Talk me into replacing the base gasket....

[Andrew Vanis]

Talk me into replacing the base gasket....

Did the valves on the 81 gs750L. Don't want to deal with reinserting pistons and all the can of worms that could entail.

Head never got as clean as I like. Cylinder section still has staining and even if I get that clean, then the main block has staining. I just want this done and I don't want to deal with having to reinsert the pistons and then wondering if I shoudl have honed the cylinders and replaced the rings. Cycle has about 18K with me putting on about 15k of that mostly 10 years ago.

So talk me into or out of it.

[posplayr]

Unless you want a parts bike, you don't have a choice.

[greg78gs750]

its not that bad, just don't make it worse for yourself by getting accumulated crud into your crankcase. Hardest part is scraping the old gasket off.

[Andrew Vanis]

Unless you want a parts bike, you don't have a choice.

why/how would not replacing the base gasket make it a parts bike?

[Nessism]

Do the job right the first time, and that includes OEM gaskets and seals, including the valve stem seals. Short cuts become long cuts when working on a 35 year old vehicle.

[hillsy]

why/how would not replacing the base gasket make it a parts bike?

That's probably a bit of an exaggeration, but any time you undo the head you disturb the base gasket and it will leak / need replacing.

[posplayr]

That's probably a bit of an exaggeration, but any time you undo the head you disturb the base gasket and it will leak / need replacing.

Say you see a used a bike that would not run but was clean as a whistle. It is still a non-runner and nowadays that is a parts bike.

Now say you see a used bike that runs, motor is real clean, but is leaking like a sieve. How much is that worth? Attribute appropriate value to a PO that pulled the head without getting it to stop leaking.

I would rather have a bike with carb or charging issues than one where i had to pull the barrels and head.

[Brendan W]

It's highly unlikely that your are anywhere near new rings and or honing at that mileage. It's equally likely that the original base gasket and oil gallery o-ring seals are hard and have a high probability of leaking now.
Getting the pistons back in is no big deal. There are at least four different ways that people swear is the best way to do it. If I can do it anyone can. In the context of the entire job base gaskets are dirt cheap, you get a chance to inspect the piston skirts and do a bit of light de-gumming of the rings. It's a no brainer for me.

OTOH you'll be fine, just button it all back up and check out my online store. Bulk discount on engine degreaser and oil. Half price headgaskets ( QC rejects but what the hell, guys not replacing the base so he'll be back for another )

[Andrew Vanis]

Cylinder off....I'm committed

OK, Mr. "Its a no brainer for me" hints on the following?

Getting the pistons back in is no big deal. There are at least four different ways that people swear is the best way to do it.

....

you get a chance to inspect the piston skirts and do a bit of light de-gumming of the rings. It's a no brainer for me.

[Brendan W]

Cylinder off....I'm committed

OK, Mr. "Its a no brainer for me" hints on the following?

First, when you are taking the thing off make sure it comes up true and that you have control. You don't want it dropping back half cocked and breaking a ring.
Removing the old gasket will take time. Be patient and gentle, using repeated applications of solvent and no gouging. Plug the holes in the crankcase with paper towels or similar to stop chunks falling in.
Don't get heroic and remove the rings. Gentle wipe with solvent all they need, if even that.
Going back there are surely dozens of threads here with pictures. They fall into four main categories.
Full on Suzuki ring clamp kit - hardly anyone does it.
Fingers, fingers, fingers - some can, I can't.
Popsicle sticks - as for above, I don't get this one.
Plastic strips from a bucket with hose clamps - works for me. Middle two cylinders first at tdc, then crank over a bit and get the outers started.

Some folks use wooden blocks to support the barrel. I support it from the frame.

[Andrew Vanis]

"Don't get heroic and remove the rings"

rings - so remove or don;t remove the rings?

thanks for the help on the other stuff.

also don't fully understand the last line "I support it from the frame."

[850 Combat]

My GS1000G in Oregon had the head gasket changed about 9 years ago without doing the base gasket. It doesn't leak. Even though I have personal experience that what everyone is saying isn't necessarily so, I still agree with them. I didn't have time, and I paid someone to do it. When it was over, I found out that he didn't complete the job the way that I asked him to. I've been running it ever since without any base gasket leaks. So far

[Brendan W]

"Don't get heroic and remove the rings"

rings - so remove or don;t remove the rings?

thanks for the help on the other stuff.

also don't fully understand the last line "I support it from the frame."

Unless the rings are broken or clearly damaged, which they won't be, leave them alone.
I tie the cylinders to the spine of the bike with a ratchet strap.

[Andrew Vanis]

FWIW, Oven cleaner makes a BAD cylinder cleaner. Reading the product label would have helped.