What do I need to fix my oil leaks?

[Drew400]

Hello all,

When I rebuilt my 400/4 some years ago, I didn't quite seal it properly so I have oil weeps from most of the major split points (i.e. cylinder head, block base, etc.). They're not bad enough to worry much about, I just wipe it over every time I use it... it's hardly old British bike territory!

However (you know what's coming), this enforced isolation business is a good opportunity to spend time in the garage fixing it.

My question is this:

I would like to buy all the bits I need to do the job IN ONE HIT (especially as some of it will come from David Silver and so I'd just like to pay one lot of postage please)! Is there anything else I need on my shopping list in addition to these items:

- Gasket set
- Oil seals set
- Head bolts (with oil seal washers)
- Hylomar or some such

Thank you, D.

[Nurse Julie]

Ditch the Hylomar from the list Drew. Its only the crank cases that need sticking together with the lightest, lightest smear of Honda Bond as they are machined surfaces and have no gasket. Other than than that the gaskets do the job everywhere else.

[Drew400]

Thank you Nurse Julie. Maybe using that stuff last time is my problem... not that I can remember what I did/didn't use!

[Nurse Julie]

Out of interest Drew, why are you going to use new head bolts?

[Drew400]

Can't remember that either, but I  know they leak all from the top if the wrong ones are used, so I guessed they can't be re-used.

No doubt when I actually start the work, some of this will come flooding back!

[Nurse Julie]

Can't remember that either, but I  know they leak all from the top if the wrong ones are used, so I guessed they can't be re-used.

No doubt when I actually start the work, some of this will come flooding back!

They can be re used with no problems at all Drew. No point in spending money on something that is not needed. When you are stripping the engine you just need to have a close look at what you did before that has caused the engine to leak.

[bobv7]

To keep an awkward gasket in place I find a light smear of high temp grease helps.

[Nurse Julie]

To keep an awkward gasket in place I find a light smear of high temp grease helps.

Me too Bob 👍👍👍

[matthewmosse]

Did you re torque all  the head bolts after a few miles riding? ( then check tappets ) been a long time since I did anything on an sohc engine so I am really rusty, might be worth trying. I have cured the odd leak with things like that - just not sure it's the totally correct fix.

[Bryanj]

Head is studs not bolts, some of the nuts have special "copperised" washers to seal oil and they ometimes need replacement but are dear.
Hondaman on the US site has worked out that modern gaskets are thicker so you need thicker cross section O rings to seal properly. Could be worth going there and asking him for sizes.
Retorque was never done in dealerships and if everything clean and flat shouldnt need it

[Drew400]

Thank you all for your wise council.

Bryanj - the copperised ones are the ones I was thinking of. I'll check out Hondaman too.

I think we can all agree, there's probably no rush to do this as I think we've all now got lots of spare time on our hands!

Stay well everyone.

[mike the bike]

You don't need new copper washers on the head studs. Heat them up to cherry red and quench them. This annealing process softens them so they seal better.
Hope it all goes well with the strip and you don't find anything narsty.

[Drew400]

Thanks Mike, will do. I'm hopeful it will still be like a clean sewing machine in there!

[Bryanj]

Unfortunately they are not solid copper but i think coppered steel

[Drew400]

Ah, thank you experts all. Cheer, D.