Piston rings won't fit!

[jeffersonchristopher]

Hey guys, I hope this thread finds everyone well!
I'm experiencing the joys of owning my first 2t, first day of owning my 1990 kdx 200 I managed to push it too hard (engine had just been rebuilt) and the back wheel locked up on the a12
The inevitable had happened, so I've stripped out the top end in preparation to send to langcourts, I've bought a 220 piston to put in as I've heard you can.
The piston rings came in a pack of two, genuine kawasaki, along with a genuine kawasaki piston.
The bottom ring fits fine, I put the little wire thing behind it, when I put the top ring on it won't fit in the slot.
Has anyone ever heard of this? Am I being a complete newie?
Thanks for your time, Chris.

[Jaguar]

maybe there´s a small difference in the ring slots between the 200 and 220 piston.
are the new rings for a 200?

[Tedh98]

I've bought a 220 piston to put in as I've heard you can.

You have a 200, but bought a 220 piston for it?

[jeffersonchristopher]

It looks like there's definitely a difference, very frustrating. The rings are definitely for that piston.
Yeah I bought a 220 piston, I was going to have it bored out a bit more to fit the bigger piston and just re jet the carb.

[TheRadBaron]

Sorry to be the bearer of bad news but the 220 piston isn't going to work in the 200, for a few different reasons, even if you have the cylinder bored out and replated. Plus, the OEM Kawasaki 220 piston is a flawed design that is famous for coming apart and wrecking your motor. A savvy 220 owner will swap out their ticking-time-bomb OEM piston for a Wiseco unit even if the bike runs perfectly.
I think your best bet would be to cut your losses and get the proper 200 piston. There's a TON of information here if you search around. I'd look closely at your jetting as well. You might be lean. And it will be worth it once you get it sorted out.

[Tedh98]

Sorry to be the bearer of bad news but the 220 piston isn't going to work in the 200, for a few different reasons, even if you have the cylinder bored out and replated.

It will take more than a bore/replate, but you can turn a 200 into a 220.

[TheRadBaron]

Do you mean swapping an entire 220 top end onto the 200?

[Tedh98]

Do you mean swapping an entire 220 top end onto the 200?

No, you can take a 200 cylinder and head and make it a 220. But of course not with an OEM 220 piston.

Gorr will take a 200 and turn it into a 225.

[jeffersonchristopher]

Thanks Rad Baron, I wasn't aware of that, but every day is a school day! I paid £90 on ebay for the piston, piston rings, fmf silencer and full engine gasket kit, so it wasn't a complete waste of money I suppose.
Ted, I have also heard this, it was my mate that mentioned it, I thought it would be quite cool to do it.
I think for the sake of ease I going to forget about the conversion for now and just get a wiseco 200 piston.
Can you tell me what the standard size is please? Is it 66mm? Cheers.

[KDXGarage]

66mm is standard.

To whomever was talking about converting a 200 to a 220, did you read that he had a 1990 model??

You can't just bore and plate an "E" model like that!

[Tedh98]

I missed that he had an E series.

Is there not enough aluminum to work with? Or do you have to go to a sleeve if you wanted it done?

Or is there something with the head or powervalves that creates a problem when going to a 220?

[jeffersonchristopher]

Sorry for the late reply lads! Duty calls...
I'm probably being a dunce, yes it's an e series, I've sent that piston back and managed to get a refund.
I'm just going to fit a standard 66mm now, ad I feel I'm out of my depth!
Currently trying to get thisbloody exhaust valve out past the rod! Any hints? Cheers.