Cylinder Head is off, Now What?

[RyanBiggs]

My '79 GS1000 was starting to seep oil from the head gasket, and I had the pipes and carbs off for other work. So I figured I'd take off the head and replace the gasket. Sure enough, it looks bad where it was leaking. But I'm not sure what I got myself into!

The question is, now what? I pretty much have a handle on the most I should do (complete top end overhaul). What do you think is the least I should do? Compression was 149/139/145/151 psi last I checked, which I'm under the impression is OK, so I feel like there's no need to turn a big project into a giant one...

It seems to me that to do the job right, I should at least replace the cylinder block base gasket, but then that means replacing the rings and the hassle of getting the block back over the pistons. And my Haynes manual says if I do that, I should have the bores "glaze busted". Sounds like potential headaches.

Also, should I do something about cam chain tensioning bits? I have the classic chitty-chitty-bang-bang slapping...

Suggestions/Experiences?

 

[posplayr]

My suggestion

My suggestion

Since you are asking, it will take you 1/4 the time if you get someone familiar with this to help do it or do it for you.

Speaking from experience.

I bent an oil ring the first time(with engine out, on a bench and being very careful and I have worked on motors a lot in H.S.

End result scrubbed a cylinder and had to go back in.

Pos

 

[RyanBiggs]

Haha wish I knew one! I might have bitten off more than I meant to, but that's where I am now. The question is which is riskier: just slapping back on the head with a new gasket and crossing my fingers that the base gasket seal will stay OK, or pulling off the cylinder block and dealing with all that?

 

[hampshirehog]

As your numbers are good there's probably no need to change the rings. Do the measurements (free end gap and gap halfway down the bore) and if ok re-use them.

If you reuse the same rings in the same cylinders there's no need to hone.

Popping the cylinders back on is tricky - I always do it at a very slight angle so that, for example, top ring on no 1 goes in then top ring in no 4, then 2nd ring in no 1 and so on. Take it steady, chcke and double check, don't force things, use plenty of oil and you'll be fine.

Have a look at your cam chain tensioners and make sure they're not excessively worm / bent etc plus measure the chain across 20 links as per the manual. If it's all in spec rebuild your tensioner (I'd strip it anyway - it's dead easy).

Might be worth lapping in the valves for peace of mind as you've got the head off.

 

[posplayr]

Two more bits of advice

Two more bits of advice

Haha wish I knew one! I might have bitten off more than I meant to, but that's where I am now.

Commitment to a task; I like that.

If I had it to do again (given my recent experience and having do it 3 times):

Two things that helped on the ED when we recently did this is to use a 3 or 4" hose clamp (Hardware store ; u need 2). They are the perfect size to cover the rings. Make sure the adjustment screw is not sticking out to damage the rings.

Bill(Chef) and I clamped them on snuggly so that the tapping on the cylinder would push them down on the piston. When they are too loose, the first push and they pop off.

If you have a Friend to help (even inexperienced it will help).

Next when dropping the cylinder do not rock (left to right) it as rings that were in can pop out again. Straight down once the rings are in.

Next is you have to do this two cylinders at a time. Bill likes to drop the timing chain down into the front of the engine to lock the crank while 2 and 3 are up. This was a little tricky and you have to drop in the chain and make sure the crank will not rotate. If you do when you push down on the two cylinders it just goes down and the other come up and you are trying to put all 4 on at once.

Apparently you can also use a piece of wood under the pistons; Sounds easy.

I know it is possible to do without clamps, Guys like RapidRay use fingers and the flatside of flat screw drivers to push in the rings. He can drop a cylinder down in 15 minutes single handily.

OEM rings doesn't seem to be as stiff as Wesico.

Depending upon your money situation I might also be tempted to do a position kit as it gives you a fresh engine. Other than the kit, use need honing and maybe a decking of the head to clean the surface (lap in the valves of course). It will certainly last longer (if you put it back together right)

I would suggest not using the MLS gasket if it comes in the Weisco kit :evil:.

Popping the cylinders back on is tricky - I always do it at a very slight angle so that, for example, top ring on no 1 goes in then top ring in no 4, then 2nd ring in no 1 and so on. Take it steady, chcke and double check, don't force things, use plenty of oil and you'll be fine.

I will defer to Hampsirehog on this, but we have had rings pop back out of you rock down. I thing his advice applies to first getting the rings in the bore. With the hose clamps this would not apply.

I think Rapdiray will tell you once to break the head seal the base gasket has to be changed. If it is old more than likely. After running for a few minutes and spewing oil through the MLS gasket (again not recommended) we went to composite and same base gasket and all was good.

If the bike is old and the jugs never off, U probably need to change the base gasket and the cylinders need off .


Pos

 

[Hank.SD]

My 1100E is apart for the same reason, head gasket leaking like sieve in the center. I checked for bad orings on the center stud nuts but that was not the source of the leak.

I decided, since the bike is new to me and I'm highly suspicious of the PO's maint. schedule, to pull the block and re-ring. I bore mic'd the cylinders and they were well under the service limit and not out of round by much more that .001 so I just honed and ordered rings. I pulled a valve and they looked about perfect so I'm not doing anymore w/ the valves.

I checked the head and cylinder for warp and both were flat within .002. The service limit is .008 so I left well enough alone there too.

I would think once you're that far into it would be wise to re-ring, but I'm not an expert either. My engine has 20,400 miles on it.

