Tracking down a knock on a '78 GS400. Need help getting the cylinder off.

[tatu]

Back in the day Suzuki made a special tool for lifting the blocks, I was trying to find an image on google. It consisted of two flat blades of aluminum that is pivoted at the handle end with a cam that levered the block off, it wedged into the place you have shown.

My memory is a bit off, but here it is.
Pretty hard to find in the 'net' but available still it seems on ebay
Photo from Alpha Sports.
Maybe a heel-toe prybar you will some purchase enough just to start the gasket, once its cracked it goes easy.
Good luck

cylinder removal tool.png
Also it isn't made of ally

[Gorminrider]

Be triple-sure you have all the bolts out. They are NOT "inaccessible". with the motor out of the frame. Refer to the shop manual and the parts diagrams for clues. There are often "levering points" mentioned in the manual for screw-driver tips, but applying massive force is always wrong. Hammering a broomstick around the edges will eventually shift it if ALL the bolts are out.

added: Forgetting a crucial step is not uncommon so stay with the broomstick while you think on it.

[ItsBork]

Be triple-sure you have all the bolts out. They are NOT "inaccessible". with the motor out of the frame. Refer to the shop manual and the parts diagrams for clues. There are often "levering points" mentioned in the manual for screw-driver tips, but applying massive force is always wrong. Hammering a broomstick around the edges will eventually shift it if ALL the bolts are out.

added: Forgetting a crucial step is not uncommon so stay with the broomstick while you think on it.

Unfortunately it seems (at least from the manual and my eyeballs) that the gs400 is the only engine that doesn't have levering points. The manual mentions them for the 450 but it says for the 400, once the head is off, it should take nothing more than some raps from a plastic hammer to lift the cylinder. I did find that one bolt inside the camchain tunnel but I don't see how you possibly get to it even with the engine out.
Is it possible there's something on the oil pan side holding it down? I suppose it wouldn't hurt to drop the pan anyway just to clean out 40 years of crud.

[Gorminrider]

Unfortunately it seems (at least from the manual and my eyeballs) that the gs400 is the only engine that doesn't have levering points. The manual mentions them for the 450 but it says for the 400, once the head is off, it should take nothing more than some raps from a plastic hammer to lift the cylinder. I did find that one bolt inside the camchain tunnel but I don't see how you possibly get to it even with the engine out.
Is it possible there's something on the oil pan side holding it down? I suppose it wouldn't hurt to drop the pan anyway just to clean out 40 years of crud.

Yes,sorry, I was muddled with the lower case...it's commonly got pry-points I remember now. Still, while I don't have that older 400/425 or a manual for it, I looked at your pictures and I don't see it or remember anything to do there except the tensioner blade that won't come out that way on my bike..AND I still think it'd be pretty odd to put a bolt in an inaccessible place without mentioning a "special tool"..The original shop manuals are pretty good at that. I don't remember any issues getting the cylinders off my gsx400 after the engine was out, and the head was removed, beyond hammering on my sorry ol' piece of broomsick in creative ways. I haven't yet had a use for a plastic hammer. The impact is too wide and clumsy and wooden mallets are waay better imo.

as to the sump, you never know! People find all kinds of goodies in there and it does no harm. Rock the engine around a bit and you may be -aah-rewarded?

But If you think it was in the clutch, I'm a little unsure why you're taking the pots off...? is there any chance the noise is those springs in the clutch-boss? ( I don't mean the actual clutch springs -the other ones) I have a bike that I think rattles those a bit. It doesn't affect the way I ride it so it'll wait.

[ItsBork]

Yes,sorry, I was muddled with the lower case...it's commonly got pry-points I remember now. Still, while I don't have that older 400/425 or a manual for it, I looked at your pictures and I don't see it or remember anything to do there except the tensioner blade that won't come out that way on my bike..AND I still think it'd be pretty odd to put a bolt in an inaccessible place without mentioning a "special tool"..The original shop manuals are pretty good at that. I don't remember any issues getting the cylinders off my gsx400 after the engine was out, and the head was removed, beyond hammering on my sorry ol' piece of broomsick in creative ways. I haven't yet had a use for a plastic hammer. The impact is too wide and clumsy and wooden mallets are waay better imo.

as to the sump, you never know! People find all kinds of goodies in there and it does no harm. Rock the engine around a bit and you may be -aah-rewarded?

But If you think it was in the clutch, I'm a little unsure why you're taking the pots off...? is there any chance the noise is those springs in the clutch-boss? ( I don't mean the actual clutch springs -the other ones) I have a bike that I think rattles those a bit. It doesn't affect the way I ride it so it'll wait.

So wood's the winner, eh? Maybe I'll head down to the Homeless Despot this week and grab one for my whacking purposes. I really do think it's just this crusty old gasket holding it on. Either it's the factory gasket being held by sheer crust or someone has replaced it at some point and used some crazy ass sealant (damn Indian lacquer!).

As for why I'm pulling it apart, it's mostly out of over-caution. I could still hear the noise when probing the bottom of the crankcase where the oil sump is and the noise didn't change at all regardless of clutch position so I assumed it wasn't directly tied to the clutch itself, though I have certainly been wrong before.

I haven't taken the clutch housing off yet so I don't know the second set of spring you're referring to. Are those underneath?

[Gorminrider]

So wood's the winner, eh? Maybe I'll head down to the Homeless Despot this week and grab one for my whacking purpose...

