Topic: I guess it's a bad idea to change my valve cover gasket in frame (edit)

[78CB750CAFE]

Seems I have a leaky valve cover gasket
I have an oem valve cover gasket on the way from the local dealer, as well as 8 new valve inspection cap O-rings, and a full SS bolt kit from ebay waiting in the wings.
Can I do the gasket swap with my engine still mounted in the frame, or is it time to yank that puppy out???

Drew

[TwoTired]

Sawsall or engine unit removal. The former not recommended.

[Gordon]

Apparently it's possible to replace the valve cover gasket with the engine in the frame, but I've never done it myself.  You can't remove the valve cover, but you can lift it up enough to get the old gasket out and then slide the new one over the top. 

My biggest concern with this method is making sure to get every last tiny piece of the old gasket out of the groove before installing the new one.  If it's old and brittle, chances are some bits will tear off and stick in the groove. 

[Gregorymoto]

No it will not go on with the motor in the frame, you need to pull the motor.

[Gordon]

No it will not go on with the motor in the frame, you need to pull the motor.

There are some who would differ.  Namely Oldfart who wrote:

"Well, I can tell none of you guys worked in a Honda shop back in the 70s.  It was common for techs back then to replace the valve cover gasket on the CB750 with the engine in the frame, and beat Honda up on the factory flat rate at the same time, of course.  So, yes, it can be done.  The gasket will spread over the valve cover, and as long as too much scraping of the head isn't necessary (to remove the old gasket) then a new one can in fact be put on in the frame.  I have done it, and I have seen it done.  Unfortunately, that is about all you can do. "

Taken from this previous topic on the same subject.  http://forums.sohc4.net/index.php?topic=15529.0

[Gregorymoto]

Ok if you are using Goo gasket ya OK you can, but if you use the OEM fiber gasket you need to unbolt it and get the cover off.
I would use loctite gasket if you want to use a Goo.

[78CB750CAFE]

Thanks guys.

I pulled my tank earlier and came to the conclusion she is comin' out if I want to do this right. Thank god it is starting to look a little like winter so I don't feel so bad about putting her out of commision for a week or 2. I pulled my exhuast and capped the openings, and pulled off my clutch cable, throttle cables, tach drive, shift lever, kick start, and brake switch spring in prep. I guess my carbs will go next, hopefully I have some plugs around that will fit the intake openings too. I have my buddy coming over saturday night and the wife and kids out of the house for the night for the grand removal. That gives me 3-4 nights this week to do the rest I need to do before pulling it out. Looks like a ton of fun 

While I have the lump out, what else should I try and do?? I plan on high polishing or painting the valve cover while I have it off, and I am tempted to paint the lower end too since it looks pretty shabby thanks to a couple of long standing gas puddles under the petcock and carbs all but obliterating the paint below it while in the hands of the PO. Any other fun projects (short of cracking the block open) I should tackle while I have a 2 piece set instead of a proper motorsickle?

Drew

[shoemanII]

just a quick note about the valve cover gasket orientation:  if it's not perfectly lined up and you think it might need to be pushed around just a very small smidge - flip it over.  even tho it looks like  all the "stuff" in there is symetrical it's not.  depending on miles, might want to look at your cam caps, all the rocker assy and cam chain sprocket fasteners (i found a loose bolt).  adjust your valves then too - it's so easy you may do it twice just because.  might also want to look at your "pucks".  i just did a base gasket to valve cover gasket job and found my pucks to be dished out.     
bobp

[bryanj]

Tacho drive oil seal as its way easier with the cover off

[upperlake04]

might also want to look at your "pucks".  i just did a base gasket to valve cover gasket job and found my pucks to be dished out.     

 If you disassembled this far and have the camshaft towers off, a close inspection of the tiny metering holes in the oil jet orfices would bring peace of mind. Any crud build-up will diminish the amount of oil flow to the top end - not good - as my and many others personal experience can testify to. 

[shoemanII]

they "looked" fine but didn't poke anything in there, maybe i should have.  from the condition of the rocker caps they appear to be flowing fine.  she's all back together and being degreased w/a variety a stuff, next step is to grind a bit off the RH mounting flanges to make the install a bit easier.

(my first engine work, hope it doesn't go BOOM when i turn it over for the first time!)
bobp   

[ofreen]

While I have the lump out, what else should I try and do??

Retorque the head and install new seals under the cam holders.

[UnCrash]

they "looked" fine but didn't poke anything in there, maybe i should have.  from the condition of the rocker caps they appear to be flowing fine.  she's all back together and being degreased w/a variety a stuff, next step is to grind a bit off the RH mounting flanges to make the install a bit easier.

(my first engine work, hope it doesn't go BOOM when i turn it over for the first time!)
bobp    

Could you say more about what you are using to degrease your engine, and your successes with product/process?  I have just pulled my motor and will be doing the same.

Additionally I'm curious about the motor mount flange, is it this?  ____------>

[78CB750CAFE]

Great advice all, thanks. It is 36 degrees in my garage right now so I am not doing a thing tonight, but tommorow the oil gets drained and the carbs come off and then the real fun will begin 

When you guys have painted your engines, how far did you take them apart? I am wondering if I can just remove or mask the L side covers I polished and the chrome right side covers, mask off the jugs and spray away.... but what to do about the bolts surrounding the clutch cover and elsewhere I do not want painted over? Any ideas/experiences to share???

Drew
Suddenly a before pic...

[shoemanII]

to get the globs off from around the sprocket and heavy oily/crud from between the fins i'm using wd-40.  will finish off with carb clean near an open door. 

am going to take off maybe an 1/8 - 3/16 or so from the top of the mounting flange in the pic and a little off the rearward one.  i think it will make a huge difference.

i was pretty lucky:  PO told me he bought the bike from a guy in the midwest.  didn't believe him at first (a biker, after all!) but nearly rustfree and fasteners all came off easy.  inside the rims looked new - 
bobp   

[754]

I can see getting the old gasket out, but getting the new in is it hard?? never tried it..sounds tricky..

[ofreen]

I can see getting the old gasket out, but getting the new in is it hard?? never tried it..sounds tricky..

To me, it seems like the hard part would be getting the old gasket out and being confident that the mating surfaces were clean.  I've had the cover off twice now on my old 750 (engine out of the frame.)  Each time, the gasket came off without breaking because I used a little care, but even so, there were several  places where residue from the gasket had to be scraped off.