have u guys ever heard of any thing like that happening that quickly. I had the oil and filters changed regurally. I had a white brothers pipe, k n filter, stage 1 hot cam, and jetted. The honda shop sad the skirt on the piston came apart and tore up the cylinder and the crank shaft.

 

Yeh, if you mod them like that they blow all the time. If you ride hard it's expected. You trade reliabilty for speed and power. The main thing is to find a comfortable and affordable middle. Personnaly i think it was the K&n filter that did it....I'm sure some will will say other wise.



I think he is saying the wrist pin broke though that is normally what happens. Then the rod busts the side of the case and locks up taking out the crankshaft. The head is sometime salvagable.

Does your warranty cover it if you mod the engine like that? Most will not.

 

I have never heard of that happening before and surely not to a stock motor. Did you have it jetted right?

 

He said it was not "STOCK". With a cam and all that it would probably last one race season before the top end would need to be rebuilt. It sounds like our ran it too long.

 

A stage 1 cam is pretty mild. You don't compromise much reliability without going to a higher compression or high rev box. You should have gotten years of service. Freak occurrance would be my guess.

 

RAZOR,
Modding like he did will not make the engine "blow all the time". And riding hard does not make it "expected".
He said the mechanic said the piston skirt came off, not a broken wrist pin. Very different.
Those mods on his 400 were mild. A stage I hotcam is for low end torque.
My guess would be that your piston skirt had a flaw in it, a weak point, which caused it to break off and drop down into the bottom end and take out your crank.
Kind of hard to pinpoint the cause though.

 

I agree with RedRod...

I have similar modifications on my machine and it has run perfectly for many years.

 

LOL razor, if you dont know what your talking about then dont say anything, those mods dont hurt reliability barely any, i believe the piston was flawed, those mods dont hurt anything

 

CLICKY


heres a new post i found that sounds similar

 

last time i checked jetting doesnt have anything to do with the bottom end throwing out