size to compare specs and hopefully figure out what you have. Quote Link to comment Share on other sites More sharing options...
stevecarter1000 Posted May 24, 2010 Author Share Posted May 24, 2010 Guys, many thanks! I'll measure the play as you suggest Stork... Ref the Dykes ring, is it a choosable alternative fitting for that engine, or does it HAVE to be the Dykes ring? If it's either/or, what difference does it make? Thanks again, Steve Quote Link to comment Share on other sites More sharing options...
stork955 Posted May 24, 2010 Share Posted May 24, 2010 Gday, the Dykes ring is a special fitment - if it had one before it can only use that ring because of the shape. They are the same type as in TY yamaha's. They do work well. Cheers, Stork Quote Link to comment Share on other sites More sharing options...
jimbo349 Posted May 25, 2010 Share Posted May 25, 2010 The Fantic 125cc engine was modified by a guy in Wales years ago and fitted with a TS185 piston and I think a cast liner in the barrel. Fantics generally had chrome bores at the time. I had one of these bikes and the engine was very flat and had none of the zip the Fantic 200 had. Thats all I can say about the bike I had great for anything that didnt involve a big climb. Quote Link to comment Share on other sites More sharing options...
pat Posted February 20, 2011 Share Posted February 20, 2011 (edited) Borrowing this thread.. Will kindly ask if any of you know, if any one back in the days did rebore/replate 156cc up to 63.0, 63.5 or 64.0? BR, Edited February 20, 2011 by Pat Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.