Head gasket oil leak.

sixinoz · Post by **sixinoz** » Tue Jul 17, 2018 5:42 am

Oil leaking from LH side of head gasket so it looks like a new gasket. The questions I have are:
1. Can the head be removed by only removing the one camshaft and the chain to the crank?
2. I read on the forum that some people use copper gaskets. Which are best copper or fibre and which brand? I can get Athena and Forsetti in Oz but not sure of the quality?
3. Cam cap bolts seem to be a problem on reuse (snapping off). CMS want the equivalent of US$9 each with shipping to me!!!
I see non oem are available. So should I replace all or just from the cam I take off?
Valves were done about 6,000 kms ago so I'm hoping they just need clearances checked/ adjusted.
Thanks for any extra advice you can give me.

daves79x · Post by **daves79x** » Tue Jul 17, 2018 8:16 am

It is highly unlikely it is your head gasket. They almost never leak. Much more common is oil leaking past the copper sealing washers on the head bolts (under the valve cover gasket). Oil then runs down the stud and down the head/block fins. You need to clean everything up completely and see where it is actually leaking from. If you find one leaking and it won't fully torque, then that stud is pulling out of the block, which is not uncommon. Porous castings cause that. Head at least has to come off to fix that

And if you haven't done this a hundred times, do not take shortcuts. Follow the shop manual exactly and if you don't have one, don't touch it until you get one.

Dave

EMS · Post by **EMS** » Tue Jul 17, 2018 3:46 pm

Once you get into it, spray a regular head gasket with copper spray, which will improve sealing, no need for a copper head gasket.
Better cam cap bolts are available. A member here from California sells them. Do a search. He can be reached at genesound@usa.net. He is a great guy to deal with. He also sells viton valve shaft seals, which may be a good thing to replace, once you have the head off.

sixinoz · Post by **sixinoz** » Tue Jul 17, 2018 5:52 pm

Thanks for the tip, Dave. I sure hope I find that it is just a head bolt seal and that a washer and retorque will cure it.( Too much to hope for?)
My bike is a May 78 build but it has the spiral studs so I'm hoping that they will be ok.
EMS thanks for the gasket tip.
Will report back when I find the source of the leak.

sixinoz · Post by **sixinoz** » Wed Jul 18, 2018 1:46 am

Checked all studs on that side - all dry. Put tissue paper around gasket edge and it is coming from the LH outermost area - just above the single head bolt. So now I ask would it be any good in checking the torque of the 2 outer most head nuts and the single outer bolt or does this problem indicate just a gasket failure or could it be pulled studs?
Never had a single drop of oil leaking until a ride last Sunday of about 60Km. Warmed up the engine and never exceeded 5000rpm the whole trip - so pretty gentle.
Seems like for every hour you ride a CBX you spend 4 hours on repairs and maintenance!

daves79x · Post by **daves79x** » Wed Jul 18, 2018 7:24 am

Are you positive it's not coming from more upward and rearward, maybe the cam cover end gasket? A leak where you describe is very rare. Has this engine been apart? If it is indeed at the gasket, you can certainly try checking head bolt torque.

Once a CBX is well-sorted, they are extremely trouble free and reliable. The key is well-sorted. So many of these have been so abused over the years and worked on by hack owners/mechanics that it often takes a lot of work to get there.

Dave

Larry Zimmer · Post by **Larry Zimmer** » Wed Jul 18, 2018 11:23 am

A side note on the cam cap bolts: You might find a 6mm at some local hardware outlet that can work. Do be certain that it is a grade 10.9 though. (Or higher.) Ordinary grade will note handle the torque. If not a flange head, use a washer under the head to prevent gouging the cam cap. Length accordingly.

sixinoz · Post by **sixinoz** » Thu Jul 19, 2018 11:13 pm

Checked this out thoroughly - definitely coming from the head gasket. Mainly from areas shown by the arrows in the photo.

Checked the outside bolt - up to spec but I did not back it off to do this. I have not taken the cover off to check the head nuts.
The PO said the head had been off 6,000 km ago to do valves and hone with new rings. It was apparently done by a racing engine builder of good repute so I assume he checked the head for warping.
Very disappointing to say the least as I will have to take the head off to check if bore is still standard before I order a gasket plus delivery time to Oz = weeks off the road. Thought I might do the base gasket as well but I don't have a ring compressor - yet!
Anyway I might just ride it for a while and put up with the leak until I bite the bullet.
As per the original post can I get away with just removing the one cam to get the head off??
Thanks for the replies - and if anyone has a "snake oil" fix let me know!

daves79x · Post by **daves79x** » Fri Jul 20, 2018 8:00 am

So the head had been off. Someone didn't get something right - they don't just leak. Either the gasket surface is compromised there or the gasket itself is faulty. All these heads are 'warped' a bit. Head gaskets still seal. Just pull the head per the manual - yes, remove all the cams. Inspect carefully that area and you'll likely see what's wrong. If a new gasket is all that's required, you'll be back up and running in a day. Why do you fear pulling all the cams?

Dave

EMS · Post by **EMS** » Fri Jul 20, 2018 8:03 am

I have never done it, but I guess you can remove the head with the intake cam left in place.
As far as ring compressor(s) are concerned, you will need 4 of them.
There is a seller on ebay US, who still sells them.

sixinoz · Post by **sixinoz** » Sat Jul 21, 2018 1:14 am

Ok - thanks for the replies.
Another thread on head gaskets had Ridgecrest Engineering in Australia as a maker of copper gaskets.
Since they are in Australia I could get a gasket quickly.
The thickness can be .7mm to 2mm. Has anyone recently used one and of what thickness? Is it better to stick to fibre as Honda did?

SteveG · Post by **SteveG** » Sat Jul 21, 2018 7:12 am

I would not want to leave a cam installed in the head and then remove the head. Some of the valves will be open and ripe for damage.

Steve

sixinoz · Post by **sixinoz** » Sat Jul 21, 2018 5:28 pm

Good point Steve. Thanks for the tip.

sixinoz · Post by **sixinoz** » Sun Aug 05, 2018 3:03 am

Further to this discussion I have located the main source of the oil leak. It is directly in front of the rear stud (see photo). There is no oil running down the stud but only coming from the gasket where the stud is.
Any ideas on why this would be? - obviously not coming from head nut and washer, but is there any oil pressurised gallery near there?

rsuarez · Post by **rsuarez** » Mon Aug 20, 2018 7:24 pm

A little bit to the left from the arrow you have the oil passage to the head. I bet thats your problem.

The International CBX Owners Association

Head gasket oil leak.

Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.

Re: Head gasket oil leak.