Because you never know what you might find....

Can someone help me identify this piston and what may have caused this damage? Do I need to split the case to make sure no more shrapnel is down there? The cylinder walls look pretty good considering the condition of the piston.

The connecting rod has some side-to-side play but no up-and-down play.

Hoser - this is the old wheelman project if that helps with identification.

Is it a Weisco? On the top of the piston near the center it reads (as best I can tell):

2.00MM
577P8
TD

Above these numbers, near the edge of the piston, it looks like: J77F3

Thanks

That sux, going by memory Wheelmans cylinder was on its last wiseco bore
when it came back from ATV Racing, if I remember right their donation to
the Wheelman project was they rebuilt the crank with a CR500 rod and
bored the cylinder, supplied a piston kit and cleaned up the damaged head,
whole wheelman Engine rebuild should be here http://pilotodyssey.com/wheelman.htm

Looking at the damage I would say the bottom end needs to come apart, you
really need to see where that metal came from, look at the big end of the
rod and the crank bearings ball seperator .

This will get you started but search for poofkaboom and CSI here on the message board
and start reading , also look around the photo gallery there are pics
http://pilotodyssey.com/coppermine/index.php

http://pilotodyssey.com/Poofkaboom2003.htm

Look for poofkaboom and CSI on this page also http://pilotodyssey.com/pilottech.htm

Boy my site is a mess I need to put all that info in one location so I can find it heh
My page has grown to the point of out of control over 650 megs and over 650 html
files...

Sorry...

Boy Hoser - you are good - and I'm going to guess that you are 100% right (unfortunately for me). When I was slowly spinning the crank and listening carefully, It just didn't sound right and I could hear what sounded like metal balls shifting and hitting into one another as the crank was turned. I'll bet you are right and my problem is a busted up ball seperator.

Man this sucks - I hope to have this fixed in time for ECJ.

With any luck, I the only thing I'll have to do to the cylinder is give it a good hone and purchase the same piston ring combo (cause I can't go any bigger!!). Do you think this is possible?

Too bad I am good because it happen to me! mine that seperated all the way when I
roll the crank over slow I could hear the balls falling off the top and landing on the
balls that were down lower, this sux!

Look close at lower rod bearing and cage, got some close up pics I can tell alot
by color, also use a scribe or pick to rotate the cage (roller seperator) to see if
any of the seperators is missing, been there done that one too...

Pic is from wiseco catalog looks like your on last bore, only way to tell is measure your
bore and order piston, if it were mine and I wanted to run a wiseco I would CALL wiseco
and ask them if they can send you their biggest piston they have for that size bore,
their pistons vary because of production tool wear crapaol and their lax QC heh
tell them you don't want to order 6 and measure them yourself then send 5 back...

wiseco piston chart

Here is a pic of lower rod - seperators here seem to be in tact. In the second photo you can see where there was some scraping (shiny bronze color on rod).

When Hoser rebuilt my Cali motor (( Internal Combustion Engine ? )), the bearings made the same exact noise when turned Nut, sucks that it happened to you-Hoser has as old jug of mine that if you need I will do you right on it, it isnt the best but it has a bore or 2 left if my memory serves me---Hoser, you still got that or do I ???????

You should have the cylinder I still got your crank, I don't remember the details on
that cylinder and what bore it was on, did I include that in the Mudbogger CSI ?

I am not sure I see the scraping your talking about, can you draw a line to the
area on the picture?

does this help?

Thanks Mud - I may take you up on that offer... I'll keep you posted.

Marc How did you know???

I am glad you didn't take my advice , "aww it will be fine don't worry". lol


If you need help we can get that done quick, I'd blow my bike up at a sunday enduro and have it ready to go for the next weekend's race.

I can fix it, my dad is a television repairman he has the ultimate set of tools.

the scratches look kind oof weird, but not in a bad way, more like machineing marks. The picture is hard to tell but the rod looks pretty good, no heat stress signs if its tight as you say then a set of mains, seals and a top end would get you done.
Chunky chunks would be making long cut scratches on the crank(like the one in the picture on the crank itself) or worse the case halves as the crank rotates and forces the bits between the case and crank.

I wish i still had my machinist buddy, i have a hook on a guy but haven't used him yet, i heard he is good.

Yeah sorta, that is a CR500 rod its big end is slightly bigger
viewtopic.php?t=921&highlight=cr500
perhaps there is a spot where it almost touches and when the cases
are full temp and at full rpms it will make slight contact? You will tell
more when you get it apart and can look at the cases, maybe the same
metal that got between your cylinder and piston first was between your
rod and case?

Rod info I was talking about viewtopic.php?t=537&highlight=csi

Special tools in action viewtopic.php?t=495&highlight=csi

See this one, bearing oil mod I did on the wifes viewtopic.php?t=1016&highlight=csi

Heck at this point you need to read all the CSI's click on search and type in "CSI"
hit enter and start reading, lots of pictures not that much reading this will familiarize
you with the process.