Author Topic: Case Gasket (Read 2952 times)

RebelSkyRot · « **on:** October 30, 2012, 05:13:50 AM »

So I've gotta split the engine case on my 74 cb750K, is there somewhere I can get a new gasket for the case once I put it back together or is it okay to use gasket maker?

ekpent · « **Reply #1 on:** October 30, 2012, 05:21:19 AM »

There is no gasket for the case halves so a sealer is used. Others will have a good recomendation I'm sure. What do you have to do in there ?

jtb · « **Reply #2 on:** October 30, 2012, 05:41:05 AM »

Yhree Bond 1104

RebelSkyRot · « **Reply #3 on:** October 30, 2012, 06:00:29 AM »

Well I'm doing a top end rebuild and, uh, while I was taking piston 2 out one of the C clips shot into the case...

I tried digging around with a magnet stick but that didn't work so apart the cases come!

MCRider · « **Reply #4 on:** October 30, 2012, 06:03:21 AM »

GasgaCinch is a favorite, also.

Key is you want "non-hardening" non-silicone type. Apply thin coat, let sit several mintutes to get tacky, assemble.

http://gasgacinch.com/

skidooextreme · « **Reply #5 on:** October 30, 2012, 06:10:03 AM »

Hondabond...yamabond. and the others people have mentioned. Around 10 bucks

RebelSkyRot · « **Reply #6 on:** October 30, 2012, 06:19:23 AM »

@MC So thin as in just enough to cover the entire surface? Like applying wood glue?

MCRider · « **Reply #7 on:** October 30, 2012, 06:23:26 AM »

Quote from: RebelSkyRot on October 30, 2012, 06:19:23 AM

@MC So thin as in just enough to cover the entire surface? Like applying wood glue?

Yup. That's all. Incl the saddle posts at the crankbearings. Not so much that it drips and runs, just covers.

ekpent · « **Reply #8 on:** October 30, 2012, 07:58:48 AM »

Quote from: RebelSkyRot on October 30, 2012, 06:00:29 AM

Well I'm doing a top end rebuild and, uh, while I was taking piston 2 out one of the C clips shot into the case... I tried digging around with a magnet stick but that didn't work so apart the cases come!

Have you tried shooting in some air from a compressor maybe and then remove the oil pan on the bottom of the engine to see if you get lucky and have it fall through to the bottom. Big job for such a small little piece.Wonder if that little clip is capable of really doing much in the way of damage anyways ?? Thoughts anybody---

RebelSkyRot · « **Reply #9 on:** October 31, 2012, 06:04:37 AM »

Quote from: ekpent on October 30, 2012, 07:58:48 AM

Quote from: RebelSkyRot on October 30, 2012, 06:00:29 AM
Have you tried shooting in some air from a compressor maybe and then remove the oil pan on the bottom of the engine to see if you get lucky and have it fall through to the bottom. Big job for such a small little piece.Wonder if that little clip is capable of really doing much in the way of damage anyways ?? Thoughts anybody---

I might have to try that! I've been stalling for a week now to split the case because I'm in no way looking forward to it and that sounds much easier!

MCRider · « **Reply #10 on:** October 31, 2012, 06:14:53 AM »

The air could work.

In the meantime I'll share a trick. Put a thick, like a#3 Phillips screwdriver in the piston pin hole before messing with the clips. That way if one gets away from you it will circle harmlessly on the shaft of the driver.

Also, stuff the area under the piston with shop rags. Belt and suspenders.

RebelSkyRot · « **Reply #11 on:** October 31, 2012, 06:21:39 AM »

Thanks for that tip, I'll definitely remember that for the future!

RebelSkyRot · « **Reply #12 on:** November 01, 2012, 05:34:27 AM »

I took the oil pan off yesterday and found a decent size chunk of casting in it. So now I'm really thinking, if that can make it through the engine, how much could a 15mm C-clip do?

ekpent · « **Reply #13 on:** November 01, 2012, 05:52:06 AM »

You say you found a chunk in there. Were there many other shavings etc. Always good to put a magnet to that stuff just to get a good idea as to what it is. Have any pictures by chance,fun to figure out what it may be. Some interesting stuff has turned up down there,broken rings people have dropped etc. Personelly speaking I don't think that piston clip would kill your engine but never fun knowing something is floating around down there.

