Page 1 of 1
think i can use this piston?
Posted: Sat Feb 05, 2011 11:02 pm
by stlrocker
haha this is what i found when i pulled this motor apart tonight. may have something to do with why it locked up.
it was cracked about half way around. it broke the rest of the way trying to get it off. no way the wrist pin was coming out. bent con. rod and broke wrist pin also. somehow the bore seems to have survived ok.
SANY0511.JPG
SANY0515.JPG
SANY0513.JPG
Re: think i can use this piston?
Posted: Sun Feb 06, 2011 7:19 am
by Jughead
A little JB weld and some Copper Wire and it'll be Good as New.

Re: think i can use this piston?
Posted: Sun Feb 06, 2011 10:28 am
by Suzsmokeyallan
Naaaahh, put scotch tape and spit on that baby and you're good to go. Why not clean it up and glue it back together as a conversation piece, OR send it to bighole john, he had a little shrine to pistons but all of his had holes, yours will definitely take centre stage.
I had bought a used RH pipe for my Buffalo off a board member a while back, it was in very decent shape and when I got it I set about cleaning it out. As I poured in some gasoline to shake it around to remove the first batch of oily residue, there was a lot of clanking inside the pipe, after fiddling with turning the pipe to getting whatever this was in there out I finally started to see what it was.
Out popped the majority of a piston in average sized pieces similar to yours but minus the crown section. I even found a piece of a ring and could just make out some of the top end pin casting section in the very tiny pieces.
It would have made one heck of a noise literally, when it left the engine and entered the pipe.
Re: think i can use this piston?
Posted: Sun Feb 06, 2011 11:24 am
by jabcb
Looks like you found another use for the this classic adhesive. Maybe its time to shoot another commercial.
http://www.youtube.com/watch?v=yVNtSjONdSw
Re: think i can use this piston?
Posted: Sun Feb 06, 2011 12:38 pm
by H2RICK
That's what an engineer would class as "catastrophic failure".....although what felines have to do with cratered pistons is beyond me.
C'mon guys, you need some strength in a piston.
I'd stick that back together with that DIY aluminum welding rod.
A little work with a file and a buff with some steel wool after the filing and she's good to go.

Re: think i can use this piston?
Posted: Sun Feb 06, 2011 4:26 pm
by stlrocker
i bought three 550s couple of years ago and sold two. kept this one cause it was low miles. i got it running but never really rode it cause it had a leaky float needle i never got around to fixing.
i decided one day to start it and run some gas through it cause it had been a while. it started right up and almost immediately. it stopped dead. no warning. no slowing down. just immediate dead stop.
the piston was mostly still in one piece except the small pieces. one of which had wedged itself between the crank and the case. no wonder it locked up.
i have another motor, but it needs crank seals so its pretty much in the same spot. it all has to come apart too. thats whats happening today.
heres the rod and the rest of it. other than the chunks of aluminum, the cases were rally clean inside.
SANY0510.JPG
SANY0509.JPG
Re: think i can use this piston?
Posted: Mon Feb 07, 2011 12:04 pm
by H2RICK
What a shame that a low mileage bike has come to such an undeserved end. Maybe SEP in the UK has a new rod/pin/bearing kit in stock.....
Re: think i can use this piston?
Posted: Mon Feb 07, 2011 1:09 pm
by Suzsmokeyallan
That first photo of the bent rod shows the next cylinder to the right with what looks like radial scoring on its left side crankwheels edge. It seems that cylinder may have lost a piston or top end bearing at some time too in its past.
Re: think i can use this piston?
Posted: Mon Feb 07, 2011 10:45 pm
by stlrocker
it hasnt come to a total end yet. ill be using parts of it and another motor. i have both motors apart now and will be sending both cranks off to bill bune in a day or two. theyre gonna pick the best parts and put together a crank out of them. its all going back together with porting, cut heads, and chambers.
heres the rest of the bike mostly together yesterday before i tore that motor in it apart. i havent really done much on the appearance yet except for the seat, fender, and plate/light.
SANY0516.JPG
SANY0517.JPG
and little work on the cases
SANY0523.JPG