going powervalved on tri-z,have ?'s

[1bad86tri-z]

I just purchased a complete(minus carb)'86 YZ250 engine. I'm going to swap the powervalve setup onto my tri-z bottom end. I'm in the process of gathering up all the other parts that I will need. I am planning to port the YZ cylinder. I was also going to bore it if necessary and install a wiseco pro-lite piston. I also plan to use the tri-z head so the coolant port comes out to the side. Do I have to modify it at all to use it on the YZ cylinder? Should I shave the head at all? Also,I was wondering what size carb I should run? Would a 38mm keihin be sufficient? Any other pointers would be appreciated. Thanks.
Garry

[bman200x]

Check this article out. It tells you what needs to be done for the powervalve assembly. :thumbsup:

http://www.3wheeler.org/3wheeling/12-84%7Epg38.html

[my90rulz]

You need to use a YZ head with the YZ cylinder, the tri-z head will fit on but it wont cover all the gasket surface and the YZ use's o-rings so it wont work.

[1bad86tri-z]

Thanks for the info guys. I guess that I'll have to use the YZ head after all. I compared the two and they are way diferent! Oh well! My cylinder and head are at the machine shop right now. I'm getting the cylinder bored,honed and ported. I'm also getting the head shaved a little. Gonna keep it running on 92 octane though. I'm going with a wiseco pro-lite piston and I decided to go with a PWK 40mm keihin flatslide carb too. This thing should really scoot when it's done! I can't wait!:headbang:

[CHAINSAW]

If there is nothing wrong with the YZ bottom end, Id drop it in there. I dont think Derrick ever got his running decent, but those of us that have the complete YZ motors dont have any problems at all.

[1bad86tri-z]

chainsaw,
I thought about just swapping the whole YZ motor into my tri-z. The problem is that the YZ motor has a cracked case near the sprocket. It looks like it was the result of a thrown/broken chain. It was repaired,but not real well. Also,I bought the YZ motor non running and don't know if the bottom end is ok. I know there is nothing wrong with my tri-z bottom end,so I'll probably end up using it with the powervalve stuff on it. The swap looks pretty straight forward,but I'll let you guys know how it turns out. Hopefully my results are positive,not disappointing.
Garry

[diggerzmound]

Two more big hurdles to jump are intake and exhaust. I have completed my PV swap and ran into a couple of the major issues while I was there.

The intake on a YZ points off to the left where the Tri-Z is centered. the easiest solution is to use a clamp on filter and not use the entire airbox setup. I wanted to use the airbox, so I had someone machine me a wedge. http://www.imagestation.com/picture/sraid163/pab236601509e25386c447f38194d3801/f4908e79.jpg

The next problem will be the exhaust, on my 85' YZ cylinder the exhaust outlet Outside Diameter is too small to fit the inside diameter of my DG Tri-Z pipe. So again I had a tolerance fit space made to seal the pipe to the exhaust coming out the cylinder.
http://www.imagestation.com/picture/sraid163/p89851d03b9667bfb727b639bde055a7c/f48f0f95.jpg

Its a screamin demon now, I think it will hang with a good number of banshees now..

[250sx]

Looks great! How much did those extra parts cost?

[diggerzmound]

My brother works for a company with all the tools necessary.. And he likes Beer!! :cool:

[250sx]

how much beer to make another pair? :D

[03 ORANGE SHEE]

im 45 miles from ya if ya want to check out mine, then alll the ?? will be answered from a visual picture

[1bad86tri-z]

Thanks for the reply 03 orange shee. I just might take you up on that sometime. I'd like to check out a powervalved Z in person before I dive into this ordeal. I'd like to see how some of the intake and exhaust issues are handled. My cylinder and a few other parts are STILL at the machine shop. But hopefully I'll get them back soon so I can get started on this powervalved project. Talk to ya soon.
Garry

[wvtri-z]

Hey one bad 86, did you justout bid me on that 86 YZ250 on ebay?? lol I'm doing the same project to my 86Z. Hey guy's thanks for more info on the swap.