inside of my KXT engine (pics)

[ange]

Well, my compression was ~30lbs under the minimum spec.
So I decided to tear it open. Appears to be the original piston (only marking are on the inside, "Japan", "ART", "2" and some other in-decipherable stuff. Lot's of carbon on the top of the piston, but strangely NONE on the head in the combustion chamber (has someone been in here?). There is no detectable up/down movement in the rod/crank, so things seem to be OK there...

As you can see, the piston has lots of scoring on it's sides, the bore wasn't too badly scored, but you can feel a ridge at the top.

Anyway, what causes the scoring on the side of the piston? Just wear in the rings/piston causing slop so it bounces around in there?

[J.D.]

Not related to your post, well sort of, but I too would like to know what these "ART" pistons are. I had one in my Tri-Z. Is this old-school aftermarket pistons or what?????

[TeCaTe_MaN]

when i tore my Tecate engine apart there was alot of carbon on the piston but not hardly any on the head...it had me wondering too... ;) not sure why.....

[ange]

A quick internet search finds our answers...

http://www.eric-gorr.com/techarticles/twotopweb.html#The%20Piston

Wow, ALOT of info in there. I guess ART makes the OE pistons for lots of JAP bikes.

[Tri-Z Pilot]

Yeah alot of stock oem pistons say ART on them, the one in my blaster and tri-z did.

[Dan Tenn]

Nice info Ange. I just printed it out to browse through before doing another top end.

[JMiller]

My 87 kxt had a stock ART piston.

[Jeb]

Great Info Ange!

I have a stock 84 piston, new in the box. Let me research what it is and it's size. I believe it's not oversize. If I can use it in my 86 I'll keep it. If not I'll sell it at a savings over Kawasaki. :-D

[200x Basket]

Great Info Ange!

I have a stock 84 piston, new in the box. Let me research what it is and it's size. I believe it's not oversize. If I can use it in my 86 I'll keep it. If not I'll sell it at a savings over Kawasaki. :-D


if it is the correct size, it will fit the 86. the pistons are the same

[Jeb]

Thanks Basket. I was thinking they were. Seems like I had checked into it a few years ago. I'm pretty sure its not an over-size.

I need to save it then.

[200x Basket]

the scoring on your piston could be from several reasons.

1. it looks like it was run hard before it was allowed to warm up. the piston and the cylinder do not heat up even and this causes and interference problem. i learned that the hard way :(

2. the piston could be so worn that it was rocking in the bore. that will cause it to wear like that and eventually break the skirt off.


you most likely will need to replate your cylinder but i would take it to a cycle shop to be sure. you can clean the nicasil liner with an acid (not sure what type) to remove any aluminum that is stuck to it.

hope this helps
chris

[KASEY]

as bad as that piston looks to me i would do a double take on the main bearings!!!! it looks more like contanination to me,,,,,,,,,

[Curtis-Tecate3]

Here is my 2 cents...
I dont know if you just bought the bike but for sure someone was in the motor if the head (combustion chamber) is that clean. I assume that someone opened it up, cleaned the carbon from the head, then pulled the cylinder only to discover the piston / cylinder damage. Upon finding out that it was going to cost more money than they wanted to spend they just simply reassembled it and sold it.

Judging by the piston alone I can assume that the electrofusion plating is shot and therefore you will need to do one of 3 things. Buy a new cylinder, Re-Plate the damaged cylinder or install a boreable steel sleeve in your cylinder. This is of course in addition to replacing the piston, rings, wristpin and upper rod bearing.

Curtis.

[slippy4]

what is the deal with the plating in the tecates? what is it supposed to do and why cant you just bore it and use a aftermarket piston without replating it?

[KASEY]

i don't see anything wrong with the head,,,,, i just opened up my 86 and it was as clean as that one......

[Trikeaholic]

the scoring on your piston could be from several reasons.

1. it looks like it was run hard before it was allowed to warm up. the piston and the cylinder do not heat up even and this causes and interference problem. i learned that the hard way :(



hope this helps
chris

Thats what I told him "cold siezure" that is what I think. I would take it to a shop and have them check the cylinder for perfect round, if it checks out, have them remove the aluminum build up. It is my understanding that the plated cylinders DO NOT wear egg-shaped like an iron sleeve, that would be the reason that they are being used now?? I hope its easily repairable, I want to see this trike done!

[JMiller]

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