Are there two different, or more styles of stock r5 Pistons? I don't know how to reduce file size to post pics. The Pistons I received from eBay are different in that the crown of the piston is recessed to expose more of the first ring land, and the lands are both farther up. The ring will be exposed to combustion with just enough piston to hold it in the groove. Is this the right piston? Same in other aspects.
That would be a piston that has a Dykes top ring. They are an L shaped ring that comes up the side of teh piston to provide better port coverage/sealing/timing. They fell out of favor for reason of cost of manufacture and higher revs require lighter rings, so they are less common today.
Well crap I bought some. :bang:
If you need to find rings for your pistons, I have this info in my notes
RD350 piston rings - Dykes style ring set
360-11610-02-00 STD
360-11610-12-00 1st over
360-11610-22-00 2nd over
360-11610-32-00 3rd over
360-11610-42-00 4th over
:vroom:Thank you, that's very helpful.
Quote from: Greaser Greg on February 28, 2019, 08:30:21 PM
:vroom:Thank you, that's very helpful.
Since you brought this up I'll update my personal notes and add the info the the Tech Library for future reference. I'm sure others will have the same question. In fact, while looking at rings for you on Ebay I noticed a lot of sellers offering mismatched pistons and ring sets in their auctions. You could even see in the photo that the piston was Dykes and the rings were keystone.
Quote from: teazer on February 28, 2019, 06:29:30 PM
That would be a piston that has a Dykes top ring. They are an L shaped ring that comes up the side of teh piston to provide better port coverage/sealing/timing. They fell out of favor for reason of cost of manufacture and higher revs require lighter rings, so they are less common today.
Thanks, teaser.
So, they will work fine in a stock motor as long as I don't over-rev too much, correct?
Quote from: SoCal250 on February 28, 2019, 08:55:52 PM
Quote from: Greaser Greg on February 28, 2019, 08:30:21 PM
:vroom:Thank you, that's very helpful.
Since you brought this up I'll update my personal notes and add the info the the Tech Library for future reference. I'm sure others will have the same question. In fact, while looking at rings for you on Ebay I noticed a lot of sellers offering mismatched pistons and ring sets in their auctions. You could even see in the photo that the piston was Dykes and the rings were keystone.
Thanks, again. I noticed that also. Maybe I'll send 'me a note about it for the next newbie. :umm:
If you have them, run them. Wiseco used to put L shaped Dykes rings on many of their 2 stroke pistons. nothing wrong with them.
Sweet! I'm waiting for delivery of rings to go on them, and to hear about the crank I sent in for rebuild, oh yeah, and to get the cases clean, and...and....
Thanks
I don't understand. why not run shee piston kits? why go retro. dykes and keystone have been phased out for a reason. no modern bikes run them.
Quote from: bracket maker on March 04, 2019, 10:23:25 AM
I don't understand. why not run shee piston kits? why go retro. dykes and keystone have been phased out for a reason. no modern bikes run them.
By "shee' i assume you mean Banshee, this isn't an RD, its an R5 - piston port.
So , early two strokes can run modern type pistons, wiseco pistons change regularly ,early Kawasaki pistons were Dyke ring type ,but now run keystone configurations , some thick ,some thin section.
Quote from: Jspooner on March 04, 2019, 12:34:34 PM
Quote from: bracket maker on March 04, 2019, 10:23:25 AM
I don't understand. why not run shee piston kits? why go retro. dykes and keystone have been phased out for a reason. no modern bikes run them.
By "shee' i assume you mean Banshee, this isn't an RD, its an R5 - piston port.
got it. so it might be a good idea to get the whole top end kit.
if you can find a full set of r5 stuff, yeah. the dykes rings run really well, however they will pack with carbon when running really old style or dirty burning oil. at the time, thats the reason they quit running them. Im sure cost was a factor as well, and then with higher revving motors they probably wear out faster due to weight, etc. Ive run them, with modern oils they work great and actually seal better. (larger contact area and the gasses push the top ring out to help seat).
I think wossner made new r5 pistons at one time with keystone rings. its basically the same as a banshee style piston with no intake hole. :twocents:
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.
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.
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.
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. :haw: 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.
Quote from: m in sc on March 05, 2019, 09:09:54 AM
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. :haw: 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.
On those I do. On higher revving motors, typically not. :twocents: