Topic: 76 CB750f top end o rings(help needed)

[stlal]

Heys guys...

First off I have used the hell out of the search function so please forgive me if this has been covered.  I can't find it.

I have a 76 cb750f and I am rebuilding the top end.

I have been looking at the micro fiche and see part number 12116-300-000 (12mm pins)  8 of them

I cant locate them on the cylinder

If some body can fill me in on all of the gaskets and o rings on the top end I will appreciate it.

Thanks

So far I know I have to replace these gaskets and rings

4 discs
valve cover
cam tensioner
2 orfices
base gasket
head gasket



Thanks in advance

[Kevin D]

I have used the hell out of the search function. I can't find it.

Some times I find stuff and then can't find my way back to it. . Search, history, you name it. But just keep looking around and you'll find plenty.

There are 6 of those sealing pucks.

Service bulletin #42 describing pins/seals from Technical Library at Main Page. Early engines don't have them.
http://sohc4.com/tiki-list_file_gallery.php?galleryId=2

Parts Resource from Forum FAQ:
http://forums.sohc4.net/index.php?topic=743.0

[stlal]

That service bulleten helps alot.

I knew there was six..not sure why I said 4


Thanks

[stlal]

I am having a hard time reading the micro fiche

Does anybody know/have a list of all the gaskets/orings needed from the base gasket to the rocker cover?

I have the athena gasket kit but I want to be sure every gasket and oring gets replaced.

Please  HELP!!!

Thanks

[J.Webster Designs]

anyone have a diagram similar to that for the orings and such for under the cam towers and in general the top of the head?

[gregimotis]

I did this job on my 76 cb750 f last year and took some photos and such.  will try to come up with some of that stuff.

[gregimotis]

Here you can see some of the o-rings in position on the cylinders and also the two brass tubes on either end too aid alignment:

[gregimotis]

And here is another view of the same thing.  The o-rings are in the realtive positions on the cardboard and one of the brass tubes is out:

[gregimotis]

I have some photos of the top also, but will have to get them later.

[78 k550]

I use Britt Honda My dealer out here.
go to there parts fiche.
http://www.brittpowersports.com/

Paul

[stlal]

And here is another view of the same thing.  The o-rings are in the realtive positions on the cardboard and one of the brass tubes is out:

Ok.. so you have a total of  10 o rings?

Do you have 8 12mm knock pins  with the 8 outside o rings and the 2 dowels pins?

[J.Webster Designs]

gregimotis if you dont mind posting those pics as well i would appreciate it.

[Gamma]

Hope this is useful
http://i192.photobucket.com/albums/z293/galaxy8155/DSC02116.jpg[/img]]

[gregimotis]

Gamma's pic and mine are essentially the same for the top end.  You see the six pucks and the four little o-rings which all go under the cam towers, and the six or so brass 'tube thingy's which help line everything up.


And yes, ten underneath : two o-rings, eight o-ring like inserts, and the brass tube-thingy's

Midnight, the two center 0-rings which go between the cylinder and head look like the o-rings you have left over in your other thread... maybe they belong there?

[J.Webster Designs]

they are too small and i have those O-rings in there. im not sure where they go. are there o-rings for the cam chain tensioner?

[gregimotis]

they are too small and i have those O-rings in there. im not sure where they go. are there o-rings for the cam chain tensioner?

Negative, just the gasket.  Now that I think about it, I seem to recall having a couple small o-rings left over as well... I'll check my 'extra parts' cup tonight and see what I find in there.

[J.Webster Designs]

thanks

[gregimotis]

I don't have the o-rings to prove it but I'm pretty sure I had two left over as well.
They were a little larger than those four which go under the cam towers.  At the time I hadn't removed the jugs, so I decided they probably belonged down there somewhere.  1500 miles later and no troubles.

I got my kit from Cycle-X.  You could call your supplier and ask about it, maybe they fit a different year or something.



Sorry, I can't answer definitively.

[J.Webster Designs]

mine came from cycle-x as well. how has your kit been holding up?

[gregimotis]

Here's my thread - you'll notice most of the trouble I had came from trying to be cheap and not taking good advice.

http://forums.sohc4.net/index.php?topic=35937.0

my kit was allright, although in the end I purchased base, head, and valve cover gaskets from Honda.  Partly because the valve cover gasket did not fit - although I hear this is not typical of kits from Cycle-X.

