Head gasket GS1000G questions

[Matchless]

If things are carboned up on piston and valves it could be from incomplete combustion. Should not be oil as you have newish rings and supposedly new valve stem seals at the same time. Might need to do the coil relay mod. LOL.

The carbon does worry me a bit unless the PO did very slow town riding and never burned it properly. I am suspicious of the valve stem seal though as I found that it would give out some blue smoke on starting if it had been standing for a few days.
I hope to pull the valves this evening to see what they look like.

The relay mod has not been done yet!!! The relay is mounted and the fuse box replaced, but I have procrastinated!

[Suzuki_Don]

Check your voltage at the coil first.

[psyguy]

sounds like you should be able to get away with just new piston rings (no re-bore, etc)

piston circlips need replacing with new even if they look good - chances are they dont have the required elasticity
yea, they fly, too

you may want to measure the diameter of the piston pins, they should not come out THAT easily, need to be a snug fit

[psyguy]

"no special tools needed"

You then put a spark plug socket spanner on the valve keeper and give it a mighty thump with said 2lb or was it 3lb hammer. The valve spring keeper, springs and any other bits compress but the valve doesn't because rag or half tennis ball stops valve from compressing.
Don

aussie ingenuity :-D

[Matchless]

sounds like you should be able to get away with just new piston rings (no re-bore, etc)

piston circlips need replacing with new even if they look good - chances are they dont have the required elasticity
yea, they fly, too

you may want to measure the diameter of the piston pins, they should not come out THAT easily, need to be a snug fit

I have cleaned up quite a bit last night and will do some more detailled measurements today.

The valves are out, intakes have nice shiny even faces. Exhaust faces are even, smooth but sort of blue/black not shiny. Does this indicate something?

[TheCafeKid]

I have cleaned up quite a bit last night and will do some more detailled measurements today.

The valves are out, intakes have nice shiny even faces. Exhaust faces are even, smooth but sort of blue/black not shiny. Does this indicate something?

I think that the intake and exhaust valves were made of different grades of metal. The exhaust would likely be more inclined to be made out of a higher heat resistant type of steel and I recall them being a black/blue colour, so you are likely ok.

[psyguy]

The valves are out, intakes have nice shiny even faces. Exhaust faces are even, smooth but sort of blue/black not shiny. Does this indicate something?

different material?

dunno really 8-[

[Matchless]

Thanks that is good news and as the faces are smooth it does not indicate any problems. As per the lapping debate and the instructions in the manuals would you chaps suggest a very light lapping. I still have to do a quick leak test with some fuel in the head and do not expect any problems there. Psyguy, I have just sent a mail off the Z1 to see if they can supply a set of rings and the rectangular gasket, plus the circlips

[psyguy]

valve lapping debate

i lapped mine with semi-fine paste just enough to remove any carbon deposits and shine the seating surfaces
next time though i think i'd have the valve seats re-cut by a machine shop, gives you the best possible seal

re parts, good luck with z1
consider replacing the valve stem guides if it hasnt been done yet, and valve stem seals are a must (they are inexpensive, but i know, it all adds up...)

[AirCooledHeaven]

I plan on pulling the heads and cylinders on my GS1000G 1980 and have a full gasket set from Parts'n more. Its made by Athena and seems fairly complete with many o-rings included.
The head gasket has me a bit stumped, it seems to be made of two layers of solid metal and in some threads the issue of extra seals on the outer studs were discussed but I do not see any in the set. There are also 4 copper crush washers which I do not know where to fit.
Any suggestions on which is up or down and the outer studs sealing?

PS: I also cannot find a rectangular o-ring that fits around the camchain opening in the set.

Thanks

Hi I have 2 after market gasket sets for the GS1000G, one made by Athena and one made by NP. Both of them contain the cam chain tunnel 'O-ring' that you are missing. My Athena gasket set came with a parts list inside (in Italian), and clearly shows part number 09280-99003, this is the suzuki part number for the rectangular o-ring. The copper crush washers fit on the outside 4 corners of the head gasket to seal the oil ways, flat side on the barrels. It appears Athena prefer these copper crush washers to the rubber seals that came in my NP gasket set. I haven't yet decided which to use. My Athena set also included 4 new flat copper washers to go underneath the chrome cylinder head dome nuts, 4 new copper washers for the inlet stub vacuum take offs, and an oil filter cover o-ring. So pretty comprehensive in my opinion. It sounds like your Athena set is missing parts so i'd get back on to your supplier. If you don't have a copy of the parts list then PM me and I'll send you a pdf.

Cheers

[psyguy]

great news

heh, ACH, great to have everything we had discussed about that gasket set confirmed by somebody who actually has the exact same set!

[Matchless]

Very true that was again a very helpfull post. I have PM'd him for a the list.

I have just come back from our engine parts rebuild supplier and he has confirmed that piston rings for a Fiat Palio is nearly the same as the GS1000. He has stock of Hastings rings at R200.00 for a set of 4 inclusive of VAT, that is about $25.00 USA. The standard size is apparently nearly the same as my GS second largest oversize. He has no stock of the .60 oversize on the standard (Fiat) bore diameter of 70.8mm and will have by the end of the week. The endgap is a bit large with the ring in the bore at .80mm with the standard rings.

