Is there a guide to changing the head gasket?

[Guest]

During this winter I want to try adjust the valves on my 8-valve gs750 from 79. I will follow Bikecliffs excellent picture guide, so I'm pretty confident it will work out fine.
While I'm at it, I also want to change the head gasket, as this is leaking pretty badly.

Is there a "how to" on this topic I haven't found yet? I hope this can be done with the motor still in the frame.

[Dogma]

The service manuals explain this, and give inspection specifications for everything. I'm not aware of a GS-specific guide other than those. I wouldn't be surprised to learn that there is something on BassCliff's site.

There are some things to know that are not contained in the service manuals:

It is very likely that you will disturb the base gasket when removing the head. You will then need to remove the base gasket also. Go ahead and plan for this.

Change the valve guide seals while you have the head off. They're old. Inspect everything while you have it apart.

There are severe problems with gasket manufacturers other than Suzuki OEM. In particular, the base gasket and o-rings. Vesrah for sure is a guaranteed fail on the base gasket o-rings. I'm not sure about their head gasket, but their other gaskets are serviceable.

Others else will surely chime in with whatever I've missed.

Yes, you will be able to pull the head with the engine in the frame.

If you are new to working on engines, get ready to learn a lot. Please do not hesitate to ask any questions. We will make sure this is successful.

[tkent02]

Take your time, take a lot of pictures while you are doing it, write it up afterwards. Cliff will be happy to have a nice head Gasket Replacement Tutorial on his website.
And you will be the guy who "Wrote the Book" on this subject.

[spyug]

It really is not difficult, you just need to read over the appropriate section in your manual and follow along.

The big thing to remember is that a) what comes off goes back in and b) it goes back in the same place it came out of. This is especially true of cams and timing chain. There are specific marks on the cams and a spcified spacing for the chain links so familiarize yourself with those. It is also a good idea to mark the cam sprockets and the corresponding chain sections ( with paint or grease pencil) before dissasembly to aid when putting things back.

There are at least 3 different fasteners holding down the head so don't confuse those.

You will need a torque wrench and there is a specific pattern to torque down the head when reassembling so be aware.

Once the cams are back on but before finishing off make sure you adjust the valve timing, especially if you go to the work of cleaning up your head, valves and perhaps changing guides.

Take your time and don't rush and if you do have the time take pics and make a tutorial to help the next guy

Good luck
Spyug

[Walle]

I appreciate your input. I'm sure this will be a lot more extensive, than what I've thrown myself into before. I will read up on what tools and parts to gather before I open up Pandora's box.

[Suzuki_Don]

Walle as Spyug said, put bits back from whence they came, so if you remove the valves from the head make sure they go back in the same position. I usually get a piece 3x2 oregon and drill 8mm holes in it and put a valve and springs in each hole. I have another piece of oregon that I have cut holes in with a hole saw attachment for my drill to hold the buckets and shims and mark them on the wood so they all go back in their original positions.

Example below:



A little bit of extra time spend organising things beforehand makes the job much easier overall and much better than having valves, springs, collets, buckets, shims etc. all over the work bench and eventually getting mixed up and not knowing where they go when it comes to reassembly.

[Runningdog]

Oregan? I can see that it's wood, but Oregan?

[Suzuki_Don]

Sorry, I wrote the text before I found the pic. I knew someone would pick me up on that. Serves me right for being too lazy to go back and change the text.

Or I could Lie and say it's a special Australian variety of oregan only grown in the southern hemisphere.

[mlinder]

Are you sure it's Douglas fir, Don? Or is it Eastern White Pine?

[Suzuki_Don]

Are you sure it's Douglas fir, Don? Or is it Eastern White Pine?

It beats me Mark, all I know is that I have all these bits of wood lying around with different sized holes in them, now that my motor is back together. As for what type of wood they are, all I can say is I'm no forester, so my opinion is worthless.

[Dogma]

Huh. The pieces of wood I used to keep my parts straight looked exactly like zip-lock bags labeled with a Sharpie.

[BamaGS850G]

I have checked at Bike bandit etc. and don't see the head gasket listed for my GS850G. Also, as I've just learned from this thread, I should probably be searching for a base gasket and o-rings too. Since the OP will surely need to know also, could anyone tell me a good source for these?
Thanks in advance!
Adam

[Dogma]

I have checked at Bike bandit etc. and don't see the head gasket listed for my GS850G. Also, as I've just learned from this thread, I should probably be searching for a base gasket and o-rings too. Since the OP will surely need to know also, could anyone tell me a good source for these?
Thanks in advance!
Adam

When in doubt, get Z1 Enterprises on the phone and explain the situation. They only show what they have on their site, and they can get all the same OEM stuff as anyone else. Sometimes, a little more, since they will sometimes be able to wheedle something out of their Suzuki contact.

BTW, on the list of preferred vendors, BikeBandit is near the bottom. Not necessarily reprobate, but not really preferred. BassCliff's site has list of good vendors with comments in the README.

[DimitriT]

A few tips you may not find elsewhere:

* use a suction cup to remove the tappets (I use the suction cup on the end of a valve lapping tool)

* when reassembling use some sealer around the square o-ring in between cyl. 2 & 3 - this o-ring tends to pop out of position when its compressed and will result in oil seeping

* wipe some sealer on the base gasket around the stud holes which carry oil (both sides) - a very light coat of sealer - the base gasket compresses over time and will result in oil seep in that area

I used this stuff:

http://www.permatex.com/products/automotive/automotive_gasketing/gasket_makers/auto_permatex_ultra_black_maximum_oil_resistance_rtv_silicone_gasket_maker.htm

It's really important you get the head torqued correctly and that means not too tight.
I made the mistake of over-tightening the head and a section of base gasket squeezed
out of position and caused a leak.

BTW, my last head gasket on the 550 was done using a cheapo gasket kit off ebay - that was
2k miles ago and no issues so far although I threw out and replaced some
of the valve seals which didn't fit right on the guides.

[Walle]

Thanks again. All tips are welcome