Your method isn't working and I'm merely suggesting a different technique, harmless to try.
Buy? don't Buy. At least don't buy a blisterpacked and degenerate iteration of a very simple tool until you know you really want it.
No hammer? find a nice rock. and so on...

Cut a scrap broomstick, or a straight branch of a trees, or a 2x2 or a 1x2 of stout wood to say 12 or 18" , and whack it with a steel hammer. The idea being you can apply more force at a smaller spot without marking the engine or accidentally, say, breaking fins off... Plus you can get target cramped places where that's wanted someday.
Mallet? a chunk of 2x4 or thick branch. More elaborately, a piece of short-grained wood that won't split right away, drilled to put a handle into. Some homemadse will fall apart in your hands after a few uses, some will be your lifelong friend...

[Gorminrider]

clutch GS400C.jpg

see the 6 springs? (black arrow)I called this "the clutch boss" for lack of imagination but the parts diagram calls it 'clutch gear. It's just a thought, per your description though.

[ItsBork]

[ATTACH=CONFIG]63467[/ATTACH]

see the 6 springs? (black arrow)I called this "the clutch boss" for lack of imagination but the parts diagram calls it 'clutch gear. It's just a thought, per your description though.

I just got to these today. I checked my actual clutch springs and they are 1mm out of minimum spec but the manuals don't list any specs for these springs on the back. There are two separate kinds in alternating pattern.
Any place I can find specs for these? None of them seem particularly loose.

[Gorminrider]

No though it might be in a shop manual somewhere...twas just a thought. Taking the motor of a running bike entirely apart to find an indefinite noise is beyond my experience. ..... you didnt find any other suspects in there? loose keyways? small bolts flicking around?
Maybe taking the sump plate off is the next. Or double-checking the cam-chain tensioner. Perhaps the chain was slapping. Have a look down the tunnel for sign of that. Have a good look at the camchain blade too. Pieces can come off the plastic ones- they are getting really old these days.

Usually you can troubleshoot worn bearings or rings or valves before you take the cylinders off.

If you're still determined to rip your cylinders off (which I'm not imagining as a discovery method for a knocking or rattling) and really can't find any reason for them not to release, I guess a wood-chisel whacked at the gasket all-round is the final blow. It's better than a screw driver. But it's so easy to mar surfaces and I didn't tell you to do it and I wouldn't until I'd determined it was all sacrificial...

[ItsBork]

No though it might be in a shop manual somewhere...twas just a thought. Taking the motor of a running bike entirely apart to find an indefinite noise is beyond my experience. ..... you didnt find any other suspects in there? loose keyways? small bolts flicking around?
Maybe taking the sump plate off is the next. Or double-checking the cam-chain tensioner. Perhaps the chain was slapping. Have a look down the tunnel for sign of that. Have a good look at the camchain blade too. Pieces can come off the plastic ones- they are getting really old these days.

Usually you can troubleshoot worn bearings or rings or valves before you take the cylinders off.

If you're still determined to rip your cylinders off (which I'm not imagining as a discovery method for a knocking or rattling) and really can't find any reason for them not to release, I guess a wood-chisel whacked at the gasket all-round is the final blow. It's better than a screw driver. But it's so easy to mar surfaces and I didn't tell you to do it and I wouldn't until I'd determined it was all sacrificial...

To be honest at this point the only reason I'm still determined to get the cylinder off is it will make it easier to de-carbon the pistons without getting shmutz all in the cylinder/case and before I cracked it open the compression was at about 90 psi. Haven't noticed any issues with the valves or seats, tappet clearances were acceptable. If it wasn't for the low compression I probably would have started with the clutch. But I already have a new set of rings sitting around and I certainly don't mind taking things apart even if it just ends up being for the experience. Sure, it might seem silly to be tearing the thing apart now, but I either find nothing and I learn a ton about my engine in the process and also end up with the peace of mind of knowing nothing is actually broken, or I find something broken and the end result is the same.

But yeah, if it wasn't for the low compression I would probably just be putting the head back on at this point.

[Gorminrider]

ah. 90# is low especially if it's just one side. But the valves affect compression too. Bad rings would result in fouled plugs and smoke, bad valves not so unless the seals were pretty bad? ...anyways I" did-over" the valves on my gsx400E, found bent ones and it fixed the "one-side low" problem.

[ItsBork]

ah. 90# is low especially if it's just one side. But the valves affect compression too. Bad rings would result in fouled plugs and smoke, bad valves not so unless the seals were pretty bad? ...anyways I" did-over" the valves on my gsx400E, found bent ones and it fixed the "one-side low" problem.

Both sides were low. I was debating borrowing a valve spring compressor and removing them to fully examine them.

[Nessism]

Have you popped the cylinder loose yet? We are going on 8 days now. It ain't that hard.

[ItsBork]

Have you popped the cylinder loose yet? We are going on 8 days now. It ain't that hard.

No I haven't. To be fair I have only been working on it in passing time.

I really am running out of ideas. I tried jammed a plank under the block where the cam chain tensioner goes and lifting, but no dice.

This definitely shouldn't be this hard which is getting frustrating because it feels like I'm missing something. Yeah the gasket is old but if there's nothing else holding it I shouldn't have seen SOME progress by now, even just a lifted corner or something.

I could have the whole bike put back together in an afternoon if I can just get this damn cylinder off so I can clean the Pistons and change the rings.

[Nessism]

How about a crowbar? Use duct tape on the tip so it doesn't gouge the aluminum. Cram it in the gap between the tab that stick out and the block and then lift up.