Replacing Piston Rings

[HENRY]

Hi, can I just easily replace a set of new piston rings without doing any honing or other work please?

I broke one whilst putting the head back on. Engine has done between 15,000-20,000 miles.

[DAVID THOMPSON]

take the cylinder off and give it a quick hone
dave

[Puffs]

IMO, if you just broke a ring &everything else is fine, in principle just replacing all rings would do. If there is wear, better all rings at the same time, than just a single ring (but if you would have a suitable spare ring lying in a drawer, you could just use that).

IMO honing on a 2T is more something to recover from a scratch or some other damage, but it is an option. However, after 15-20k miles with an ETZ125 I'd have a good look at the clearances (see manual) and consider a re-bore and/or a new piston.

To prevent similar problems in the future, take some sandpaper and make the entry into the cylinder very smooth, so that the rings slide in easily. Clean well after that. Lube bore & rings, and most of all: make sure the rings are positioned correctly wrt the slots in the piston. Help entry with your fingers, compress the rings in the slots below the overflow ports, while keeping them properly positioned over the slots.

[HENRY]

That's a great help, thank you.