Any advice on the valve guides will be welcome. They look good, not oval to the eye. A 7mm drill bit fits loosely into the guides and a 7.2mm does not go in at all. The valve stem seals were hard and worn slightly oval, unfortunately I pinched them closed when removing and could not examine properly closeup. I have those and will definitely replace.

A Ampro honer cost R195.00 ($25 USA)

So far no-one here sells the C-clips separately.

I have also bought a meter of o-ring rubber 3mm diameter and will try to make up the cam chain gasket. The old one came out broken, but sealed in with a black silicon gasket sealer and seemed to hold up. I think on the previous engine rebuild they reused the old one that was already damaged.

[psyguy]

piston rings end gaps are very important so i wouldnt play with those unless you can get them exactly to factory specs - after all the reason for taking things apart was that low compression and end gaps play a big part of getting the best compression

you do want to lightly hone the bores, it helps a lot with the rings setting in properly

as for the valve guides you need to have the valves in (with no springs), have them in their open position and move them from side to side to see if there is any play in them - if there is any play valve stems are probably worn a little but the guides would be worn a little too - so replacing just the guides is a cost-friendly option as the valves are rather expensive
if you get no side play with the valve stems, well that'd be great news

[Matchless]

Hi,
My gasket set issue is becoming quite interesting and I thought I should post what I have to date as this may affect others as well. Any comments will be appreciated, especially any other users of the same gasket set.

Just to summarise:
I have an Athena, complete gasket set, dated 2006, for the GS1000 80-81, bought from Parts'nmore for $61. It has no rectangular o-ring gasket for the cam chain opening part number 09280-99003 included. The rectangular cut out in the head gasket is only as small as the cam chain opening and overlaps the o-ring channel completely right up to the edge of the opening channel. Mark has sent me a picture of his NP headgasket and his Athena (1995) that both have the o-ring included in the sets, but the cam cutout on both his does not cover the o-ring channel. On his two gaskets the rectangular 0-ring around the cam chain thus seals head to cylinder. If I had to use an o-ring on mine it would seal cylinder to gasket - obviously not correct.
Mark also has rubber seals in the outer 4 studholes on both his head gaskets and mine has nothing with the holes being much smaller.

Basically my deductions so far is that it seems as if the rectangular cam chain o-ring gasket was purposely not provided in my set and that the headgasket is supposed to seal right over that channel and the same goes for the outer studs. Can this be right?

Now I must also mention that the head gasket is made of 3 loose layers of metal with some sort of black graphite like covering on the outside. Maybe this gives a better seal than the 30 year old technology used on the older gaskets?

I have also found that Suzuki has superceded the part numbers for the head gasket 5 times already:
11141-49002
11141-49003
11141-49004
11141-49004-H17
11141-49410
Could this mean that they have improved (thus changed) something on the OEM head gasket since then? Unfortunately we still have the same workshop manuals that refer to the first type of gasket installation only.

I have also discovered that my motor was overhauled in 1994, a date is inscribed on the top fin. The old 1994 head gasket that came off is a 3 layer, but had a slight silver covering on the outer. It also has no seals on the outer 4 stud holes and the gasket also covers the cam chain opening o-ring channel completely. None of the holes, stud, screw, piston, cam chain have any folded over metal on the edges, just the bare 3 layers loose on top of each other. The mechanic who did the overhaul must also have had a similar dilemma and fitted the old and very mangled o-ring under the gasket with silicon rubber. I can now guess that he also did not get a o-ring in the set and reused the old one, but put it in the channel with the gasket over it and that must have mangled it more. There were no oil leaks visible on my bike to date!

Now comes the million dollar question. Can I fit this type of head gasket without any seals on the outer studs and without the rectangular o-ring seal around the cam chain opening?

[AirCooledHeaven]

Hi,
My gasket set issue is becoming quite interesting and I thought I should post what I have to date as this may affect others as well. Any comments will be appreciated, especially any other users of the same gasket set.

Just to summarise:

snip...

I have also discovered that my motor was overhauled in 1994, a date is inscribed on the top fin. The old 1994 head gasket that came off is a 3 layer, but had a slight silver covering on the outer. It also has no seals on the outer 4 stud holes and the gasket also covers the cam chain opening o-ring channel completely. None of the holes, stud, screw, piston, cam chain have any folded over metal on the edges, just the bare 3 layers loose on top of each other. The mechanic who did the overhaul must also have had a similar dilemma and fitted the old and very mangled o-ring under the gasket with silicon rubber. I can now guess that he also did not get a o-ring in the set and reused the old one, but put it in the channel with the gasket over it and that must have mangled it more. There were no oil leaks visible on my bike to date!

Now comes the million dollar question. Can I fit this type of head gasket without any seals on the outer studs and without the rectangular o-ring seal around the cam chain opening?

Andre, I think you probably just answered your own question, your bike has been running fine with no oil leaks since 1994 using exactly the same gasket arrangement you have now, so maybe its OK to go with it?