piston rings,and barrel tips????

[grumpuszed1]

hi all,
you may have seen my previous post about running in newly built engine,thanks for the advice! however i was being a bit previous as i am now at the stage of actually rebuilding said lump, what i am asking is how exactly do the rings go on? ie which ring goes where and which way up etc, i may sound like a numpty but i would rather be shown the right way than fumble around and end up f***ing something up. also any tips on re-placing the barrels? i dont have access to a ring compressor and last time i did it 15 years ago it took me 4 hours!!!!! its all getting a bit urgent at the moment as my rd350 ypvs seized on me on wednesday night on route to paignton bike night devon (sympathy vote well and truly asked for) so the zed rebuild has moved up in the pecking order as you can imagine. any help greatly received and appreciated,cheers Graham.

[kiwiz]

I would ensure that you made up some wooden blocks to rest a pair of pistons on as the block is lowered. The specs are in most manuals but ensure its long enough to sit confortably across the crank case mouth supporting the pistons either side of the conrod.

My block was bored out to take a Wiseco kit and I had a devil of a job to get the barrels on. Even with the missus help and using Sykes Picavant ring compressors after 6 attempts and one torn base gasket I was getting pretty stressed. Bailed out and took it to the local Kawa dealer who had a couple of gray heads who knew about Zs. My problem was that rebore had removed most of the bore champfer making starting the rings into the bore quite hard. Even with the ring compressors I still found the oil ring rails popping out on one of the four at each attempt.

I really can see how you can do this job without compressors, and if rebored check the champfer is adequate. I did one of these 20 years ago without any trouble at all but that was just new rings and a hone

[Phil50]

Hi Graham

First get a really powerful magnifiying glass or jewellers eyepiece. Unless your eyes are like an owl's.

I have just put new rings on my Z900 A4. There should be a letter and a number stamped on the rings a mm to the left and right of the gap. the letter should be a letter T for top and 50 (may be another number) The T is for TOP and the T should be facing the TOP of the piston. Both first and second ring have the T on them. Now the first ring the TOP ring should be the one that is a block type with a slight chamfer on the top edge.

The second ring also must have the T facing the top of the piston and that should have slight cut out on the inner edge. That cut out bit must face down toward the bottom of the piston ( In case the T is not on your rings)

Now the oil ring on my set is in three parts. Two indentical thin rings no stamps and a crinkly ring like a large washer. These are fitted as on ring with the washer crinkly bit sandwiched beteen the thin rings.

My kit came from Zpower and is a clone of the original Z900 A4 and was from doreme-.com I think.


Hope this helps
Phil

[kiwiz]

My experience has been with the wiseco only.

I queried them on which of the two comprision rings was which as the kit didn't say. The bright shiny one was the upper and the dull one the lower compression. Check the ring gaps in the bore before fitting. I have nver found these needed doing but it pays to check. All that is required is a feeler gauge and use the piston to square the ring up in bore.

The oil rings were more of a problem particularily with the expander. It says the ends cannot over lap but its real difficult to see the gap with my poor eyesight. as an aid to finding the gap I pinned the expander ring in place with a piece of fine wire through one of the oil holes where the expander sits. I then worked around the expander ring with a tooth pick until if found the bit that moved. Thats where the gap was. Removing the wire I them moved the gap to the correct position on the piston . The rail gaps were in line with the piston pin but are easy to see even for the near blind.

[Pigford]

When I rebuilt my Z1A with a 1015 Wiseco, I replaced the barrels single handed with a fair bit of patience, oil and support of the barrels with wooden chocks. Took a long hour or so! As everyone rightly says, the oversize boring removes lots/most/all of the bore chamfer. This can easily be machine back in, but its obviously best to get done at same time as the re-bore
The "gapping" of the rings is crutial. Place the rings (top 2), one at a time in the top of the bore, about an inch or so down. use a feeler gauge to check gap If less than minimum gap figure quoted, remove ring & CAREFULLY dress with a small file. Best to hold file in a vice and gently rub ring back and forth, removing a bit at a time & recheck. Once gap is within limits, make 100% sure its put on the piston thats gonna go in that particular bore it was measured in! Best to mark all pistons with indelible marker before hand!

[grumpuszed1]

well what can i say guys, but thanks a bunch for the advice, i checked the ring gaps in the bores,these were fine and well within the 0.2/0.4mm tolerance stated in the manual, 2 ,1inch thick pieces of wood were placed under the two central pistons, carefully turned engine over by hand till pistons were locked on to wood, slid barrels down feeding rings into bores carefully (only bored out to 0.5mm o/s) this went scarily well! removed wood repeated with outside two pistons JOB DONE!!!! all took less than an hour! i could do this for fun you know (well ok not really) once again thanks for the help much appreciated just waiting for new cam chain tensioners from z power then i can get the head back on and get her back on the road for whats left of the summer, cheers all, graham.