hey everyone i was hoping that someone in here could help me. im doing a top end on my 1976 yamaha it 400 and was wondering how the rings get installed my rings are NOS yamaha and have no markings for up or down. they do have a taper at the end of them. should i put the long point of the taper to the top or bottom or does anyone know the right way to istall these?

I'm not sure exactly what you're saying about "taper", but in general the rings will have markings on the top surface near the gap.

(One exception is sometimes L-shaped dykes rings but it's pretty obvious which way they fit)

I looked at some IT400 rings on ebay. 

I'm not sure of your experience so I'm going to mention that two strokes almost always have the rings pinned in place so they can't rotate in the grooves.  

Look at those pins in the ring grooves.  It should be very obvious how the "notch" in the ring end needs to be placed to clear the pin as the pin should be offset either high or low in the groove.  

Keep in mind that Yamaha rings fit Yamaha pistons so if you don't have an OEM piston, OEM rings probably won't work right.

My guess is by taper you mean the step. Step goes under the ring peg but shouldn't be able to fit it with step up or would butt against the peg rather than under it. Sorry  I see MarkT had it under control. All good. Welcome too from NZ as looks like you're new to the group--enjoy your time here.

Talk about confusing!
Speaks of taper and means end gap notch for ring pins.

Mark is correct, it should be obvious as hell.



Anyone know if these OEM rings are 1/2 keystones on a IT400? Top and Second?

I'm sure--in my own mind--that IT400's have parallel rings not a tapered top surface ie "keystone".
I'm talking the ring surfaces as they fit in the ring groove as some models have 'keystone tapered top' to help stop sticking in the groove, or other obscure yamaha reasons.
The "step" as i call it, is how it's cutout to fit under the ring peg at the ends.
All good 'frequent flyer 71', we all have our own terminology when we're not sure.

i would post a picture of the piston rings to show you what i mean but site wont let me post it!!

Is your question answered?  

To post links or photos you need to have at least a dozen posts and you must use a third party like Imgur or Google photos and post the link here.

I wonder if you private messaged a photo to one of us, then we couild post up here for you.
Was just a random thought that may run into the same problem.
I just link through google photos but maybe you're caught out which ever way you go.