Suzuki 2 Strokes

Hi

A search of the archives got me some good info, but some conflicting, so I thought I would throw out a request for some help, info, clarification, etc.

GT380 L model (1977). For Canadian import. Sitting in a garage since 1978. Wouldn't turn over so I pulled the barrels. Figured I'd replace the rings. I have a fiche and it shows the same ringset for all years. Part number 12140-33011. Have gotten two sets of these but looks like both could have been messed with. Here are my issues:

Original Rings

Top ring -Keystone. Tapered outside to inside (i.e., cylinder side to piston side) Outside thickness 1.46mm Inside thickness 1.3mm
Chrome plated on cylinder side

Bottom ring - non Keystone, but tapered outside to inside 1.46 - 1.3mm Chrome .

Replacement Rings

Upper - Keystone. Tapered outside 1.46mm to inside 1.3mm Not chromed

Bottom non Keystone, not chromed, not tapered outside to inside 1.46 mm outside and inside measurement

The replacement bottom rings will not fit, as obviously the ring groove is tapered and the ring is not. A second set of rings I got were all keystone, and fit in either the top or bottom groove. Both sets of ring were in an open package, so who knows what I really got (but I put all the rings in cylinders and the ring end gaps are all right in spec.)

And yes, I am trying to fit the rings with the letter markings 'up'.

Questions:

I've seen reference to the use of all keystone rings for the K model. Did Suzuki go to all keystone at some point? Or can I use all keystone rings anyway? Any negative impact on compression?

The stock bottom rings were non-keystone, but were tapered. Have not seen any reference to non-keystone, tapered rings being used in the 380. I suppose they may have used some other rings they had to use up stock????

Stock rings were chrome. All the replacements I have are not? Any issues here with using non chrome rings?


Any help at all would be GREATLY appreciated.

Paul

Welcome, Paul -- you've tapped into one of the Legendary Great Suzuki Mysteries with this one.

H2Rick, one of the mods here, has the definitive reference guide to which pistons and rings were fitted to the bikes from the factory, but of course, that doesn't take account of previous owners that may have worked on the motor ... I can't find it just now, but hopefully Rick will be along soon

EDIT: here you go .... http://www.ozebook.com/compendium/suzi/ ... istons.pdf" onclick="window.open(this.href);return false;

Certainly on the later models (after the 'L', if I remember right), the rings are all keystone and all chrome. Note that chrome rings don't look shiny and chrome-like.

Thanks a lot for the info. Always good to know that I've tapped into a Legendary Great (insert marque here) Mysteries... I'm new to the Suzuki triple thing - obviously. And new to the ring thing.

I had seen the chart put together by H2Rick (thanks for that, Rick) and the info was consistent with a Suzuki service bulletin that I dug up - all keystone, K and later. So I guess I'm good to go with the keystone rings I have. What got me questioning this was the presence of non-keystone bottom rings that have a outer to inner taper. At this point I'm still curious about it, but knowing that factories don't always do what they are "suppose" to do, I'll just let it go.

And thanks for the comment about chrome rings being not shiny. The ones I took out WERE shiny. Can I presume that they were once not shiny but were polished by movement in the cylinder????

Paul

Sorry, what I meant by "not shiny" is that they don't gleam like new chrome on a cosmetic part (like a wheel rim or similar), they often look a little dull ... I've had a few NOS genuine Suzi ring sets and the metal just looks like steel, it isn't particularly shiny or bright. That could be age-related dulling, however.

As long as you check the end gaps are within spec and as you say, fit them with the lettering upwards, you should be fine!