Topic: My pucks are leaking after 49 years... thanks Honda !

[Spanner 1]

So, the very worst thing that is wrong with my 49 yr. old K0/1 is that the 'pucks' have started to leak round about year 48 ! Motor never 'opened' yet. Runs like a champ with 38K miles. I'm not taking the head off , feck it I'll just pressure wash the ( so far minimal ) oil wash on the fins now and again

[TwoTired]

You know, auto trans fluid is supposed to help keep seals soft and pliable.  Could try some of that as an additive to your oil.

Likewise are some additives in synthetic oil offerings.
Stated in another thread was an experience of switching to a synthetic (brand not stated) and the engine developed leaks, which later healed themselves and stopped leaking.  The theory was that the synthetic additives behaved like a penetrating oil past marginal hardened seals, then the rubber swelled and once again sealed as it should. If I recall correctly, it was those pucks that were the leak/stop leak subject.

FYI.  Good luck.  It didn't help my oil passage orings in the head on my 550s.   Dang.  But, I only use semi-synthetic oil.  And, probably not the same blend as was in that posting.  I live with the weeping, as it is not that bad.

Cheers,

[evinrude7]

So, the very worst thing that is wrong with my 49 yr. old K0/1 is that the 'pucks' have started to leak round about year 48 ! Motor never 'opened' yet. Runs like a champ with 38K miles. I'm not taking the head off , feck it I'll just pressure wash the ( so far minimal ) oil wash on the fins now and again

the leaking gets worse ray.  just changed mine.  not too much trouble. 

[Don R]

Castrol high mileage oil, seals it right up! L0L!

[uksparky]

Go to parts store and get a bottle of Bars rear main stop leak...... add 6oz     used that on my oil pump seals stopped the small leak, i know its a temp thing until i get the courage to remove the mounting screws lol

[SohcCBs]

I pressed some rope in between the fins where that leak comes from.  It helped while out on trips.  Then clean or change the rope when needed.

Kept the engine cleaner.

[Tracksnblades1]

Castrol high mileage oil, seals it right up! L0L!

+1 on Max Life oils.
I don't like putting anything in engine oil that has diethylene glycol monoethyl ether or variants.
Jet fuel icing inhibitors, ink, paint, solvents.....and an active ingredient in dot3 brake fluid....
No thanks.

[Spanner 1]

Thanks for the advice fellas.

[Don R]

 Ethel has mono?

[Tracksnblades1]

Ethel has mono?

Oh no....I hope not...😎
My pucks were leaking yesterday. Terrace riser was plugged up. Had a little skinny 400ft pond.
I was wading around with shovel in mud. Both my pucks were leaking and too soon to be dragging...
😩

[Deltarider]

Castrol high mileage oil, seals it right up! L0L!

Lucky you. Not in my experience however. Although I saw improvements with other seals and hope it does something good for the valve stem seals, as long as I've owned my bike (since 1980) it has always sweated some at the head, even after a professional top rebuilt. It's just a minor sweating not even threatening my pants. Less when I ride it daily. I can live with it.

[PeWe]

Virgin engine....
I guess there are some to fix  if it has been used some during the decades.
Leaking oil is the engines cry for " please restore me" !

[Johnie]

I do the same thing as SohcCB's above. I got this trick from this forum years ago. I take 1/4 inch cotton rope and stuff it between the fins in front of the seal. Works like a charm. Keeps the motor clean. I can go over a year before I have to change it.

[SohcCBs]

I do the same thing as SohcCB's above. I got this trick from this forum years ago. I take 1/4 inch nylon rope and stuff it between the fins in front of the seal. Works like a charm. Keeps the motor clean. I can go over a year before I have to change it.

I used cotton rope, thinking nylon might melt....but I guess it didn't.  It does work pretty well....keeps the engine clean.

[lrutt]

I do the same thing as SohcCB's above. I got this trick from this forum years ago. I take 1/4 inch nylon rope and stuff it between the fins in front of the seal. Works like a charm. Keeps the motor clean. I can go over a year before I have to change it.

Use Cotton rope. Got mine at Ace. I've had it in my K8 for several years now. Once tucked way in there you never see it unless you're really looking for it.

[Honda3]

So, the very worst thing that is wrong with my 49 yr. old K0/1 is that the 'pucks' have started to leak round about year 48 ! Motor never 'opened' yet. Runs like a champ with 38K miles. I'm not taking the head off , feck it I'll just pressure wash the ( so far minimal ) oil wash on the fins now and again

My 1973 CB500F started doing the same a few weeks ago. I cut up an old t-shirt and rolled little pieces of it like a pencil-long joint, or doobie depending on which generation youre from. Stuffed it in between the fins and I cant see the leak anymore. Out of sight, out of mind.

[The Lone Builder]

I always say, it’s better to appear stoopid for a moment than remain ignorant for a lifetime.

What are pucks?

Sean

[PeWe]

Warm oil leak smells bad. It is worth the efforts to avoid that. Just cleaned engine, warm degreaser smells nice!

[70CB750]

I always say, it’s better to appear stoopid for a moment than remain ignorant for a lifetime.

What are pucks?

Sean

Rubber seals under cam shaft towers in CB750 SOHC4 engine.  Lot of threats on the topic, the must read is here:

http://forums.sohc4.net/index.php?topic=107040.0

Also not all pucks are created equal - some are too thin to seal properly.    More info in Hondamans book.

[bryanj]

Also between cam cover and head on 500/550, they are used to seal the holes thar are there for access to head nuts. In UK also know as Pontefract cakes

[Honda3]

Also between cam cover and head on 500/550, they are used to seal the holes thar are there for access to head nuts. In UK also know as Pontefract cakes

my 73 CB 500F is leaking. Its a gorgeous bike and this sucks!

[DaveBarbier]

Also between cam cover and head on 500/550, they are used to seal the holes thar are there for access to head nuts. In UK also know as Pontefract cakes

my 73 CB 500F is leaking. Its a gorgeous bike and this sucks!

Can be fixed in a couple hours. Why live with the leaks?

[Honda3]

Also between cam cover and head on 500/550, they are used to seal the holes thar are there for access to head nuts. In UK also know as Pontefract cakes

my 73 CB 500F is leaking. Its a gorgeous bike and this sucks!

Can be fixed in a couple hours. Why live with the leaks?

I was told by a mechanic that the top end has to come off and it would cost around $1,500 as the head gasket needs to be replaced too, etc etc.

[bryanj]

No need to remove head to do the pucks but a common leak is the oil feed O rings in the head gasket which does need the head off, 3 hour job if you dont touch the valves or cylinders---not always a good idea on an old bike.
Another leak is possible from the bolts that hold the steel brackets the cam end caps fasten onto worth checking there as well.

[Honda3]

No need to remove head to do the pucks but a common leak is the oil feed O rings in the head gasket which does need the head off, 3 hour job if you dont touch the valves or cylinders---not always a good idea on an old bike.
Another leak is possible from the bolts that hold the steel brackets the cam end caps fasten onto worth checking there as well.

Yeah I think mine is the O rings