Topic: 1977 cb550k oil leak

[Bvivas]

I bought a cb550k in 2019, After finishing this project the bike was in storage until march 2023. I recently started driving it. A few months I noticed a leak on the left side of the engine. When I took the left side cover I discovered the leak was coming from the oil pump. I bought a rebuilt kit and I though the issue was fixed. I drove the bike and noticed the issue was not resolved. I removed the cover and saw that the oil pump was dry but there was oil coming from the shift shifter shaft. I bought a new seal and I thought I resolved the issue ( I reinstall the left side cover and drove the bike for a few days) but I still see oil dripping from the left side. I removed the cover for the ten thousand times and cleaned the section where the oil pump is, the shift shifter shaft, and a section of the engine. I left it alone for a few days( i did not drive it), I went to check and there was no oil leak. so I drove it for a few minutes around the block. When I removed the cover I did not see any oil leaks. It only happens after a long drive. if I don't remove the cover I see the oil dripping from a bolt on the bottom section of the engine ( is not the oil drain bolt) I'm attaching pictures, if anyone has an idea of where the oil leak is coming from or what can I do to detected it,  please let me know.

Thank you
Byron

[newday777]

As this is your 1st post on the forum welcome aboard!

I was noticing your chain, is it an O-ring chain?
If so, remove the chain and front sprocket and inspect the case behind there for grinds in the case and seal. Someone posted the other day either here in the forum or on fb in the 500/550/650 group of their bike leaking because of the seal on the output shaft had a hole in the rubber from the extra width of the O-ring chain.

[bryanj]

Any oil will always leak /drip from that bolt as its the lowest point, could be comming from anywhere
When you rebuilt the pump did you change the 46x2 O ring under the cover?

[dave500]

as newday said have a look here,this one aint bad,they can be worse,dont use an oring chain on 500/550s,some are wider and really damage the case.

[Deltarider]

To diagnose, first clean that area well and then blow some talcum powder on it. The oil will leave a trace. On CB500/550s it is usually from the shifter shaft seal. It can be replaced easily. Do a search here. Lots of reports and tips how to do it. I had bought a new one, but it's still in its package. Since I began using Castrol GTX 15W-40 High Mileage, the issue has cured itself.

[newday777]

An enlargement of Dave's picture shows the plug damage starting. Looks like he used a torch lighter to point to the damage.

[CycleRanger]

Howdy! Welcome!

As the other guys mentioned remove the chain and sprocket and inspect this area.
From your photo I can see where the chain has been rubbing.

[Bvivas]

Thanks everyone for the response

Monday is my day off and if it does not rain I'll work on the bike.

@ newday77.

 I don’t remember the type of chain it was installed
I'll take the chain and sprocket out clean the area inspect for damages on the seals

@ Bryan j.

I think so this is the kit I used. I wanted original and this is the only I was able to find at that time. I actually saw it in a forum ( I don’t remember which one)

 https://www.ebay.com/itm/224064376252?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=_p-q3hvvQhS&sssrc=4429486&ssuid=wWsRLQhJTCq&var=&widget_ver=artemis&media=SMS

@delta rider

I replaced that o ring.  But I will used your advice to use the power to see traces of the oil
 I was thinking of using leak detection dye but I'm afraid of destroying the engine

I'm going order a whole kit from 4into1, Just in case

https://4into1.com/engine-oil-seal-kit-honda-cb550/



Do you guys recommend anything in particular to clean that area?  I used brake cleaners and simple green?  But I'm afraid that might damage the seal.

Thanks for all the help

[bryanj]

Thats the one, you wont find a "correct" one as it was never listed as a spare, you had to buy the pump.
I took a long time many years ago working out what size would work

[dave500]

An enlargement of Dave's picture shows the plug damage starting. Looks like he used a torch lighter to point to the damage.

aint no torch lighter,its the back end of a telescoping magnet!

[Bvivas]

@Newday777

You were right. The o ring is damage. The new chain damage the o ring.
Any recommendations to which chain to get now?

[newday777]

@Newday777

You were right. The o ring is damage. The new chain damage the o ring.
Any recommendations to which chain to get now?

Clean up that area well and retake the picture

[Deltarider]

@Newday777

You were right. The o ring is damage. The new chain damage the o ring.
Any recommendations to which chain to get now?

But... the question remains: does it leak oil there or elsewhere?

[CycleRanger]

Looks like the seal for the neutral switch may be leaking as well.
Wouldn't hurt to replace that one while you're there.
Actually, probably a good idea to change out all the seals.
Yes, clean it up so you see everything clearly.

[bryanj]

Thats not an O ring

[denward17]

What is that above and towards the center, neutral switch?
It's hiding behind the wires in the pic.

[bryanj]

Its the rotor for the neutral switch, screwed to an extension on the selector drum that has  a seal around it

[Bvivas]

I’m sorry it took me a while to respond


Here are the pictures after I cleaned the area.

[Bvivas]

I drove for a while after cleaning the area and I found oil below the area of the o ring that the chain has been rubbing. Also by the shifter o ring. Not sure if the oil on the shifter is just the accumulation of it when I dripping or is actually Coming out from there. 

