Tore apart my Tri-Z with pics

[1984kxtTECATE]

Well this is the first 2 stroke engine I have ever took apart, i was a little worried but I did it fine, I have some pics of the componenets and of what happened.

A little storie behind it, we were at Florence for fathers day and we were topped out on the flats, so I blipped the throttle every now and then to keep things lubericated. About 3/4 a mile down It backfired and quite, so I pull the plug and somthin came up and slapped the plug so there was no gap, my first assupmtion was the piston itself did that, but I later found ou that the tri-Z's had a squish band design, so that was out of the question. Turns out peice of the piston skirt broke off got into the cylinder bounced around and nailed the spark plug, I later found the 2 chunks off almnium responsible for this in the pipe. Looks like I was runnin to lean on my air/fuel mixture, I notced the piston is pretty discolored on the sides from heat, than agian it could make sense becuase the rings are always constantly transferring the engine heat to the cyclinder walls, and seeing how the exhuast port is always the hottest the water jackets are the thickest there and the intake port is always the coolestso it makes sense they are lookin hot there but it still looks like too much. Pics of my day....

The two chunks of allmnuim, that makes me mad

Cylinder wall is in great shape, no grooves, I will get it honed jsut to be safe


Here is the severe heat, the rings are seized also

Note the broken peice of the skirt in this pic below, thats were they came from

Here is the top of the piston, you can see all the markings those little almnuim peices left

[BigGreenMachine]

Harsh man, looks like a mess.

[LonesomeTriZ]

That is not too bad. I have seen worse.

[Louis Mielke]

I had a CR80 that had two bits of aluminum in the cylinder like that....course the cast parts around the cylinder skirts also broke off and trashed my cylinder. Turns out the thrust washers on crank went out and decimated everything and I had jsut done a top end on the bike too, less than 2 hrs of run time......now I'm a crank nutt...if I even sneeze at a 2 stroke crank wrong I'll get it rebuilt....better just a bore and piston than a crank new cylinder and piston....
Learned that lesson the hardway...CHECK THE CRANK! lol

[1984kxtTECATE]

I had a CR80 that had two bits of aluminum in the cylinder like that....course the cast parts around the cylinder skirts also broke off and trashed my cylinder. Turns out the thrust washers on crank went out and decimated everything and I had jsut done a top end on the bike too, less than 2 hrs of run time......now I'm a crank nutt...if I even sneeze at a 2 stroke crank wrong I'll get it rebuilt....better just a bore and piston than a crank new cylinder and piston....
Learned that lesson the hardway...CHECK THE CRANK! lol

Thanks for the tip, tommorows project, lol