[stlal]

Here is my gaset kit.

Can anybody identify all these orings?  I labeled them by line for easy explanation

Also there is a pic of my cylinder...I think is came from a K model since there is no way to install the 8 knock pins...I am assuming I just place the orings along with the head gasket?

Any help will be very much apreciated.

Thanks

[chippyfive50]

Hot Topic...I just posted the same question this morning. My 74 750k4 does not have the 12mm pins and seals, just the 2 dowels, 2 o-rings and head gasket. Then on the top, the pucks and 4 o-rings under the cam towers...

http://forums.sohc4.net/index.php?topic=45701.0

[stlal]

Is it possible I have  K model jugs?  I know I do have K pistons

I am sooo confused

[stlal]

Ok...after comparing my cylinders to yours it seems mine is something different that a 76 F model, My cylinder head is marked F and the engine number is F.

Any ideas?

It is bored 1mm over and everything else seems to be in good shape.

[Kevin D]

Is it possible I have  K model jugs?

Yep, your cyl doesn't have the cutouts for the return oil seals (#3 in your pic).

As for those other o-rings, you should measure them and compare to parts fiche. Did you get a list with your gasket kit? Did you get a complete kit or a top end kit? Looks like you might have stuff for the bottom end too.

Can anybody identify all these orings?

         
Just guessin' now - dont take this to the bank. Check the measurements to be sure.
#4 top end oil feed (2 studs at center rear of cyl).
#6 under cam towers
#7 big dowel between cases or neutral switch
#8 oil pump and hoses
#10 oil cap above points
#11 trans oil feed passage near shift linkage

[stlal]

Is it possible I have  K model jugs?

Yep, your cyl doesn't have the cutouts for the return oil seals (#3 in your pic).

As for those other o-rings, you should measure them and compare to parts fiche. Did you get a list with your gasket kit? Did you get a complete kit or a top end kit? Looks like you might have stuff for the bottom end too.

Can anybody identify all these orings?

         
Just guessin' now - dont take this to the bank. Check the measurements to be sure.
#4 top end oil feed (2 studs at center rear of cyl).
#6 under cam towers
#7 big dowel between cases or neutral switch
#8 oil pump and hoses
#10 oil cap above points
#11 trans oil feed passage near shift linkage

I have the Athena complete gasket kit.  I figure I will have extras since i'm not splitting the cases.

What should I do about the cylinder...nothing was there in the 8 spots when I removed it...should I get some o rings or just leave them empty?

[Kevin D]

What should I do about the cylinder...nothing was there in the 8 spots when I removed it...should I get some o rings or just leave them empty?

Depends on your head gasket........ I tried to get the parts from Honda that were numbered in that service bulletin, but it proved to be a dead part number. If it has small holes like the first pic then orings won't it.
 I got a HG with the bigger holes and fitted viton quad rings. One year, 3000 mi later......no leaks. But I'm not totally comfortable with it as those knock pins are there for a reason... to keep the oring in place.

[stlal]

Ok my head gasket has the bigger holes...

Do you know what size viton rings to use and where to get them?

Does you think this can cause any other problems?

Thanks Kevin!

[Kevin D]

-014 size, Small Parts Inc.

http://www.smallparts.com/Minnesota-Rubber-Black-Viton-Quad-Ring/dp/B0018YWV0Y?ie=UTF8&pf_rd_r=0TQR2J5VMCKK2E0CV8M2&pf_rd_p=467590051&pf_rd_i=16413611&pf_rd_s=center-3&pf_rd_m=AIUBT5HP6PMAF&pf_rd_t=101

Do you think this can cause any other problems?

Worst case possibility - the oring gets squeezed into the hole it is supposed to seal and blocks the gravity return oil flow. Do I really think that will happen? - Not at all, or I wouldna done it.
 My experience level with this sort of thing is minimal, I was just trying to follow the service bulletin recommendations.

BTW, I cut my own 5/8" holes in my HG to accept the 014 ring. Whats the OD of those tube orings (#3 your pic)? Whats the OD of the hole in the Athena HG?

[stlal]

I wont be back at my garage until next weekend but off the top of my head I would say the OD is roughly 1/2" on the seals and 5/8 on the HG

Im gonna go ahead and order some of those orings and roll with it.  I will keep you posted next weekend.

Seems to me the only thing running through there is the studs.  Maybe i;m wrong

Thanks again