TRI-Z Big Bore Kit.. I think?

[samuraiguys]

I was diggin thru my box of TRI-Z parts I recently acquired. Came across this Jug and Piston. Looks like shes punched way out and it has a brand new Wiseco Piston that is 76.5mm. Jug is cracked on the lower portion. May be able to weld it up but not certain. Does anyone have any information on this setup?

[samuraiguys]

Part number is coming up as a Kawasaki piston? It fits perfectly into the bore and wirst pin fits the rod.. Someone had something up their sleeve lol

[Mosh]

It's definately been big bored and sleeved. You can tell by the way the sleeve cuts into the intake ports and casting was removed to fit the sleeve. IMO, no offense, but it looks like a failed attempt in my opinion, unless someone backyarder tried doing some alterations and made it look all barbaric like that. It just does not look to be a even semi professional job. It would be interesting to see the head, as it would have had to of been modified to fit the jug, and would have required some type of special head gasket to get it sealed. Regardless what you have there is non useable and the jug is destroyed beyond repair. Z jugs are very porious and most likely that could not be welded reliably.

[tecat-z]

I agree with Mosh likely beyond repair. The intake bell was welded prior to boring and sleeving. This was done
to allow room for widening of the intake sub ports. Tri-z cylinders were cast so cheaply that the area around the
Holddowns was much thinner on the side where there was no sub port. Often times this was the reason for the
corner cracking after people would open it up. There was no extra meat cast into this design, and when heavily
Modified with high compression and big bores, they often fail. Proper fuel and jetting is critical with those types
setups. Detonation puts lots of stress on the holddowns.

[RIDE-RED 250r]

^^^^Good advice there, on both counts.

[samuraiguys]

So then someone KNEW what they were trying to do, just didnt accomplish it very well. Anyone interested in the parts for anything?

[nstyle73]

The Sprock kits run that piston, both Tri Z and Tecate, but are well done and I believe the pistons are cut on top to accommodate the compression increase. At any rate, the gentlemen above know much more about the Tri Z cylinders than I.