T20 piston ring compressor

doug rooney · Post by **doug rooney** » Thu Jul 16, 2009 2:49 pm

What to buy and where to look? Already destroyed a piston by trying to do it by hand. Thanks

Post by **Suzsmokeyallan** » Thu Jul 16, 2009 6:39 pm

Doug normally you lube the piston and rings with some oil then align the pins to the ring ends and slide the piston up onto the taper at the bottom the cylinder.
Carefully getting the top ring onto the wall from the taper then the lower one by pressing at the sides with your fingers.
You do not want to turn the cylinder or force it in anyways as this will definately break an end of a ring.
What happened to your piston you damaged..

doug rooney · Post by **doug rooney** » Thu Jul 16, 2009 7:31 pm

Thanks Suz,
I may have done it wrong. I "thought" the piston had to be on the rod end and brought the cylinder down onto the piston. No??? Tried very carefully to hold the ring gap tight at the pin but the end of the ring wandered on top of the pin in the process. Worried about it at the time as that cylinder went down VERY hard but seemed ok once it was down. Tore the engine apart yesterday due to starving the other side of oil and trashed that one also. Just noticed today what I thought was the "good" side has a very bad gouge in the cylinder. Since they are already 0.5 over, I'm hoping and praying there is enough there yet that a 1.0 boring will do it. If not, that's the end of them right?

edit: Just went out and looked at the piston and cylinder again. I now see there should be plenty of room to get the piston connected to the rod AFTER I get it started in the chamfered bottom. I can then make sure it's in there right. Once again, I got "should" all over myself. Live and learn.
Thanks again

Post by **Suzsmokeyallan** » Thu Jul 16, 2009 9:28 pm

The piston is supposed to be on the rod with the circlips in before you start and if it helps you, preferably supported so it cant twist back and forth.
If you need some extra help you can make two small blocks of wood to lay front to back on each side of the rod along the base gasket portion of the engine.
These can help hold the piston steady and level, also make them just tall enough so they rest on the piston skirt and place the piston about half ways up its total rod travel.
Having the piston steadied is so you can concentrate on getting the rings up and to the cylinders taper while it sits square to the cylinder.
Then as you lower the cylinder onto the piston, carefully move it down as you check and recheck the rings location to the pins and that they are sitting flush in the grooves ALL the time.
If you need some extra help with a ring push guide, using one narrow side of a regular clothes peg as an assistant can help you to keep the rings flush in sections where they appear to be pushing outwards.
Always watch the way the ring sits in the groove as you guide the cylinder down by looking at the ring to piston wall protrusions.
Once youve got the top ring just into the cylinder you would follow the same procedure for the lower one thats now entering the middle of the taper.

doug rooney · Post by **doug rooney** » Fri Jul 17, 2009 5:16 am

Excellent Suz, got the correct procedure now. Thanks so much.

PS: Do the base gaskets require gasket sealer?

Post by **Suzsmokeyallan** » Fri Jul 17, 2009 6:27 am

For base gaskets on these old Suzukis i never saw the factory put any sealant on them, and as long as your cases are true and flat you should not need any.
Ive always put some oil or grease wiped onto both sides of the gasket which has never been a problem for me but its a personal choice of the engine builder.

Coyote · Post by **Coyote** » Fri Jul 17, 2009 6:50 am

I am not that familiar with a T20, but I like to use Permatex Anti-Seize Lubricant on base gaskets. It does a good job of sealing them and the real plus is the gaskets will not stick on disassembly. Some of this brushed on retaining threads will help you get more accurate torque readings as well.
I prefer the copper based spray on stuff for head gaskets.

doug rooney · Post by **doug rooney** » Fri Jul 17, 2009 1:49 pm

Thanks Yote. More good tips. Don't see how it could hurt to seal them and like the idea of them not sticking although this will be the last time I take it apart. LOL! Yeah, right!

BTW: The 2 head gaskets? Hardly on the bike for any time at all. Do you spose I can re-use them?