MCRider · « **Reply #14 on:** November 01, 2012, 05:56:10 AM »

Quote from: ekpent on November 01, 2012, 05:52:06 AM

You say you found a chunk in there. Were there many other shavings etc. Always good to put a magnet to that stuff just to get a good idea as to what it is. Have any pictures by chance,fun to figure out what it may be. Some interesting stuff has turned up down there,broken rings people have dropped etc. Personelly speaking I don't think that piston clip would kill your engine but never fun knowing something is floating around down there.

One can never suppress the paranoia, but as a practical matter, once something gets to the sump, there's not much else for it to do. Things just don't drift around in the engine, they find a spot and settle down.

As far as a chunk? Would be nice to know what is.

But getting there, the clip could get in the chain/sprocket continuum I suppose.

RebelSkyRot · « **Reply #15 on:** November 02, 2012, 03:43:58 PM »

The chunk I found was the bottom piece of one of the cylinder studs. I would give you guys a picture but I'm not quite sure how to post one on these forums... @ekpent, there were also a lot of tiny metal shavings, kind of looked like my bike my panning for gold

Music City Metalcraft · « **Reply #16 on:** November 02, 2012, 08:37:38 PM »

Back in the day (and maybe still today?) aircraft guys used silk thread between the cases as a sealer. If it would nt be such a mess to redo in case it doesn't work on the Honda cases...
Just imagine, silk thread from a kamikaze pilot's scarf...

RebelSkyRot · « **Reply #17 on:** November 05, 2012, 05:21:34 AM »

I decided against splitting the cases, but my auto teacher thinks I should pressure wash inside the engine then spray it all over with wd40, whaddya think about that?

ekpent · « **Reply #18 on:** November 05, 2012, 05:35:31 AM »

Bad idea. Pressure washing with water in there will force to much water into bearings and other bad places and the WD40 will not have the 'pressure' to force it out.

MCRider · « **Reply #19 on:** November 05, 2012, 06:01:06 AM »

Quote from: RebelSkyRot on November 05, 2012, 05:21:34 AM

I decided against splitting the cases, but my auto teacher thinks I should pressure wash inside the engine then spray it all over with wd40, whaddya think about that?

"Inside the engine"? I don't see how or why one would want to do this.

lucky · « **Reply #20 on:** November 05, 2012, 06:28:14 AM »

Buy the real deal, Gaskacinch case sealer. Why buy a copy cat like Yamabond or Honda bond.

Put a light coat on each case half, then let dry. assemble.

lucky · « **Reply #21 on:** November 05, 2012, 06:35:52 AM »

Quote from: Music City Metalcraft on November 02, 2012, 08:37:38 PM

Back in the day (and maybe still today?) aircraft guys used silk thread between the cases as a sealer. If it would nt be such a mess to redo in case it doesn't work on the Honda cases...
Just imagine, silk thread from a kamikaze pilot's scarf...

Be careful, when you say these things on the internet some inexperienced person might actually try it and ruin the engine rebuild. They would have to redo it all.
Including taking the engine in or out. Also that silk thread could cause a case to get warped or cracked when the pressure of the case bolts is applied.

Japanese engine cases are very precision and you want the cases to fit tight.
No leaks.

lucky · « **Reply #22 on:** November 05, 2012, 06:38:14 AM »

Quote from: RebelSkyRot on October 30, 2012, 06:00:29 AM

Well I'm doing a top end rebuild and, uh, while I was taking piston 2 out one of the C clips shot into the case... I tried digging around with a magnet stick but that didn't work so apart the cases come!

That is NOT necessary.

Just look in the sump by taking the bottom pan off. And if needed remove the clutch cover and you can see everything. Make sure the clip is not on the floor in your work area.

Music City Metalcraft · « **Reply #23 on:** November 05, 2012, 09:10:12 AM »

Quote from: lucky on November 05, 2012, 06:35:52 AM

Quote from: Music City Metalcraft on November 02, 2012, 08:37:38 PM
Back in the day (and maybe still today?) aircraft guys used silk thread between the cases as a sealer. If it would nt be such a mess to redo in case it doesn't work on the Honda cases...
Just imagine, silk thread from a kamikaze pilot's scarf...

