125-200cc Piston help needed :) please!

I have a husky sm 125 03, I have ridden it for one day and it has gone bang

Here's some history, the last owner had a full engine rebuild after he blew it up, once done (with receipts) he sold it... I was the buyer, it started nice and easy and ran good, I had to run it in, I spent about 40km poodling around not abusing it, after which I slowly opened up the throttle to half and instantly made a pufffffff sound a small blue cloud of smoke and I come to a stop, as it went pufffff the back wheel locked I instantly pulled the clutch in and rolled to a stop,

After stripping and inspecting the piston inline with the port is badly scratched and the rear of the piston aswel, obviously the ring is dead with it

Obvious things I noticed...... When I stripped it down it was bone dry in there no evidence of any two stroke oil on the plug or in the bore. I have scratched the bore aswel but not so bad I think I may be able to buff it out, (the bore had only just been replated

My thoughts where, why is there no evidence of any oil I though two strokes got a bit gooey because of the oil (keeping it lubricated???) ??? It has a separate mixing tank maybe it's not feeding properly?

It had a brand new prox 6216 in it are they any good? Any known problems with them?

I wonder if anyone could shed some light on my problem? I'm going to try and buff the scratches out of the bore tomorrow and order a new piston and hope that works.

As you can imagine I'm very frustrated as its just had a rebuild , did I open it up to early ? Should I have ran it in for 100km or something?

I hope someone out there can help me with some advice?

Thanks in advance Aaron

http://www.cafehusky.com/threads/should-i-reconnect-my-auto-lube.28851/#post-259357
This thread has some advice . Mixing oil yourself seems to the go

check lower end, hows the rod look? if it ran out of oil the rod will be black and the bearing 'll be cooked with a full circumferance scoring of the piston. air leaks burn the sides of the piston @ the TF ports, and, toast the rod bearing and it idles wildy lie ging-ging-GING-GING!!! etc. did you check your plug and verify jetting- or get a pic of the plug? looks like it squeaked on lean jetting. send the cyl out for a recon. inspect bottom end for damage and do an air leak test after asbly. then, start the jetting verification process. just a note: most bottom ends will live after a minor squeak but it still places a HUGE shock load on the rod and bearing. FYI. if this is the second kaboom put a rod kit in it.

Thanks for the reply mate, after buffing out the scoring and putting In a new piston she runs fine again, after a lot of investigating I come up with the theory that oil pump wasn't working due to the lack of evidence there was oil in the bore.... Clean plug, no residue at all, the bore was bone dry...
since I got it running I put a massive amount of oil In the fuel tank to keep it well lined whilst running in again I have disconnected the oil pump line to the carb and strapped a bottle to the bike, after doing 30 km (20) miles there was not a drip of oil so this confirmed to me that it was an oil pump problem and now I will just run a straight mix and fingers crossed it will now run fine!

auto lube pumps are bad news i seized my first kmx doing 70 downhill with throttle off, cus even though the engines doing 7000 rpm the auto lube connected to throttle was only supplying idle amounts of oil that was 2cc pm wich seized the bike.

p.s. not sure if youve run rings im before but i load the engine not high revs you want the burrr sound on acceleration not the bring da ding ding... change early and load that puppy to get those rings seated.

thats only my opinion an im sure others wll have their rituals.