What causes little dings/dints in cylinder/crank

I've got this wr400 got screwed over with the sale lots of things wrong with it. but it runs, ive noticed a few little dents in the cylinder and 2 or 3 on the crank im assuming a sparkplug or a ring went bang at some stage, just curious what it could be.

At this point the question is...Do you keep it, and make the necessary repairs? Unload it whole, or as parts, attempting to recoup some/all of your money? Your probably right...something let go, and hammered its way through the motor.

Just out of curiosity, did something tell you to inspect the internals? Or did you just go diggin'?

all the gears etc work fine as when i went to buy it but i forgot to check coolant which was none, topped up and was in header. pulled apart to replace gaskets found over heated and damaged head and some little dings in the cylinder. any ideas what it could have been? they only small but still curious


cant get any at the moment, bike is kept at a mates house..

Sort of like these marks (random photo off google) probably 10 in the cylinder and 2 or 3 on crank. and the rest of the bore and piston have no other marks at all



Those cylinder walls look scorned to sh!t. I really suggest a rebuild with freshies. I wouldn't bother putting the used parts back in and rebuild the head too. Maybe scrap it should be a thought at this point.

Dude, that motor is TOAST.


That much damage means you have to tear it all the way down and inspect everything....but I would just part it out.


Unless you bought the bike as a basket case I would go back the throttle the guy you bought it from.

Can a 450 cylinder fit? If so, will a 478 cylinder for a 450 fit? It's all of $400 for it.


If any of you bothered to read the text posted with the photo ITS NOT MY CYLINDER i got that one from google, just those 2 little dings look a little like what is in mine. im just wondering what would have caused that, was a long time before i got it as they are all perfectly flat on and piston moves freely in cylinder

The only thing that matters is specs

Mic the piston and bore

If you are out of spec, the bore is no good.

No 'dents' are acceptable!

OMG! im not asking is it okay what do i do rah rah rah im wondering what could have caused it

OMG! im not asking is it okay what do i do rah rah rah im wondering what could have caused it

Easy Charlie Tuna. Nobody knows. You should pull yours and take it to a reputable shop and have her checked out.

OMG! im not asking is it okay what do i do rah rah rah im wondering what could have caused it


Cylinder fairies with little hammers and chisels.

That's not his cylinder!! It is a random off of the internet

How much did you pay for it

the bike was 2200 and it ran fine when i picked it up just forgot to check if there was coolant but apparently not

Damns, $2200 for a Wr400. Going to spend close to that if you are going to keep the bike and pay someone to rebuild it.

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