Tri-z Piston Failure

[Just-Tri-It]

Well my Z quit running. Thought it was a carb. problem at first. When it showed no compression while kicking it I pulled the plug and covered the plug hole with my finger. Engaged the kicker and nothing. Not even a burp. So I pulled the cylinder and 'say it ain't so!' Found this hole. I checked the water pump and sure enough it was failing. But is water pump failure enough to cause a hole to be burnt in the cylinder. The piston was .030 over. On its second bore. I had ridden the bike only twice before the failure with about an hour total time. But only about 15 minutes on the next day at the time of the failure. Anyone else ever have this happen?
Thanks

[code200k]

to me that doesnt look like the pump failure caused that,which would be heat seaize no?to me that looks like a plug/detanation issue.PLus not enough for the bike to over heat
EDIT: got any pics of the plug?

[younganreckless]

^ yes tht is exactly what I was thinking, my friends tri z did the same thing but it wasn't the water pump it was plug detenation

[Just-Tri-It]

to me that doesnt look like the pump failure caused that,which would be heat seaize no?to me that looks like a plug/detanation issue.PLus not enough for the bike to over heat
EDIT: got any pics of the plug?

The plug was not damaged. It was medium brown and a fairly new plug. I had put a new one in when I got the bike and chopped it a few time. At time of failure it was med. brown and no damage. I'll try to get a pic.

[Just-Tri-It]

^ yes tht is exactly what I was thinking, my friends tri z did the same thing but it wasn't the water pump it was plug detenation

What would cause that? Bad gas. It was 92 with 4 ounces to a gallon oil.
I believe they use to race the bike some. But it had sat up about 4 years before I bought it.

[code200k]

What would cause that? Bad gas. It was 92 with 4 ounces to a gallon oil.
I believe they use to race the bike some. But it had sat up about 4 years before I bought it.

allot of this new gas has so much octane it that it kills these great two stroke motors from all the octane.a snowmobile mag explained it all in a good way

[fabiodriven]

allot of this new gas has so much octane it that it kills these great two stroke motors from all the octane.

That doesn't sound like it would make sense. I'd like to see that article.

[thestud25]

Plug is way to hot. Ie, running a NGK b6 or 7es instead of a b8 or b9es. What plug were you running?

[MTS]

Looks to me like a Tad to much compression and To low an octane fuel... I.E pre- ignition..that sucker got hot in a hurry...

[Just-Tri-It]

Plug is way to hot. Ie, running a NGK b6 or 7es instead of a b8 or b9es. What plug were you running?

Running an NGK 8. The standard. It may have been a hotter one in it before I got it or when I first got it. I don't remember what it was. I put a new one in it to do the chops. It may have been about ready to go when I got it.

[Dirtcrasher]

allot of this new gas has so much octane it that it kills these great two stroke motors from all the octane.a snowmobile mag explained it all in a good way

I've read ethanol affecting 2 strokes but not octane..........

New gas, more octane??

[TECATEMATT]

8s aren't that hot of a plug? What kinda gas mixture are you running maybe a little to lean? Look on the bright side it could be worse, this is what I did to my old man's piston few years back on his tecate.

[Chazz of Blades]

Well, when you think about it pre-det is like striking the piston with a small .



Octane lengthens the burn time of course, making the fuel harder for the engine to burn, thus lengthening the burn. Low octane gas equals more, and faster, bang than higher octanes. I always run 89 octane in everything, and if it runs fine, with no pre-det, or anything, it's fine with that octane. Higher octanes are really for higher compression motors, which would explain the "harder to burn" thing.


Overall I'd say you were SOOL my friend.

[Just-Tri-It]

What about an air leak around a crank seal? The plug was not whitish though. Medium brown. Or if the previous owner was using racing fuel or additives?

[Billy Golightly]

Closeup macro picture of the plug (With the threads removed if posible?)