Taking the piss

[Simo63]

Noel I've run with worse pistons and not had a problem in bikes ranging from RS125 that scream their heads off up to big bore 2T singles.

Of course, none of those were a high performance thoroughbred like your SWM

Honestly if I couldn't find another one, I'd run that for sure.

[NSR]

The ring is still properly supported over the vast majority of its circumference.
What do you expect to be the problem?

Just saying, I don't see the groves in the top and sides a problem, only if the ring is supported.   

[Mick D]

I have seen a lot of pistons that have suffered the scourge of detonation, most a hell of a lot worse than that before terminal failure.
Despite their fugliness, most of them would have kept going except that the parting alloys had jammed ring lands or
deposited down the sides to produce seizure.

[Lozza]

This is it with the ring on it.  The ring grove is my concern.  Although with the ring on it does not look to bad.  I will still be trying to buy a better one.

Is it a Elko or Asso Werke piston? It looks like a second. Have you tried Tony Murphy in the US for pistons?

[Davey Crocket]

Why risk destroying a barrel and what ever else it may take in it's way, it's OK for Simo to say he's used worse than that but he's talking about engines you can GET parts for, if I  was you, take the motor out (if it's not already) and take it to George McKenzie, there will be a piston that fits it, he's a genius when it comes to oddball engines....quite a few of his engines won at the Nats on the weekend (same as my fuel tanks ....speaking of which I have an ugly SWM one to do ATM). PM me or give me a ring. Shit, he might even give it some power so you stop looking at my arse!! ....there will be a cost though...at a certain event.

[SON]

This is it with the ring on it.  The ring grove is my concern.  Although with the ring on it does not look to bad.  I will still be trying to buy a better one.

Lozza I think some were hoping you might consult your crystal ball or use your X-ray vision on that piston.
If your driving past call in I have dug a few treasures out
Is it a Elko or Asso Werke piston? It looks like a second. Have you tried Tony Murphy in the US for pistons?

[Simo63]

Why risk destroying a barrel and what ever else it may take in it's way, it's OK for Simo to say he's used worse than that but he's talking about engines you can GET parts for, .. blah blah blah

Did you miss the bit where I said "Honestly if I couldn't find another one, I'd run that for sure." ??  Of course if you can find a better one then you would run that .. that's a no brainer John   

[FourstrokeForever]

If you still have your original piston, there are people around that can make pistons. They more than likely won't be forged but when in need......

[Nathan S]

I've probably told this story before, but:

When we were kids, a mate "scored" two and a half late 70s YZ80s that were literally basket cases - the engines were stripped down to the last nut and bolt, and came in a couple of old wicker laundry baskets.
While messing around with his dad's engraver one day, he picked out the crappiest looking piston, and engraved "Rodney" on the crown and both front & rear skirts.

Eventually, when he got around to putting it all together, he discovered that the "Rodney piston" was the one that matched the only good crank... So in it went, with clearances measured in millimetres rather than thou...
That motor ran like a champ for many long, hard months.

It finally Went Boom a few weeks after he sold it. The new owners were suitably unimpressed to discover the previous owner's name deeply engraved all over the piston, but the failure was caused by a lack of 2T oil, and nothing to do with the 'damage' to the piston.

[pancho]

I doubt if it would sieze with all those oil holding pock marks on the skirt. Ring lands would warrant close inspection, fit a wider ring??

[HVA61]

hey noel

why dont you investigate the possability of ceramic coating the top of the piston. i think it may be a viable proposition.

i would not be too concerned about the erossion on the side skirts.

[oldfart]

Noel ..... It's not worth the risk Bud. As Joan has explained there are other options with pistons that can be used surely.
If I opened up a motor and  it had a piston looking like that ( even though it was running fine ) I would replace it no questions asked ...... Yes it could run fine, but there will always be that doubt factor 
I'm with Doc  piston pin and bearing are replaced same time as rings.

[EML]

I was thinking HPC coating but how much damage is more than skin deep.
Not sure I would use it except if there was nothing else.

[shelpi]

yep, get it ceramic coated 1st

[Nathan S]

Corrosion works inward from the surface - the damage to this piston is on its surface.
I'm not sure what people think is going to be the problem?