PDA

View Full Version : Ouch!


400exRacerX
03-22-2002, 07:22 PM
Hey,

I just got done helping out a good friend disassemble his 400 to install a 416. He needed a rebuild bad since he burnt oil like crazy. Well when we popped the cylinder off the piston we weren't expecting it to be this bad. His piston is on the left and my stock piston is on the right. Has anything this bad happened to any of you? I couldn't believe my eyes on how bad it was.
400exRacerX
03-22-2002, 07:23 PM
Heres the other side.
400exRacerX
03-22-2002, 07:24 PM
And heres the inside, his looks burnt.

What do you guys think could have caused this much damage?
trx400ex
03-22-2002, 07:31 PM
is that piston for sale??? jk but hey, we got the same keyboard!!!!!!!!:blah
Guy400
03-22-2002, 07:50 PM
I've only seen 2 pistons in worse condition than that one. One was in an all-aluminum Keith Black Funny Car motor (something happened and the cylinder went lean and the piston melted in the cylinder) and the other was when a connecting rod let go in a small block Chevy (use ARP rod bolts for those rebuilding car engines) and it threw the piston up into the head and the valves did the rest.

In regards to your friends piston, were all the bearings good in the rod? I can't really tell but it looks as if the scuffs don't run the entire length of the piston but start about 3/4 of the way up and continue on down. Looks as if the piston was rocking in the bore and he was getting some nice sidewall loading. Either that or he found out where his little sister deposited the missing sand from the sand box.
400exRacerX
03-22-2002, 08:13 PM
Yeah, I seen worse in my friends cr80 were the hole piston actually exploded into a million peices but thats a 2 stroke. Heres a better pic. We do ride in the local sand pit often. I also noticed while disassembly it the wristpin was extremely hard to get out of the piston. The rod also has some side play in it.
400exRacerX
03-22-2002, 08:14 PM
.
honda350r
03-22-2002, 08:22 PM
Big deal! So it seized,that is what you get when you don't let them warm up before you thrash on them litttle engines!! Nice picture though! Jim
trx400ex
03-22-2002, 08:26 PM
looks like he needs a new rod....

http://cgi.ebay.com/ebaymotors/ws/ebayISAPI.dll?ViewItem&item=1814433701&r=0&t=0#BID1
400exRacerX
03-25-2002, 02:37 PM
Well we found out today that the crank and rod are shot. So hes looking at some big bucks now.
EX 80
03-25-2002, 03:29 PM
Did he change his oil often?
Blysster
03-25-2002, 04:22 PM
did he have any oil in at all :confused:
400exBro
03-25-2002, 04:47 PM
Just recently i had a problem where my drain bolt on the crank case vibrated out and all the oil ran out and i almost seized it up, i heard a loud knock from the valves and shut her down, luckly it didn't seize up, but if that happened to you and it didn't seize up i should check mine too, right??
thanks
Bro