Valve Cover Gasket

[jsmith800]

Hi all, trying to install the valve cover gasket (long crazy spaghetti shaped gasket) and it keeps slipping out at different spots when trying to install it in the valve cover. any suggestions. i've warmed up the gasket in water but still feel like its too small or something. i've even taped it in with duct tape but when i slowly remove the tape it pops out again.

its called GASKET, CYLINDER HEADCOVER 12391-426-00

it came as part of a gasket kit i purchased from ebay. I'm guessing a crappy Chinese knockoff that not correct.

really getting frustrated.

[jsmith800]

i got it. used contact cement to hold that gasket to the head cover before installing. engine complete and ready to reinstall!

[Volker_P]

What caught my eyes first is that everything is very, very clean.

I have some more specific comments, too:

For replacing the head cover bolts by others it is important to have the correct length. Some bolts are expected to carry copper washers. If you have harder washer material it might not become tight like that. More torque is always a bad idea for head and head cover bolts.

Another point is the rocker axle cotter bolts. On the left rear a lot of its thread is visible compared to the others. One possible reason is that the head cover is cracked on the bottom side so the cotter bolt head can go in deeper. Basically this should not cause too much trouble as the rocker axle is still fixed and cannot go anywhere. But I have seen head covers that are cracked there and as a consequence the bottom side of the head cover was not flat there any more. As you have everything together now I would give it a try like that. But if you have a oil leak at the center of the engine at the head cover level it is probably not due to the poor gasket.

BTW, I remember that in the 1990s I returned exactly that gasket that I bought in an original Honda plastic bag at the local Honda dealer because it had pimples all over the surface! So you not necessarily got crappy Chinese stuff. My solution at the time was to make my own seal from a 3.5x1240mm rubber cord.

[jsmith800]

thank you volker_P. i'm will certainly monitor the rocker cotter bolts situation for oil leaks at the valve cover center area, i did notice during install of that one of the cotters seated rather deep while the other 3 did not, i summed it up as a machining issue in the factory. wish i would have known of a potential crack earlier and looked closely for it. oh well rockers are not adjusted and covers installed.

today is install day, I'll remove the lower right frame section then install with a floor jack under the pan while the bike is on the center stand. from reading the floor jack should roll the engine in then slightly to the rear.

Heres my engine removal, cleanup and reassembly images if interested:
https://photos.app.goo.gl/XfHZ1fekfsh2w8xg8

Heres last years build...the 79 bike was too beautiful to destroy and create a cafe racer:
https://photos.app.goo.gl/mscR7EyFMc71LWdn7

[Volker_P]

You have a very impressive collection of pictures with lots of details.
Almost every part can be found. And everything is that shiny.
I can imagine that this was really a lot of work. I used to restrict intensive cleaning to the really important surfaces.

Good luck for the cotter bold issue.

[jsmith800]

Hi All.

Bike reassembled and fired nicely and sounds good for a bike that needs to be tuned yet. Sadly noticed a oil leak near the countershaft for the sprocket. not good!

oil must spin violently in this area because the leak starts almost immediately after firing the engine.

i've got the engine half disassembled again to search for the issue. i had the engine vapor honed and honestly think there is a grain of sand in that bearingset channel.. Won't know till i get it out for inspection. I used anaerobic Permatex 51813 durring case mating....very sad at the moment.

i thought of shop mechanics who have this problem and have to completely rebuild the engine and NOT get paid double for labor. thankfully this is my nightly hobby so not a huge deal.

attached a few pics of the leak, pics of new pistons after running for 10 minutes and pic from the inside of the case in the direction of the leak.

I WILL be using Honda Bond 4 the second time around.

Hay Volker_P this will give me a chance to inspect the rocker axle cotter bolts! (thinking positive)

[jsmith800]

Those black chunks in the case are NOT dirt and grime, its assembly lube with moly-graphite.

[Volker_P]

Sorry to read about the oil leak.

At least everything is still clean. I would reuse all gaskets in this case.

BTW, if it were not for the cotter bolt issue, one could split the engine case without removing the top.

Strange position for an oil leak. Probably not simply "sealant failure".
Check case surfaces on both sides for possible warp (e.g. place them on a mirror) and have a close look on this half ring for the bearing set.
Also measure bolt threads for depth with a longer bolt before reinstallation of case bolts.

Good luck!

[jsmith800]

Hay Volker_P

Damn, didn't think about that! would have saved time. i also thought i could save time by NOT removing the pistons from the connecting rods....also learned that's NOT possible, they won't fit thru the slots between main bearings.

ok so i believe i found the problem after inspection..90% sure anyhow. the anaerobic Permatex lost adhesion to the case i believe due to me spraying
compressed air down that hole during the build last week, there was crud or gunk or sand in the hole from vapor honing process way at the bottom of that longest bolt hole i couldn't get out so i used compressed air to push it out. i believe compressed air took the path of least resistance and went passed the newly applied sealer thus eliminating proper setup. if you look at the image, the Permatex surrounds that long bolt hole and you can see by the color there was NO seal happening there which allowed case oil to get out.

Sure am learning a lot here. still thankful i don't have to charge for this job...I'd clearly loose money.

I ordered Hondabond a few days ago, give me your thoughts of Hondabond vs Permitex 51813. at this point i'd do which ever provides better sealing properties.

Permitex 51813 cleanup is great, almost feels like a pliable vinyl and peals right off.

[Volker_P]

... the anaerobic Permatex lost adhesion to the case i believe due to me spraying compressed air down that hole during the build last week, there was crud or gunk or sand in the hole from vapor honing process way at the bottom of that longest bolt hole i couldn't get out so i used compressed air to push it out.

I see.
I can imagine that your compressed air effort blew some debris between the two halves of the case and the fresh sealant caught it there.

It is a very basic rule to turn in every bolt one after another in its place by hand before even considering to place sealant somewhere. This way you get an idea if the threads are still fine and clean really down to their bottom.
The problem of cleaning by machines is that parts always look perfect at the first glance but you can easily overlook the really important details in corners and holes.

Anyway I see very much sealant there. There is even something like a bubble between the bolt hole and the nose that holds the bearing. I really recommend to check that corner for being flat again.
The case basically requires "zero" sealant thickness as it adds to the narrow crankshaft bearing oil gap.
I typically use Hylomar very sparingly there (and everywhere else where it makes sense, too).

Good luck!

[jsmith800]

Honda Bond 4 applied, cases mated & torqued to spec.

Next put in the engine stand and add cylinders. Beer can aluminum & hose clamps seem to work for the ring compressor. Will need help on this step.