Topic: cb500 oil pump O-ring

[turboguzzi]

Good morning

My CB500 has a tiny leak from the outer cover of the oil pump. took the three philips screws that hold the external cover out and indeed, the very thin O-ring is somewhat dry. Just to clarify, I am NOT talking about the O-ring between the oil pump body and crankcases but rather the one that seals the pump rotor cover.

Checked out the parts list and turns out that honda doesnt list that O-ring at all! Only the whole oil pump as a single assembly!

Does anybody know if there's a separate part number for this O-ring?

Cheers & thanks
TG

[bwaller]

Well you're right - no P/N (sorry but I doublechecked a couple microfische) and that's a bit of a surprise. That must have been included in the o-ring kit in an early gasket set, but I can't remember for sure. If you can't find the exact size, I've had good luck making o-rings from those "do it yourself" kits.

By the way, what was the total weight for your roadracer and how is that going?

[clarkjh]

Turbo

I cut out a thin fiber (bulk gasket) ring to back against the rubber O-ring, no more leak on my 550.

James

[csendker]

Someone on here sells them...do a search and he'll pop up.

Found it:
brianj sell 'em --> http://www.sohc4.us/forums/index.php?topic=14863.msg148841#msg148841

[turboguzzi]

thanks for the tips. still, kind of crazy that this o-ring isn't listed.....

a bit apprehensive about adding an extra ring as in order to maintain the right clearance between cover and rotor the cover needs to bottom on the pump body lip. looks like I'll contact brianj soon.

bwaller, haven't gotten around to weighting the bike yet. since I don't have much weight watching issues I don't have a scale at home :-) will do though

next race is 15 of july, made a few upgrades in the meantime like fitting thin suzuki discs, adding an interesting head steady to the frame and mounting a really neat Menani 70's seat.

Will post some updated pics soon

Cheers
Yossef

[peter c]

Hi yossef, been offline for a few weeks and just caught up a little on your progress. Not raced either of my bikes yet,750 not yet ready and have let a young guy use the 500 for a championship. will be racing both at Chimay end of july. Looks like you'r making progress,what problems?

Peter c

[turboguzzi]

Hi pete

long time no see!

not much problems other than that little leak. tried today to close it with a little sealer on the mating surface and so far so good.

In any case, david silver resonded to me today and indeed, they dont have that damn O-ring. any ideas?

I looked in the Chimay race site and it looks tempting, thing is that i'll need to take some days off work to get there, not sure I can, so let's see. Some people from my club are going to be next month in the classic endurance race at Spa with some CB500's. Too many events, not enough time and budget!

cheers
TG

[Master Ted]

PM Bryanj... he helped me out last winter with same problamo.

[edbikerii]

Several years ago, I took that old dried o-ring to my local "united auto parts" store, and matched it up pretty closely to another o-ring in their o-ring assortment box.  It hasn't leaked since.

[peter c]

Yossef,
I had the same problem with my 500. I would so love to do the Spa endurance,maybe next season we can get enough cash to have a go. Chimay is a great classic event but it takes us 6 days to compete.Did you get a close gearbox yet? My contact is back in prodution with his conversion at about 600 euros plus shipping.

Peter

[bryanj]

I am now back on line after a house move---just the putting away to do, still got a few years to do that.
Yes I do still have "O" ring sets comprising of 1 x cover; 1 x body to crankcase; 2 x oil feed/suction. All I have to do is find them!

With the £ $ exchange and paypal taking a cut its $10 airmail to the US.PM me or mail bllj@blj.org.uk if you want them

[turboguzzi]

Thanks Bryanj

Will contact you soon.

Cheers
TG

[ckiernan]

I just had the orings in my '78 cb550k start leaking the larg o-ring is 47mm and I found that my local NAPA parts store has a great selection of metric o-rings for sale individually for 50 cents appeace.

If you can't find one locally let me know and I'll mail on to you.

[Noco]

I am now back on line after a house move---just the putting away to do, still got a few years to do that.
Yes I do still have "O" ring sets comprising of 1 x cover; 1 x body to crankcase; 2 x oil feed/suction. All I have to do is find them!

With the £ $ exchange and paypal taking a cut its $10 airmail to the US.PM me or mail bllj@blj.org.uk if you want them

I am working on a '72 500 that has this problem,
Do you have any o-ring kits still available?
I tried the above email address, but it bounced back.
cheers,
noco

[bwaller]

Noco send Bryan a PM, he still had some available a while back.

[bryanj]

Still got them, if it bounced its usually cos your server dont like the .org They think i'm a business but i aint---it was they only available domain when i wanted one years back.
Try again or use the pm facility.
Still at $10 one set $15 two due to paypals cut and airmail cost.

PS can't remember the size it was but it took me about 2 hours of work at a really big hydraulic supplier to get the ones i have cross referenced as the cross section is a very unusual one