Piston and Cylinder Diagnosis

[Lane]

G'day,

Had a quick top end tear down today of the 3XV i bought recently that "needs new rings", turns out the rings were in a plastic bag in the boot and the piston, heads and barrels had been re-fitted.

The bike has 19 000kms on it and is all stock (I haven't checked the jetting yet) But the spark plugs are 8's, I assume 9's are the recommended plug and i'm sure contributed to the engines demise as well as worn rings.

There is no detonation marks on the piston tops or inside the heads.

There is a light deposit of piston alloy on the Nikasil that should clean off and there is very light scouring that can be felt with my fingernail.

The first two pics are the bottom cylinder, the second two are the top cylinder.

The top cylinder has more scouring than the bottom cylinder and is more widespread than the just around the exhaust port.

On that last pic of the top piston you can see where the bottom rings land has chipped away slightly.

As the rings were in a bag i measured each ring in each barrel and both combinations were all between 0.45-0.52mm.

I will be getting these ported and re-plated with new top-end etc but hoping to hear your thoughts and diagnose the cause before i go any further.

Many thanks

Chris.

[Paul]

Lane
I cant believe both went
it has to be a cold seize, unless something stupid like he ran out of oil
i am only guessing, the pro's will be on the scene shortly
what bad luck
your rings are on the outer edge of their limit, i use new rings to measure bore, i dont have any other way, as you are getting them replated all what i said doesnt matter, but do check autolube and water pump and pipes etc.

[EEKNOWS]

Could be a cold seize by the prior owner and have ran it after you bought it.

[Lane]

It's hard to say, the bike has tyres with 95% tread left from mid 1999 with the old 3 digit tyre date code and the tank was one of the rustiest i've ever seen!

The oil tank is dry as is the coolant but this has been sitting for well over a decade.

[Lane]

Crank seems good though, only about 1.2-1.5mm lateral movement at the little end.

[Paul]

Lane, you gonna flush that ol crank out nicely?
May as well do the seals at least, have a look at mains, also easy to replace.

[Lane]

I will when the time comes.

Also i forgot to add, the head gaskets had remnants a sealant on it as well.

[Paul]

Lane
Are you related to the chap with the 3ma rd350 in PS this month?

[Lane]

Lane
Are you related to the chap with the 3ma rd350 in PS this month?

Not that i know of. Why?

My dad moved here from Manchester when he was 15, we have family there but I've never met any of them.

Assuming it's an English publication?