getting jugs on over pistons

I'll soon be putting new rings on the SR. Are there any tricks or recommendations for getting the jugs back on?

Clymer suggests making a wooden tool for keeping the piston from dropping while reseating the cylinder jugs. Has anyone tried this?

I'm thinking that I'll start with the center two pistons, holding the rings into place while sliding the jugs down, then remove the wooden retaining tool and letting the inner pistons down before moving on to the outer pistons.

Is that a decent way of going about it? Is it possible to do this by hand? Are there "must-have" tools that would keep me from installing the rings and replacing the jugs entirely by hand?

I'm a little concerned about getting it all back together without scratching the cylinder walls or generally making a mess of things. I'm probably too paranoid, but I don't want to find out afterwards that there was an easier way, or something that I did wrong.

Chet, you can do it without a ring compressors, particularly, if it is a standard bore, as it will have a "lead-in" diameter for easy entry of rings to bore. An extra pair of hands are always a help. I found the two bits of slotted wood handy sometimes.
I assume you have gapped all the rings to spec.

Make sure you have the base gasket and dowels in position starting (hard to put on after). I get the two middle pistons in first, one of the hard parts is to keep the configuration of the gap position. You tend to say near enough! and that's OK!
I have utilised a golf tee to finally click the rings in. You can do it! Just be patient. Easier said then done.

Regardz

Garn wrote:

Make sure you have the base gasket and dowels in position starting (hard to put on after)

The voice of experience always speaks the loudest:laugh: :laugh: :laugh: Good one, Garn.

Hi,, now my english is not 100%, so Im not sure what you mean by "jugs"?

when I install cylinders on a 4cyl bike, I install the pistons first into the cyliders, then drop the cylinders onto the cyl block and put in the piston bolts,, I find it easier this way, I just put a block of wood under the cylinders and pack some rags into the block in case I drop one of the retainer..

Chet, Some good advice so far... I suggest you go to NAPA and get some spray gasket sealer. It comes in a blue can. It comes out like red spray paint...

You spray it on mating surfaces and both sides of the gasket. It tacks up quickly but doesn't dry. Put the gasket down on your block and then as your noted, have 2/3 at TDC. Set the block on those two and work the block over as you pinch the rings. The trick is to then swing the crank around so that 1/4 come up and you can get their crowns started before letting the block down too far and they are still flopped to the sides. That is the point of the wooden things... they are just a third hand to keep those two rods upright and not flopped becuase as soon as the block gets all the way over 2/3 rings/pistons, it wants to slide down.

It isn't rocket science and just take your time and don't force the block over the rings and crack one of them. Use some ATF or Marvel Mystery oil on the piston skirts for lube. Either will quickly burn off at about the same time the engine starts self lubricating and allows the rings to seat quickly.

personally ive allways installed the pistons/rings dry that first couple passes up and down the cylnder is the make or break for seating rings.i allways clean the bores with carb cleaner and wadded up toilet paper it will show any trash thats in the cylinders and will not leave lint in the cylinders like rags do!(really works!)do not break in a new set of rings with synthetic oil they will not seat properly,put a couple hundred miles on motor,change oil then wait 2000-3000 miles before using synthetic oil!goodluck,happy wrenching!

Sorry, I can't help Chet with an answer, and I really don't mean to hijack your thread.

If rings are replaced do you hone the cylinders first? And why would just rings need replacing, and not a whole bore job and pistons?

Thanks

I use sheetmetal and big hose clamps as ring compression tools. Next time might try putting pistons in block first and attach wrist pins last.

It is possible to be in a position where you only need rings. A race motor that needs to be real tight. As long as valve seats, guides and seals are in good shape. Doesn't take much actual wear to get to the point where you need a first overbore. Cylinder finish is critical to bedding in new rings.

OKC_Kent wrote:

Sorry, I can't help Chet with an answer, and I really don't mean to hijack your thread.

If rings are replaced do you hone the cylinders first? And why would just rings need replacing, and not a whole bore job and pistons?

Thanks

Seized rings. The cylinder is clean and within spec, so boring isn't required. As I understand it, honing is required any time you change rings, because the small amount of surface abrasion helps to break in the new rings.

11,800 original miles on the clock, and the rings all came off the pistons without breaking. The only problem was that the rings were stuck in the grooves and not moving freely, and I can't imagine that it's wise to reuse rings once they've come off of the piston.

I'd tried the Marvel mystery oil trick (leave it in the cylinder overnight, then ride around until it stops smoking) but it didn't help. The rings were quite stuck, and on the cylinder with the lowest compression (105 PSI) the rings were frozen in place with the gaps aligned!

Kent, The key to a rebuild is to measure the piston to bore clearance. If it is within service spec (smaller clearance), then all that needs done to freshen worn rings is to replace them along with honing the cylinder walls. This is done to roughen the bore surface which develops a glaze over time. Once the new pistons move in the bores, the rings seat in providing better compression. Of course, this should be accompanied by freshening your cylinder head and the valve train and the cam chain and its associated bits.

Both the pistons and cylinder bores wear over time and the clearance increases. Once it exceeds the service spec, the answer is to BORE the cylinders and replace the pistons with larger that will satisfy the service clearance requirement. Almost all Kaw applications have (or had) at least one oversize piston available. By going oversize, you are not increasing displacment noticeably (a couple CCs). You can also buy an oversize piston kit from a company like Wiseco and bump displacement at the same time as meeting the service spec for clearance.

Always run AWAY from any machine shop that is willing to bore your cylinders oversized without having the pistons on hand.

Post edited by: wiredgeorge, at: 2005/12/30 16:08

gulag wrote:

Hi,, now my english is not 100%, so Im not sure what you mean by "jugs"?

when I install cylinders on a 4cyl bike, I install the pistons first into the cyliders, then drop the cylinders onto the cyl block and put in the piston bolts,, I find it easier this way, I just put a block of wood under the cylinders and pack some rags into the block in case I drop one of the retainer..

Good advice about using a rag to keep the circlips from causing headaches!

I'd thought of installing the pistons first, then installing the wrist pins later. The idea of putting side stress on things worries me, though -- I've got one piston with a wrist pin that does require some force to get into place, and I'd hate to cause damage while tapping the wrist pin into place.

Is it safe to put lateral stress on the piston while installing the wristpin? Has anyone else tried this?


Everyone's set my mind at ease a good bit about getting the cylinders back on by hand. I tend to worry about jobs first, then afterwards I'm always pleasantly surprised when things go better than expected.

Now I just need to wait for the local shop to get my rings in...

:pinch:

Chet, I'm thinking about your method... Why don't I put the pistons in the barrels/ bores first, then the wrist-pin. There must be a reason why I didn't try this? It might have something to do with the risk of dropping circlips.

Gulag, raises an interesting question on "jargon".
Should barrel be singular? There is only one casting?
Pots = cylinders barrel and sleeves?
Jugs = sleeves, liners, barrel inserts and barrels?
Jugs = Piston and sleeve assy?
Boring a barrel is not the same as boring a sleeve?

Sometimes when building a 4 pot 1300cc machine, we have to bore the block to take the bottom of the sleeves, bore the barrels to take the sleeves and then bore the sleeves to take the pistons... Did I leave out jugs! Happy New year! Hope it's not too boring!

Regardz

Post edited by: Garn, at: 2006/01/02 15:57