Hi all,
I got a Wiseco Std piston and rings for my DT3. It did not come with circlips. I put the Yamaha clips back in....Now I don't feel good about it.

I can't seem find anywhere what the Wiseco size is for the correct ones for this piston. I have searched CW14-21 and none say they are compatable.The Yamaha clips are very stout and fit in the grooves but they don't seat far enough in. I have the cylinder back on but is not bolted down. I can still redo everything if needed.
 

You might try calling Wiseco. 

They used "Spirolox" instead of wire circlips for many years...  Groove is very "square"....  using the wrong clip could be disasterous.

www.smalley.com/retaining-rings/spirolox

I don't have anything to add regarding the circlip, but I'm interested in how the Wiseco piston works out for you once you get it up and running. I found a new Wiseco (1st over) in my DT3 when I bought it. 

Thanks for the link. I measured the old piston hole, a Yamaha, and it measures ~16mm so I ordered a 2 sets of Wiseco Circlips 16mm CW16's.$11. I think its going to be ok when I get the these clips installed. This bike seems like it was thrown together. Wrong hardware every where, missing clutch plates, the piston rings look like they don't go with the piston that was installed, took forever to scrap the old gasket stuff off. In general the bike seems to have very low hours, the frame and engine numbers match but it has been heavily molested over the years.
 
 

Be very careful.  Inspect the grooves carefully.  Are they machined "square" or "rounded"? 

Almost certainly those are not the correct clips because the pistons do not have the "notch" to allow the clip to be removed after they are installed.

If groove is machined square, you'd likely be better off with using internal circlips...  the kind with the little holes for special pliers...  with the gaps straight up or down and sharp edge out.  Again, contacting Wiseco is the best thing to do IMHO.  www.arconring.com/metric-circlips/int-me...rclip-d1300-din-472/

Other things to check with early Wiseco is ring gap.  They were a true performance piston and expected the installer to check and file the gaps to spec.  Many people didn't and this caused siezures.  I remember always having to file the gap on a Wiseco vs. a stock Yamaha ring that always seemed to have the gap on the large side of the spec.  New Wiseco pistons have larger gaps now which is not as good for performance but better for them because people don't read or follow instructions and then blame the piston when the problem was the mechanic.

And of course, correct piston to bore clearance is important.

Notch that comes in Wiseco piston when they use wire clips:
 

I've seen the damage that losing a clip can cause.  In my opinion, you'd be better off throwing that piston in the trash if you can't find the correct clips.  It will be cheaper in the long run.  I've said enough.  It's your bike. 

Whoa.. thanks for this info.. it does not have the notch. This looks like a really old piston. I need to rethink this stiuation. I don't want to seize it.

Thanks very much for this information and the link! 

Losing a clip is almost always much worse than siezing.  Cylinder and sometimes head, cases, and crank can be destroyed.

Look at groove with a magnying glass...  groove for wire clip will be rounded like a u to accept the round wire...  internal circlip or spiral lox groove will have sharp, square corners in bottom of groove...  It's pretty easy to tell the difference.

You'd be very lucky to have found a DT3 still on standard bore after almost 50 years. Where was it hiding.

That's the thing with this bike. The underside of the frame is hardly scratched and the bottom end of the engine is very clean. I don't think the cylinder is the original but it is in very good condition. The sprockets seem original and still look pretty fresh. I think the tires are original and they don't have much wear. They are matching Dunlops. That poor bike has had a strange life..