Piston Ring Installation

[tatchity]

Hey all, year long lurker, first time poster. A genuine thanks to all of you who actively post, this is a fantastic community and resource!

I have a question regarding piston ring installation.

I have an 86 spree, and I am installing a 44bbk from Taz. Quick piston ring install question. How much "play" should an installed piston ring have? Is there a way to confirm that I have hit the piston ring groove? I

I have consulted "MySpree" and "Noiseguys" guide to piston ring replacement, and it has been super helpful as a general guide.

I broke a set of rings the first time I attempted to put the cylinder on, and I figure I should take a minute and talk to you guys before I try again.


Again much thanks for your help now and in the future!

Tom

[Mystic]

when installing hte rings you want to spread it apart at the gap gently and try to get the opposite side to fit over the piston then slide the gap down. You have a lesser risk of breaking them if you work evenly from one side to the other

[tatchity]

Just to clarify, I actually broke the rings attempting to slip the cylinder over the piston.

I was able to get the piston on the ring with great effort and patience

[swimmingfree]

there are some stops in the slot were the ring go you have to make the ring end gap hit there ...
swimmingfree

[tatchity]

Follow up question now that I have taken a look at these rings...

If I install the rings properly, will I be able to "spin" them around the piston?

[Bear45-70]

Follow up question now that I have taken a look at these rings...

If I install the rings properly, will I be able to "spin" them around the piston?

Yes and no. Yes, they will usually move around the piston BEFORE install. But you MUST align the ring ends with the alignment pins in the ring lands (grooves) or you will not get them into the cylinder or you will break the rings. The rings can NOT rotate while in the engine's cylinder.
.

[breaze]

Once you line up the pins with the gaps, you should be able to compress the rings into the grooves fully with your fingers (grooves should be cleaned out).
Also, when sliding the cylinder on, you should be able to compress the rings with your fingers while slipping it on - there are two slots on either side of the cylinder where you can place your fingers.
One last thought, slather them with oil first.

[speedy25]

2 strokes HAVE to have the ring ends "pinned" so they cannot spin around so the ends dont get snagged in a port. Make note of where those pins are. Typically they are on either side of the intake port. Construction of some pistons have the pin in the center of the ring land but most are offset. Make sure the ring is in the right orientation so the ends wrap around the pin. Typically this will be when any writing on the ring is UP. Carefully squeeze the ring into the groove making sure the ends are fully in the groove as you slide the cylinder on. You should be able to slide the upper one in. and then with a little work the second one will slip through too. If it doesnt go on easily you have something wrong!!

Personally I say rings dont need the extra lubricant for startup, BUT the piston skirt does, so add some of your favorite 2-stroke oil to the skirt.

Dont forget your base gasket!

And another thought on top end work... NEVER reuse wrist pin clips. Used ones WILL fall out. The cheapest part can make the biggest expense.

-SP

[Mystic]

I dont necessarily agree with "NEVER" reuse a circlip....I have reused them plenty of times and I have never had a clip come loose I also take care when removing them so they arent completely bent out of shape so that I can reuse them. I guess it all depends on how you do it.

[speedy25]

I have sold new top ends to people who didnt believe they should spend another 69 cents. Some get lucky. Some dont.

I just put my engine back together with a piston kit from chop-chop. I have to sympathize with the OP a bit. Those rings were STIFF and it took three tries to get the cylinder on. I normally get them on easily by lining up the pins and sliding the cylinder on in one pass.

-SP