pludmugger Posted March 29, 2012 Report Share Posted March 29, 2012 (edited) Hi all. I have been to look at a 1979 fantic twinshock 125cc. I have been told it has a Suzuki piston taking it to 175cc. Not sure if it was bored to accomadate. Is it a successful conversion atvb Edited March 29, 2012 by pludmugger Quote Link to comment Share on other sites More sharing options...
blocky Posted March 29, 2012 Report Share Posted March 29, 2012 There are only 2 ways the capacity can be increased. Change or modify the crankshaft to increase the stroke, This is highly unlikely. Change the diameter of the cylinder by boring to a new size. This is probably what has been done. A common modification to the 125 was to fit a barel and piston from the 200 engine to give 156cc which was relatively easy. I could see that whilst it would be possible to open this up to 175cc I would think that at that size the cylinder would be quite thin especially near the holes where the studs pass through, The cylinder head would also need modification. Bearing this in mind, I would think the proof would be in the pudding and I would expect to see a worthwhile increase in performance over a 125 model which I always felt needed to be given some "stick" to get it going and made it hard to find grip in the mud. I'd love to have a try on this beast for myself sometime. Hope this helps Quote Link to comment Share on other sites More sharing options...
bigwig Posted March 29, 2012 Report Share Posted March 29, 2012 We used to sell Fantics at the time and the 175 with Suzuki piston was a complete failure. Port timings were a long way out. Standard 125 was much better then the 156 better again. Quote Link to comment Share on other sites More sharing options...
jimbo349 Posted March 29, 2012 Report Share Posted March 29, 2012 We used to sell Fantics at the time and the 175 with Suzuki piston was a complete failure. Port timings were a long way out. Standard 125 was much better then the 156 better again. I had on in the mid 80's they are fitted with a TS 185 piston from memory, it was as flat as a pancake fine on the flat but no good for climbs. Avoid it and buy a std 125 bike or a 200. Quote Link to comment Share on other sites More sharing options...
bilc0 Posted March 29, 2012 Report Share Posted March 29, 2012 (edited) I've had the suzuki 175cc piston conversion in my Fantic 156cc for some years now. They press in a purpose made iron liner, i'd say the liner is thicker enough to get another 2 rebores out of it and yes you will need to have some head work done which is'nt a problem either. As long as the conversion is done by someone who knows what there doing the motor works well with it. Come to think of it mine has the 185cc Piston. Edited March 29, 2012 by bilc0 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.