Be careful, when you say these things on the internet some inexperienced person might actually try it and ruin the engine rebuild. They would have to redo it all.
Including taking the engine in or out. Also that silk thread could cause a case to get warped or cracked when the pressure of the case bolts is applied.

Japanese engine cases are very precision and you want the cases to fit tight.
No leaks.

Lucky,
I cannot see why you feel the need to tell me to be careful with what I say. We are all adults here, and I don't see how anything I wrote could bring anyone in trouble. If you dig that deep into an engine, you should know what you do, otherwise leave it to someone who knows.
If you only think for a second about how thick a silk thread is, you would figure out that there would be at no point any danger to the cases. It is just a very old school way of sealer, before there was any chemical replacement. And aircraft cases are surely not less precise than a mass produced motorbike case...
On top of that there is less danger of excess sealer squishing out and clogging oil passages with a silk thread.
So peace, and be open to things you may not have heard of or understand...

MCRider · « **Reply #24 on:** November 05, 2012, 09:22:11 AM »

MCM: You just bumped into a Luckyism.

For example i recommended GasgaCinch in reply #4. Lucky felt the need to repeat it in reply #20.

After several posts to corect his spelliing (and the correct spelling on his picture of the can) I gave up. He still calls it Gaskacinch.

ekpent · « **Reply #25 on:** November 05, 2012, 10:41:59 AM »

Quote from: lucky on November 05, 2012, 06:38:14 AM

Quote from: RebelSkyRot on October 30, 2012, 06:00:29 AM
Well I'm doing a top end rebuild and, uh, while I was taking piston 2 out one of the C clips shot into the case... I tried digging around with a magnet stick but that didn't work so apart the cases come!

That is NOT necessary.

Just look in the sump by taking the bottom pan off. And if needed remove the clutch cover and you can see everything. Make sure the clip is not on the floor in your work area.

Also a good idea to read the whole thread. He has already removed the oil pan.

RebelSkyRot · « **Reply #26 on:** November 06, 2012, 05:39:30 AM »

Thanks for the replies, I'm not going to pressure wash it, even though my auto teacher is convinced it'll all be fine with wd40.... Also, not related to my original question but I might as well ask and not make a new thread, when I was riding the bike the clutch was pretty hard to squeeze - after a few days I was starting to get blisters on my fingers. Any ideas what would cause this? One guy said on another forum that I just need to lube my cable but I really don't think that's the cause, is there anything in the clutch assembly that can wear out and make it hard to engage/disengage?

City Boy · « **Reply #27 on:** November 06, 2012, 06:07:01 AM »

Hi.I also think your stiff clutch is likely caused by dry or improperly routed cable. I cannot think of anything internal to cause this unless clutch has been assembled wrong to begin with. Rock On

RebelSkyRot · « **Reply #28 on:** November 06, 2012, 06:21:59 AM »

Really? Huh I didn't think just an unlubed cable could cause that much stiffness but hey I'll give it a go when my engine's back together!

MCRider · « **Reply #29 on:** November 06, 2012, 06:35:51 AM »

Quote from: RebelSkyRot on November 06, 2012, 06:21:59 AM

Really? Huh I didn't think just an unlubed cable could cause that much stiffness but hey I'll give it a go when my engine's back together!

+1 cityboy

Rebel: I'd give it 95+% its the cable. Not only may it be dry, or poorly routed. It may simply be shot. If its old in chronological time, even if it hasn't been used much, it corrodes internally. This occurs with the passing of time, temperature cycles, condensation cycles. The braid of the cable, or sheath if its sheathed, rubs against the inside of the outer cable and there can be quite alot of friction there. You could even remove the cable, lube it and it feels fine. But when you reinstall it and put a load on it, that's when the friction occurs. At some point, nothing except a new, preferably Honda, cable will fix it.

The internal lifter under the clutch cover is constantly oiled and made of very tough stuff.

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Author Topic: Case Gasket (Read 2952 times)