1978~80 GS1000 head gasket differences.

[rustybronco]

Sedelen (Steve) and I have been trying to figure out which different types of fastening 'methods' were used on the 1978-79-80 GS1000's and when they started using each method of bolting the cylinder heads to the cylinders.

Pat numbers as listed in the catalogue for the different years.

[code]1978 GS1000 cylinder P/N 11210-49000 no boss or bolt hole

1979 GS1000 cylinder P/N 11210-49001 has boss 'possible' bolt hole

1980 GS1000 cylinder P/N 11210-49002 has boss and bolt hole

*******
1978 GS1000 head P/N 11100-49810 no boss

1979 GS1000 head P/N 11100-49820 has boss 'possible' bolt hole

1980 GS1000 head P/N 11100-49830 has boss and bolt hole[/code]

My 78 came without the extra boss located at the lower front center of the engine.
The boss, if it had one, would be located on the head at the center top of this picture... http://i32.photobucket.com/albums/d4...o/IMG_2671.jpg

Steve's 79 GS1000 has the boss but the hole isn't threaded. His is an early built 79 model if that matters.
It's similar to this one but without the extra threaded hole... http://www.ebay.com/itm/360316263189...84.m1438.l2649

Finally the 80 cylinders which do have the extra boss and bolt hole.

Okay, on to my question for you 1979 GS1000 owners. Would you mind looking at your bike to see if it does or does not have a threaded bolt hole and get the production date on it as well.

Thank you for taking the time to look.

[hampshirehog]

Both my 79 SNs have the threaded hole. One is an early bike (actually 78 reg year) the other is September 79.

[althomas101]

I'm a GS noob so go easy on me. What exactly are you talking about. I recently got a GS1000L that has low compression so I need to do a top end rebuild since it isn't the valves. I was considering getting a second set of heads/pistons off ebay so that I could do the machining without having to take the bike apart for a somewhat long time. If the cylinders/heads are not interchangeable then I need to know what to look for. Some clarification would be helpful, thanks.

[rustybronco]

You can see the difference I'm speaking of in these two pictures.

With the extra boss (top center)

http://i32.photobucket.com/albums/d44/rustybronco/PICT3445.jpg

without the boss...

http://www.ebay.com/itm/Suzuki-OEM-NOS-Gasket-Cylinder-GS850-GS-1000-GS1100-78-84-72ID-/221045717404?pt=Motorcycles_Parts_Accessories&hash=item337759f99c&vxp=mtr

And welcome to the GSR!

[althomas101]

AHH, thanks. I wasn't seeing that from the previous pics of a head and cylinders.

[rustybronco]

If yours has the extra boss, which it should, just find a cylinder with a hole that's threaded. you can use it in place of the one that isn't threaded.

[althomas101]

If it helps any I checked my bike today and it has the boss and a bolt. It is dated April 1979.

[sedelen]

I took a few pics of my head to cylinder mating areas today, sorry about the quality, but there is no bolt, or hole for one. I do believe it's built up for that, you can see and decide for yourself.

[sedelen]

I'd like to see some pictures of the cylinder to head mating area of a GS1000 with the bolt so I can better make out what's up with mine.
I'm not the original owner, who knows it could be a mis-match of parts, but until I see other pic's I can only guess. At this point I only think it was built this way, bike had 24K on it when I got it, and who knows how many prior owners it has had. For my 1100 I do know I'm the fifth owner.

[Griffin]

Here are some pics of that area from my (kinda grimy) '80 1000G (manufacture date April 1980). I think the head/cylinder tang would be the same on an '80 1000E. As you can see, the bolt actually comes up from the bottom.

[sedelen]

Here are some pics of that area from my (kinda grimy) '80 1000G (manufacture date April 1980). I think the head/cylinder tang would be the same on an '80 1000E. As you can see, the bolt actually comes up from the bottom.

OK, that clears up a little, I think? In your second picture I see threads in that built up area on the head, mine is solid. Also, your cylinder has a built up area that looks to be ground off on mine.
I tried to get better pic's, seems anything close by the camera will focus on and throw the area I want out of focus.

Here's the cylinder head looking down, see.......... solid, no threads.


The gasket extends completely and only to the front of the cylinder, not out underneath the head. I would think if the gasket was made for the screw, there would be a section there missing from the gasket the width of the screw, or part of the width of a screw, as I think the screw would go somewhere through the face of that ground off area.


And now a "bottom" shot, no hole. This leads me to believe they were in the process of producing the newer bolt hole head and cylinders but probably weren't ready yet. So, I believe this is a stop gap '79 model (Aug 78 build date) because if it were a later one, there would be threads in the head, and the cylinder block wouldn't look ground off as it does and would have threads showing. I believe the '78 cylinder is more rounded where mine looks ground off..

[althomas101]

Mine looks exactly like Griffin's.

[althomas101]

Griffin's pictures are gone, to keep this relavent I'm replacing them. I highlighted the bolt yellow it installs from the bottom.

https://goo.gl/photos/toNUQg9S89FZDGEv7

[uk gs nut]

I have a 79 GS1000N not sure of build date, but it has neither boss on head or block. I have a cometic gasket and it has provision for the bolt and it sticks out front of engine. I cut it off flush to look neatest

[althomas101]

The picture I took was from my 1979 GS1000LN.