Tri-Z experts...

[pickleweasel_00]

Ok, so got the tri-z running a couple hours ago, and being my first time riding one of these, it was a real thrill. Nothing at all like the trusty ytm200. So anyways, i got it and it had a leaking headgasket. Every time i tried to start it, the cooling system would build up pressure. So I took care of that with some new gaskets.

When i got it started, it ran good but was blowing alot of white smoke (burning the coolant i take it) I rode it for prolly twenty minutes, and the temperature light came on. So i thought i'd limp it half a mile back home. Nearly there and it dies on me. Pulled the radiator cap off and it was dry. So I'm thinking the head gasket is leaking, it burnt off all the coolant, overhaeted and died. Didn't mess with it much yet so not sure what to expect.

So now onto the questions, does this sound like the head gasket leaking? Is there any possibility something else is leaking? Could the head be warped causing it to not seal? It is a new gasket but i somehow managed to put it on backwards (180 degrees around) the first time, torqued it, took it apart, turned the gasket around, and put the head back on. Is it possible this is why the gasket failed?

What should i expect pulling it back apart? think the piston/cylinder will be scored from overheating? Bad enough for a re-bore/new piston? I will have to take it apart later and find out.

So anyways, if anybody has had similar problems before and/or can offer suggestions and advice, that is greatly appreciated :beer

[pickleweasel_00]

also, it was an Athena layerd gasket, should i go to the one piece style? best gasket to go with?

[Bryan Raffa]

ya that head gaskit was toast when you took it off the first time.. if your tranny oil is not white from a leakin mechanical seal then its the head gaskit.
with out takeing the top end off and lookin at it or doing a compression check its hard to say what damage you did. I would get a top end gaskit kit and pull it apart and inspect it..possibly a light hone and some new rings

[pickleweasel_00]

so new rings would be a good possibility? Yeah, seemed to have screwed up, but gotta lean somehow :wondering What should compression be? And if I were to put some new rings in, do i have to richen the oil/fuel mix for any type of break-in?

[ColeTrickle]

I've had trouble getting the heads to seal a few times with the Z. Last time I took a new Yamaha gasket and sprayed a light even coat of that copper gasket spray from the auto parts stores on both sides of the gasket and let it dry. Then put it together. It's sealed up good now. With a new gasket it should seal without the spray but I figured I'd try it after I went through a few gaskets.

[TimSr]

Head gasket leakage is a very common problem on the TriZ's. The steel gaskets make grooves in the head sealing surface, and the top of the cylinders get "unflat" as they get pulled upward by the studs. I always use a spray on speacially made for head gasket sealer called Copper Coat, made by Permatex, and I also now only use the Cometic or Wiseco single piece fiber style head gaskets. While Ive had lots of problems over the years with steel gaskets leaking, I have never had a Cometic gasket leak, and its all I use now.

[pickleweasel_00]

yeah, at the shop i worked at, we dealt with alot of high performance and drag cars. When we had an engine that used the copper head gaskets we'd spray them with the sealer. But I'm thinking if i used the single piece fiber gasket than i could avoid a few problems later on. While I love working on these things, it gets a little tiresome having to do the same thing over again :( I think the head is prolly straight, not sure if i should get it milled or not to be safe. Think i'd be good without? Oh, and where's a good source for the cometic gaskets? Dennis kirk only has vesrah gaskets (i'm sure they're probably good gaskets too)

[TimSr]

Do a search on ebay. Theres a guy with an ebay store that always has them.

Head is easily cheaked by taping some fine sandpaper on a piece of glass, put the head on it, and move it around a little bit in a circular motion. When you look at the surface after a little sanding, any irregularities will be obvious. Same can be done with cylinder top, but studs have to be removed.

[pickleweasel_00]

ok, will try that again. Did it once before it went together but with a piece of metal from the golf course (other job) that's used to check the reels on the mowers. It's supposed to be perfectly flat

[Bryan Raffa]

good compression will be around 160-170 you only have to run one tank through it with one oz extra than you normally run it. put some 400-600 grit wet sandpaper on some thing you know is flat like a piece of glass or steel on a work bench and move the head in a figure 8 motion to true it up, do that a few time and look at it you will be able to tell it theres any bad spots (high-low)
I have never had a head gaskit go bad or base gasket in over 15 years on a tri z and I have used every kind but the wiesco gaskits,, I would use a OEM from bikebandit.com there labled TOP so you cant go wrong on install,,I torque all mine at 20-22 not 18 like the manual says

[Bryan Raffa]

dam tim there a echo in here LMAO

[pickleweasel_00]

ok, found the guy on egay with the cometic gaskets and ordered a top-end kit. So i'll probably start tearing it back down tommorow and see what i find...

[pickleweasel_00]

ok, pulled the head off today, and it was an obvious head gasket failure (my own fault). But the cylinder, from what i could see, isn't scratched or anything. I have yet to pull the cylinder off and check the piston/rings as well. Not sure if maybe I should take the head and cylinder to the machine shop and have them checked to be on the safe side? And possibly a new set of rings just for fun? It is supposed to be a very low hour engine since re-build if that makes any difference. Maybe have them checked just for peace of mind. Any suggestions? What brand of rings do you guys like, and what's a good source to get them?

[Bryan Raffa]

depends what piston you got yamaha piston you need OEM and wiseco needs wiseco..and so on

[tecat-z]

If you want an oem head gasket that is one piece you have to use one from a 83 yz250k. It is the only year that interchanges with 85-86 z's. Oem quality and very reasonable compared to the expensive multilayer metal oem tri-z gasket. They work like a champ.

[pickleweasel_00]

B00E3
Well, i took the head and cylinder to my machine shop to get checked out to be on the safe side. Said he'd take a little off the head to clean it up, and hone the cylinder to clean it up. Now for the piston. It has "B00E3" stamped on the top of it, what does this tell you? Is it a stocker or aftermarket? The piston skirt looks scuffed up pretty bad but it still feels smooth, no ridges or anything. Debating getting a replacement. Need to get a camera and post some pics. If anything, I'll get a new wiseco piston but wanted to know if it's stock or not in case I need rings. So different brand rings aren't compatible with different brand pistons?

[Bryan Raffa]

to truly know what size it is your gonna have to have it mic. at a shop.If you go with a wiesco and you have a oem piston your gonna have to have it bored, as there sizes are diffrent than oem, witch makes ring NOT compatable with other pistons, A pic of that piston and Ill tell you what it is..