I also notice oil on the left side cover on the section where the oil pump is. I inspected the oil pump and I don’t see any oil coming from there. I used  a white paper towel to clean it and I did not see any oil in the paper towel. I also noticed oil on the back plastic fitting that is above  the oil pump. I used a white paper towel to clean it, I  followed the cables that were coming out of the left side cover and they have oil. Paper towel was dripping oil.  ( I use a small paper
Towel

I think the wind or the chain moving at high speeds is pushing the oil that drips to that area to the black Pasting fitting  is and from there is dripping to the cables ? ( black plastic fitting above the oil pump)

I think just to be on the safe side. I will replace both o rings. The one that the chain is rubbing and the one on the shifter. 

I also was thinking of driving the bike with of the cover and attach a GoPro camera to see where the leak is. But it looks dangerous. So not sure.

If anyone has a better idea. Please let me know
I was also looking for instructions or videos on how to replace the o ring that the next to the chain. But I can’t find anything. All I’m able to find is how to replace the o ring that is in the shifter.   

I’m also thinking to keep the same chain and maybe get a spacer to offset the gap. But not sure if that will be safe I don’t want to damage the o ring behind the sprocket ⚙️

When I was searching I was able to find this

https://cognitomoto.com/products/17-tooth-3-8-9-5mm-offset-sprocket-for-cb750-cb550-cb500t?variant=606557365

Is says sold out.  It not user if someone here have used it.

[calj737]

I’m also thinking to keep the same chain and maybe get a spacer to offset the gap. But not sure if that will be safe I don’t want to damage the o ring behind the sprocket ⚙️

If you offset the front sprocket, you need to offset the rear sprocket equally else the chain will not be running in a straight line (which will cause all kinds of other issues). Best to resolve the oil leak and leave the sprockets as they are.

[Killer Canary]

The oil pressure switch can also develop a serious leak where the terminal is screwed on.
That one threw me for a while.

[CycleRanger]

Get a seal kit and replace all the seals. 

[Deltarider]

Have I missed it? I haven't seen/read yet where exactly the leakage is. Also... how serious is it?
My shifter shaft seal has leaked for quite some years, but it was acceptable imo and I have lived with it.
I have a new one (PN: 91202-216-000), but it's still in its plastic bag. The old one cured itself, after I switched to another oil more friendly to rubber parts. Same happened to the oil pan packing btw.
I only do maintenance/repair when it's needed and I certainly will not replace parts unless a proper diagnosis tells me it's needed.

[dave500]

deltas bike still has the japanese air in the tyres from the factory.

[bryanj]

THEY AINT O RINGS

[Bvivas]

@ delta rider

I think it’s bad. I thought it was a little bit but I drove yesterday and   I noticed my left shoe was full of oil marks. The left peg had oil, the shifter had oil, the left side of the frame had oil, and the bottom section of the engine ( oil pan). I drove for almost 2 hours. I just can tell where is coming from.  And I would like to replace the seal that’s next to the sprocket.  I was able to find a chat that said the case needs to be opened to replace that seal.  But there was one person that said that it can b replaced but I need to drill a hole in the center of the seal and then use a screw and other tools to remove it.  I’m not sure what to do. I just bought a non-o ring  chain. If I can’t find a proper way to remove that seal I will use some honda bond on the section that the chain was rubbing.

Any suggestions?


@ Bryanj
Now I know the correct name is seal

[calj737]

If you’re leaking that much oil, stop riding the bike. It’s dangerous (oil on rear tire) plus you may be operating the bike with too little oil.

Removing that seal without splitting the cases can work but it’s a low margin of success because installing the seal behind the lip requires crushing the seal and hoping it expands back to proper diameter without incurring any damage is unlikely. Most who have attempted this end up with more oil leaking there than before. (If that is the source of the leak which is still unknown).

[bryanj]

Whilst people have said its possible, i have been working on 500 and 550 since they were new and i dont think so, its an incredible bodge

[Deltarider]

Any suggestions?

Ok, I understand the leakage is serious. First a remark. Check you haven't overfilled with oil. Level should not be higher than the upper mark. Actually quite a few CB550 owners have made it a habit to have the oil level halfway the marks to prevent problems with the blow-by gas fouling the airfilter element. But in your case I doubt it will be a remedy for your problem.
This is what I'd do. Run the bike till it is hot. When returned home, put bike on the main stand and select first gear. Kill engine. Remove the cover and clean the area. Then restart the engine with clutch engaged. Release clutch, kneel down and look closely where it leaks. Idle and rev a bit if necessary.
Personally I hate to undertake any action, unless I have a good diagnosis.
When you're 100% sure that difficult seal is the problem, I'd bring it to a professional workshop who can do it. In Holland we have quite a few who can do the repair and then it's their responsibility.
Unless others here can guide you how to do it yourself.
 

[dave500]

ok Bvivas,ill book your flight to Holland,your staying at Deltas place.

[calj737]

ok Bvivas,ill book your flight to Holland,your staying at Deltas place.

Don’t forget the shipping for his bike, Dave  Should only a few thousand PLUS the labor of a shop.