The definitive how-to install the valve cover and gasket


Postby daves79x » Tue Apr 06, 2010 5:25 am

Mike:
Our old printed fiches show 90451-422-000 as the part # for the '79 only. 90453-422-000 shows as the # for the '80. 90453-422-003 is the '81 and 90453-MA2-000 is the '82. I'm telling you that the last 3 #s I listed all superseed to a current Honda part # of 90453-MA2-000. I just bought a set for an '80 I'm doing and that's the # on the bags of grommets.

So there are only 2 current valid Honda part #s for grommets - 90451-422-000 for the '79 only and 90453-MA2-000 for the '80-'82.

I have owned all four years of CBXs and only the '79s have the smaller grommets. Nils even notes that the '80 he is restoring had the larger grommets when he removed them.

I call the '81-81 valve covers polished and clearcoated as opposed to the obviously painted '79 and '80. If your '81 is painted, Mike, then it is not a factory finish. Not sure where the confusion is there?

Dave
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Postby EMS » Tue Apr 06, 2010 7:38 am

Dave, I am sure you know that the way the Honda part-number system works is: 90453-422-000 and 90453-422-003 are the same part. 90453-MA2-000 is different. The fact that the last number superceded the others just means that this is the only one available as a replacement.
But your listing confirms to me, that only the 1982 had a really different grommet. What the difference between 90451-422-000 and 90453-422-000 is, I don't know, but I will get to the bottom of this as soon as I find a way to read my microfiches. If the 1980 grommets would have been different from 79s from the factory, they would have had a -469- part number. Also the verdict is still out, whether the 80 had a different valve cover with a different part-number from the 79.

And as far as "polished" is concerned, it's just what you decide to call the stock Honda cover. I don't consider the clearcoated part "polished". The one on my 81 is polished now, but it cost me $100.- to get it there.
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Postby EMS » Tue Apr 06, 2010 8:07 am

An early morning phone call to Mr. Coe and succeeding in convincing him to get him in front of his microfiche reader yielded the following:

Valve cover for 1980 CBX is part-number 12311-422-010. (Please note the 1979 product code!)
Two different part-numbers are listed for 1979: 12311-422-000 and 12311-422-305.
Based on my experience with the Honda part-number system, it is my opinion (shared by Mr. Coe) that these valve covers are all the same.
The variation in the last 3 digits usually denotes a different supplier or a different finish, but not a different part.
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Postby daves79x » Tue Apr 06, 2010 11:56 am

Mike:
This is really not arguable, except for the goofy way Honda made the part #s. I have right here a '79 valve cover and an '80 valve cover side-by-side. They ARE different, regardless of what the part #s say. The '80 has much broader, perfectly flat platforms on which the grommets snug down on - which is exactly how the '81-'82 covers are. I'm standing by my personal observation of lots of them that the '80 and '81/'82 covers are exactly the same except for finish. I'll send you photos if you want.

If you accept the above, then it follows that only the large grommets go with the '80-'82 covers, again, regardless of what the fiche says. I'm telling you that if you order grommets for an '80, you get the MA2 part #. Originally there may have been minute differences in the large grommets from the factory year-to-year ('80-'82), but when they finally settled on a bolt length and grommet size, they came up with the MA2 number as the correct replacement for ALL '80-'82s.

In this case the Honda part #s are betraying you, I think.

Dave
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Postby EMS » Tue Apr 06, 2010 12:03 pm

Dave, you are still talking about "replacement" and I am not arguing with that. I am just not sure what was "original". And Honda's part-number system is pretty reliable.
If the 1980 valve cover was new and different other than the finish from the 79, the part-number should have had a -469- in it. If the Prolink valve cover was the same as the 1980s except for the finish, the part-number should not be an MA2 number, but a 469 with a suffix behind it.
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Postby daves79x » Tue Apr 06, 2010 12:38 pm

Mike:
OK. But asking for the original rubber grommets (if there actually were ever any real differences) for your '80-'82 is like asking for the original air in your tires - they are not available and likely never were. Rubber parts, or any wear part has to be replaced sometime, and this is what Honda is using for us to keep these things running. I'm perfectly sympathetic to the faithful restoration if original parts are available, new or used, but these aren't, so it's a moot point.

By the way, if you look at the Honda Code # for those valve covers, they are completely different - Honda, back in the day, used those code #s more than the part #s - that's the way you ordered parts.

Dave
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Done

Postby NobleHops » Thu Apr 08, 2010 9:23 am

OK, the update is that my gasket and OEM large grommets arrived yesterday, as hoped. Thanks Bill!

Just for fun I measured the thickness of the old and new gaskets and grommets, and both of the new components were a full millimeter thicker than the old ones, and of course the new gasket was nice and springy, as were the grommets.

I cleaned the channel on the cover on Monday night and flooded the channel with carb cleaner then dried it, till it was squeaky and spotless, left it to dry overnight. Last night I smeared a bead of sealant in the channel, installed the gasket, waited an hour for it to set up, and with a small putty knife holding the gasket in place as I worked it over the troublesome oil pipe, it slipped in fairly easily. Put a dot of sealant at all the cam end cap corners as prescribed, and then installed the bolts, tightening the centers first, then the ends. Buttoned it all up and left it till this morning to seal up, which apparently it did.

I ran it on the lift for a few minutes, and it is tight. Hallelujah. :rocker:

Thanks a ton guys.

N.
I Do Vapor Blasting! http://www.cbxclub.com/forum/viewtopic.php?f=5&t=9881

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http://www.restocycle.com Ikon shocks for your CBX! https://www.ikonshocksusa.com/collections/honda/honda-cbx1000-79-80
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