Oil Leak NGC

[Kiwi_Roy]

I have a lady friend with an early 80s Honda Nighthawk 450.

She recently had the oil changed, I think they installed semi-synthetic

It's started to leak oil from both of the "O" rings of the oil cooler. Honda say the "O" rings are not available any more. I tried installing new seals from a commonly available kit but the imperial "O" rings are quite a tight fit in the casting, not loose like the Japanese originals, it's still leaking from one seal more so at night while parked.
I seem to recall from somewhere you shouldn't put synthetic in an older engine.
Is that so?
Where do we go from here, I assume it will be hard to get rid of all the synthetic oil.

Thanks
Roy

[Moto]

I'd think the concentration of synthetic with the conventioinal oil would be the issue, not its absolute absence. How about two quick oil changes w/ a cheap conventional oil, run up to temperature, and then a final change with a new oil filter, using the desired long-term conventional oil? The oil is cheap enough.

Moto

[RinkRat II]

  Find a good hydraulic shop and get the right o-rings.That bike is is new enough as to not have the synthetic affect the elastomers. My$.02

       Paul B

[cloudbase]

You ought to be able to find a metric o-ring kit without too much trouble.

[RinkRat II]

         I believe that is a CB 450 and if memory serves, does that oil cooler have purpose built o-ring gaskets on the end cover and whereit bolts to the block?
    If so, those are still available and You might want to try a different Honda dealer. Or Babbits on the interweb.

          Paul B

[Kiwi_Roy]

         I believe that is a CB 450 and if memory serves, does that oil cooler have purpose built o-ring gaskets on the end cover and whereit bolts to the block?
    If so, those are still available and You might want to try a different Honda dealer. Or Babbits on the interweb.

          Paul B

Yes it does like a figure 8 or more like two Ds back to back on the inlet outlet strangely we were able to get this one to re-seal it's the oval one on the end cap causing most grief, I figured a normal round one would be ok there, I had one just a tad short but the cross section barely fits in the groove.
She told me the Honda dealer tried all over BC for OEM seals. Thanks for the contact.

[analog kid]

number 4?

P/N 15911417000

shows as available on this NL website: https://www.cmsnl.com/honda-cb450sc-nighthawk-1982-c-usa_model456/partslist/E++10.html

I recently recommissioned my 81 Honda GL500 and had to replace a few seals. I'll try to remember which North American parts website I used.

Edit: David Silver Spares doesn't seem to have: 15911-417-000    PACKING, OIL CAP     Qty 0    6.48$USD

[analog kid]

it's the oval one on the end cap causing most grief,
She told me the Honda dealer tried all over BC for OEM seals.

I've heard that one before...

it might very well be NLA, but it might also be worth checking a different dealer.

A surprising number of parts are still available for the weird GL500 Twisted Twin. I'd bet the Nighthawk outsold the GL by a large margin.

Edit: just checked Babbits, PartsFish & Partzilla. Not available. Uh oh! maybe it is NLA 

[JayDee24ca]

Roy
Here is the part available in the Netherlands. https://www.cmsnl.com/products/packingoil-cap_15911417000/#.W3zvV-hKjIU
If it is available there, surely we should be able to find this side of the big puddle
John D

[Old Jock]

Roy

If you are struggling & that part in the Netherlands is what you need, I'll get them for you and post them on, if you have no luck.

Only thing is it might take a while to make its way across the pond

PM me

John

[Huzo]

Let's know if you are still in trouble when you run out of leads.
I have a friend in Tilburg in the Netherlands who is a biker also and he will pull a rabbit out of his hat for you.
I will hook you up with his e mail if you need it.
Huzo

[Kiwi_Roy]

Wow, great work guys, I will contact the owner again and see if she had any luck at the local industrial supplier.

I have purchased other parts from Netherlands, they came pretty quickly.