Anyone have a part number? bore size? I emailed them Thanks for the inquiry. I'd be glad to see if I can help. I am assuming this is a piston that you are currently using. What bore size are you running, or are there any numbers stamped on the dome of the piston?
I've never heard of a 300cc wiseco piston. I hope you find out some info..
Piston sizes for Tecate big bores are water craft pistons that need machine work! Example: A 76 mill piston is a 294 cc!
This is where i got my info from http://www.3wheelerworld.com/group.p...iscussionid=11 Read the second post
I did an exhausting search on this topic a few years back and talked to a few builders that made these kits. From what I remember Wiseco did a production run of 300cc size pistons for the Tecate/KX250 which were the same dimensions as Tecate only larger diameter, however these pistons are long gone and discontinued. There were also a few builders who used pistons from Ski-Doo (Rotax motor) Formual 1 583 snowmobile that start in 76mm and go to 78mm. This is the desired piston over the Jetski for 2 reason as it has the same distance from the wrist-pin to the top of the piston and you do not have to cut the piston skirt to make it work. It is a single ring design, and still available.
I used a 77.50 Wiseco Piston water craft piston.....no matter what piston you get for your big bore, it is not race ready if not machined properly ie: intake windows need to be drilled, skirts on my particular piston needed to be cut for clearance, and the port timing edge of the piston needs to be machined and beveled with a Bridge Port!
On the Rotax piston you don't have to do any mods to make it work, you could add the boost ports for performance but it will work without them. Also I would only add boost port mod on forged piston like wiseco. The best way would be for everyone here to jump in on a order to have Wiseco just make the Tecate pistons in the larger size like they used to.
I agree 3Razors....however I have seen that single ring piston you are talking about! The piston I saw was the same as other water craft pistons I have seen and used! The crown of the piston is flat with no beveled edge, causing the piston height to be in the transfer port when the piston is completely at the bottom of the stroke.....it will work, but I believe the performance suffers. My buddy installed it that way and it ran so so.....pulled it out and machined it correctly and it runs way better. We just machined the piston to Wiseco Tecate specs! I also bridge ported the wrist pin area to lighten the piston up....as Wiseco skips that stage in machining process! I can tell you this.....piston prices are threw the roof anymore!
Good points Tecate50, your findings are good enough for me. I've only have hearsay results and after your findings I would have done the same. Those mods are the difference between a good running bike and an excellent one!
You need to do a search for a Kawasaki JS300/650 jetski piston. 549M is the start of the part number.