I'll be having my friend/cousin who is head mech. at the local Suzuki shop come by to help me get the block back down.

 

[RyanBiggs]

Thanks for the advice. That's going to help a lot. Haha looks like in for a penny, in for a pound on this one!

 

[Steve]

I don't think there is any need to hone the cylinders if you have compression numbers like that.

Fitting the cylinder back down over the pistons is not much problem, either. It helps if you have an extra pair of hands to help, but it can be done without tools, usually.

"Classic chitty-chitty-bang-bang slapping"? Not sure how "classic" that is, you should not have any. While you have the tensioner off, you can clean it out to make sure it's working freely, then just make sure it goes on and is set correctly. I have seen some tensioners that were locked into place when they were installed, so there was no chance that they were going to be able to take up any slack that might occur.

.

 

[RyanBiggs]

I'll definitely be recruiting that extra set of hands when it's time to put the block back on...!

I was under the impression that cam chain slap was a common occurance in GS engines (at least GS1000s) at idle, and mine sure has it. At least, I thought that's what the remaining idle clatter was once I fixed the worn out clutch basket (which was even more noisy)! The tensioner doesn't look like it has any obvious problems, but I haven't really looked at it seriously or stripped it yet...

 

[Dogma]

What's the mileage (or kilometerage as the case may be)? Cam end slap is in high-mileage engines.

 

[Mobetter]

I'll definitely be recruiting that extra set of hands when it's time to put the block back on...!

+10 on that! I was able to do it by myself only after I had bent a ring and had to buy
another set for that cylinder... I hate asking for help... but I should have.
I did get it on by myself after a second try but save yourself some headaches
and get another pair of hands to assist.

 

[posplayr]

+10 on that! I was able to do it by myself only after I had bent a ring and had to buy
another set for that cylinder...

How the HeJJ did that happen?

http://www.thegsresources.com/_forum/showpost.php?p=836974&postcount=46

whoops here to

Pos

 

[atchbo]

I have a twin so it's easier, but you can just about squeeze the rings with your hands enough to get the jugs on... I used hose clamps as ring compressors and didn't replace my rings, just left the old ones on and checked that the gaps were facing different directions. I haven't finished putting the head back together (need shims) but the top end work seemed pretty easy to me. I didn't mess with the valve seals etc.

Think of it as a 'project' not a task, and just take your time and read the manuals/forums.

 

[Big T]

With your compression numbers, I'd just give the bores a quick hone and drop the barrels back on.

I would do the base gasket while I had the head off, and while you've got the barrel off, check the front and rear cam chain guides.

Just where is the oil leak? That's what I'd be concerned about. Around the cam chain tunnel? Between the cylinder and the outside?

I'd be concerned with the head and barrels being flat.

When I redid my GS1000, they messed up the boring and it was pumping oil into #1. I took it apart several times before a 2 stroke guy found the gouge. So you don't need to be putting in new rings just because you pull the barrel.

So, replace the soft things (gaskets, seals, maybe cam chain guides), hone it and reassemble. I got my rings in with hose clamps and a bit of motor oil. Pretty easy, just take you time

Happy motoring!

 

[Nessism]

With your compression numbers, I'd just give the bores a quick hone and drop the barrels back on.

I don?t think it?s advisable to hone the cylinder when reusing the same rings.

 

[Don-lo]

I agree with nessism: the rings are matched to the cylinders now. You have good compression. Slap it back together and go. If the base gasket starts to leak later, you can have the rings ready when you go back in. You can also do a total head cleanup then. You understand the top-end removal process, so doing it again will be much easier.

 

[Hank.SD]

After much deliberation I decided to replace my valve seals as well. Another $50, but I started to think about that 27 year old rubber and figured it was wise.

 

[blokv1100]

Interesting thread.

I am in the middle of this project at this very moment.

This is my first time doing this.

I broke her down Easter weekend (see attached photo)

I picked up the new gaskets yesterday.
I was able to get the cylinder jug down over the pistons last night. Wow, that was fun (NOT). 4 arms recomended, I only had two at the time.

Taking my time, when I get pi*sed, I stop and then try it again the next day.

I'll keep you posted on the progress.

 

[RyanBiggs]

Awesome, this is gold, thanks for your collected knowledge.

To answer a couple of questions, the engine has just over 30,000 miles on it, so the problem is primarily age as opposed to wear. I believe the oil leak was from the o-ring part of the gasket around the front right corner stud, around which appeared to me to be an oil passage. But maybe I'm crazy about that. It doesn't appear any oil has been getting into any cylinders.

I had just about decided that at least I knew I'd be pulling the cylinder block off, although Don-lo's argument sure is tempting. Knowing my luck I bet it'd leak though, which gives me pause. I've noticed after tapping the head off the positioning dowels, that oil appears to have escaped from around that base gasket...

If I take the cylinders off and manage not to tear anything up, I'm tempted based on this discussion to keep the old rings.

From an article in the August 2000 issue of Motorcyclist about the GS1000S: "When idling below 1000 rpm, most two-valve GS engines emit a metallic slapping or knocking sound. This is caused by the cam-chain design; at low revs, the chain slaps a bit. It's completely harmless, and has a simple cure: ignore it." I swear I had heard about this previously as well. Am I really the only one here with this quirk?

 

[Big T]

Since it's supposed to idle at 1,200 rpm, I wouldn't worry about it