Call all XR600R!!!

[Swan3609]

Ok guys I got my 640 torn apart and it was ugly.


Toasted piston


Grooved piston.


Piston pin appears to be worn out.


Now my Clymers manual said there was a decompression screw and spring here and I never had one?


Now the PO said this bike was a 640 and I havnt seen much in the way of 640 kits. Here is the piston that was in mine.




So I am looking at a new piston and some machine work. This bike ran like a striped ass cat as a 640. Should I go to a 654? Or could I re sleeve? I am stuck as to what to do now. I was really hoping it was going to be a ring but I am going to be a lot more cash then I had hoped. Any suggestions?


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[Dino3310]

Should I go to a 654? Or could I re sleeve?

flip a coin.

have you found the cause?

[Swan3609]

Originally Posted by Dino3310

Should I go to a 654? Or could I re sleeve?

flip a coin.

have you found the cause?

I have yet to find the true cause.. My piston pin was worn out and would wobble a bit, but I havnt seen anything that would have trashed my Cylinder and Piston that bad.. then again, I dont know anything... I am a bicycle guy..

And I am scared to call Arias and see how much another piston would be.. A JE 654 seams to be what I may be doing..

[elsalvadorklr]

hey dudes

damn you guys with big bore kits geeeze, settle down will ya?

us small bores have other stuff to fix too!

anywhoo

so

can someone tell me if a new pulse generator will work in an older gen xr600?

It appears my 88 is now in the famed DISCONTINUED parts list

I am now one of those special xr owners that has to do extra searching to get parts! jajaja

sooooooooooooooo

new pg old pg same?

thanks

p.s. If anybody has any input on a similar type of no start situation like mine please any input is welcome...I find it very very weird that damage would occur AFTER shutdown, WHATEVER it actually may be, electrical or other...

anybody else?

[elsalvadorklr]

Originally Posted by Swan3609

I have yet to find the true cause.. My piston pin was worn out and would wobble a bit, but I havnt seen anything that would have trashed my Cylinder and Piston that bad.. then again, I dont know anything... I am a bicycle guy..

And I am scared to call Arias and see how much another piston would be.. A JE 654 seams to be what I may be doing..

hey swan what was your problem again?

all that scratching and stuff will make a noise

I had a pro-x piston look like that after only say 1k miles, it was like that because I had an xl600r crank in there, Im assuming and it ate itself(bronze flakes everywhere) and it all got scratched up

the thing was I heard no funny noises, or felt any rattling...
the piston and bore say otherwise

good luck on the rebuild

[nikolic]

It sure looks like overheating, but what from? Probably no or bad oil. the first thing that
went wrong war probably piston pin, because it is the least lubricated. So I say, check
the oil pump!

[Swan3609]

Originally Posted by elsalvadorklr

hey swan what was your problem again?

all that scratching and stuff will make a noise

I had a pro-x piston look like that after only say 1k miles, it was like that because I had an xl600r crank in there, Im assuming and it ate itself(bronze flakes everywhere) and it all got scratched up

the thing was I heard no funny noises, or felt any rattling...
the piston and bore say otherwise

good luck on the rebuild

My problem was it was smoking really bad. Still ran well though.

One hot day she just shut off on me after flogging her hard around town and ever since then she smoked bad. The piston and cylinder are both toast and I can feel a groove in the piston pin. Would that have done anything? Or did I run her out of oil on that hot day and did it self destruct then?

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[mcma111]

Swan,

Your piston looks like a normal XR melt down due to low or no oil and heat. All to common. By the looks of the wrist pin the small end of the rod is damaged also.

[gvthnks]

Originally Posted by mcma111

Swan,

Your piston looks like a normal XR melt down due to low or no oil and heat. All to common. By the looks of the wrist pin the small end of the rod is damaged also.

Agreed. Looks like it was run low on oil. I'd inspect the head where the cam rides and everything else as well looking for metal bits. Pull the right side cover and look in the bottom of the case.

[Swan3609]

That's what I am thinking it was. I had a gasket that went bad and I kept putting off replacing and I just kept putting more oil in it. But the day it shut down on me, it was hot. 100+ and I had been riding her hard and I am guessing I hadn't put enough oil in there recently.

So assuming that was the cause. What is my next step? What all should I check out and what all should I be looking to replace?

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[mcma111]

First off where are you? Nothing in your profile.

Second you'll need to take the cylinder to a machine shop and have it checked to see what your options may be. Hone/bore to next size? Resleeve to OE or a big sleeve. What does the small end of the rod look like? Damaged = a replacement rod. How about the head center journal condition and cam 'n rocker surfaces.

[mcma111]

BTW...You'll want to check out this: http://www.advrider.com/forums/showthread.php?t=713831

[Swan3609]

Originally Posted by mcma111

First off where are you? Nothing in your profile.

Second you'll need to take the cylinder to a machine shop and have it checked to see what your options may be. Hone/bore to next size? Resleeve to OE or a big sleeve. What does the small end of the rod look like? Damaged = a replacement rod. How about the head center journal condition and cam 'n rocker surfaces.

I am in North Idaho. And I know I'll need to have some serious cylinder work. I am assuming that it's still round but just needs either bored out to the next size or resleeved.

Cam and rockers are still looking good. Same with the rod. Still smooth and looks good.

I would like to assume that it was just the piston, piston pin and the cylinder that were messed up because even smoking as bad as it was, it made no funny noises and still ran like a champ.

I will go borrow a micrometer tomorrow and start checking things the right way other then just "it looks fine"

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EDIT: mcma: That thread is awesome.. I was looking for something that walked me through all that

[benno.h]

Swan is the damage only on one side of the piston?

[mcma111]

Most damage to a XR piston is on the intake or thrust side of the piston. Depending on how much the engine is run once the damage starts you may also see some on the exhaust side of the piston. Here is an example.