R5B piston styles

[Greaser Greg]

Great to have this info, everyone. Does the segmented ring go  under the top or bottom ring? None of the manuals I have specify where it goes. i ordered some, but they are not here yet, so I can't read the instructions and figured I'll just ask here in case the instructions got lost.

[SoCal250]

I think you're referring to the ring expander, which goes under the bottom ring. Some engine builders say this should be left out because they can break, others say go ahead and use them since Yamaha designed the ring to be used with the expander.

[bracket maker]

dykes rings work fine stock. piston port is antique. might be a good time to add reeds and change the pistons and porting to a modern configuration. I've seen some rd jugs on the net.

been there before with piston port dykes rings.


the ring expander goes on the lower ring like socal says, you can leave it out. I left mine out and had no issues. I don't like the idea of little bits of metal breaking loose if I soft sieze. left it out because I read to do that here. 

[m in sc]

i dunno, i really like my R5 and T500 piston port motors. Nothing wrong with them and i can do 85+ with a passenger on the r5.  I mean, i get it, if its going to be a hot rod, different story. 

as an fyi, i did contact cruznimage in japan, they currently have no plans on R5 pistons, but im sure they could be swayed if theres enough interest.   

[bracket maker]

i dunno, i really like my R5 and T500 piston port motors. Nothing wrong with them and i can do 85+ with a passenger on the r5.  I mean, i get it, if its going to be a hot rod, different story. 

as an fyi, i did contact cruznimage in japan, they currently have no plans on R5 pistons, but im sure they could be swayed if theres enough interest.

I know you get it. you didn't say if you run the expander on the bottom ring.

[m in sc]

On those I do. On higher revving motors, typically not.