Tri-z Detonation WTF?

**lovemytriz** · 11-10-2009, 10:05 PM

I found a Tri-z in my buddies barn in pieces and he said i could have it.
So after searching the barn for all the parts and the online parts i couldnt find. I rebuilt the motor,New everything.
Broke it in like im supposed too and i have been riding the

out of it for about 2 weeks.
Well today im riding the piss out of it like we all do and it just went WHAM!!!!
Motor locked up!!!!!!
Pulled the top end off and Chunks of piston and the bottom of the sleeve were ground up in the bottom end and tranny......motor wont budge.
WHAT IN THE HELL COULD HAVE HAPPENED? The connecting rod is tight,no wiggle or wabble?
anyone have a clue so this doesnt happen again after i spend 600 bucks and about 30 hours of my time. Man i wanted to cry. It always feels better when you bring one back from the dead than buying a new 4 skinner.
Anyone.....What did i do wrong?

But when she ran,,,,,Man did she run!!!!!

Got a new/used motor on the way,fresh rebuild.....what should i check before i blow this one up?

**Dammit!** · 11-10-2009, 10:08 PM

Post some pics of the carnage. Was the top of the piston white?

And welcome to the forum!

**Bryan Raffa** · 11-10-2009, 10:10 PM

they run the best before they BLOW!

**yamahaman89** · 11-10-2009, 10:14 PM

that happened to my buddy hes was riding his 250r and then he said it was running the best it ever did when all of a sudden the motor locked tight turns out the oil injector quit working post sum pics

**lovemytriz** · 11-10-2009, 10:15 PM

No the top of the piston was black. This piston is a brand new wisco. Chunks of metal were inbeded in the top.
Carnage pics comin up bro.

**lovemytriz** · 11-10-2009, 10:21 PM

pics will be tommorow, it pulled the motor,pulled the jug and just sat there drinkin a beer going....REALLY!!!!!!
It`s at my buddies farm out here in okie land...But as soon as i get her right im headed for Little Sahara State Park. it`s about an hour or so from stillwater.

**Yamaha_Rules69** · 11-10-2009, 10:24 PM

Yes it may have been rebuilt, but was it rebuilt right? All specs correct, and no measurements skipped? I dont know why it is, but I have seen numerous tri z sleeves that are cracked on the bottom. Could it have been put together with a hairline crack in the sleeve, then finally it gave out on yours? My next thought is the timing was too advanced. Pull the flywheel and look at the flywheel key. If it is sheared, there is a good chance that may have caused it to be firing before the piston was at TDC, and putting tremendous stress on the piston and lower end. This happened to my Z's original motor, and the con rod broke in half, and destroyed the cylinder, piston, and both center cases. Good luck with the rebuild, and sorry to hear about your misfortune.

**DeePa** · 11-10-2009, 10:26 PM

how was your jetting? how did you break it in? what did your intital plug chops look like? what piston?

**lovemytriz** · 11-10-2009, 10:29 PM

Good point,I did something wrong huh?

Thanks

**lovemytriz** · 11-10-2009, 10:43 PM

Break in was pretty basic from the shop manual.
with 14:1 mix,start and run no more than hafl throttle for 5 minutes,cool down.
Start and run again etc... cool down start again and run thru the power band.
cool down andchange fuel mix to 24:1. the piston was stock bore, i just honed the sleeve and i had great compresion.Plug was oily and black after break in so i changed plug and it`s been a week since. This is my first tri-z rebuild so thats why im posting to get any ideas you guys might have to share.

**Mosh** · 11-10-2009, 10:48 PM

I am gonna take 3 guesses.
Crank bearings failed from improper installation or faulty parts.
Not enough break in time, or improper jetting.

Failed water pump.
Usually when they blow like that, the problem is easy to find upon a complete teardown.

Did you rebuild the bottom end from the get go?

**lovemytriz** · 11-11-2009, 12:34 AM

Nope just a top end rebuild.Live and learn i guess

**MonroeMike** · 11-11-2009, 01:07 AM

That sucks about your engine.

Wish we could have welcomed you to 3ww, under different circumstances

**Racerguy381** · 11-11-2009, 04:03 AM

Even though you rebuilt the top end doesnt mean the lower end didnt already have a problem. I have seen it many times over. Put a brand spankin new top end on tons of compression and those poor old crank bearings just explode under the stress. How long did this bike sit torn apart before you got it? Did you make a through inspection of the crank bearings and connecting rod before you assembled the top end?

**Mosh** · 11-11-2009, 07:38 AM

Pull the stator cover and see if you can wiggle the flywheel up and down.
Also pull the small water pump cover and see if the fins fell off the pump shaft.

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Tri-z Detonation WTF?