Topic: no gasket!!!!

[possum2082]

check out this pic:

the oil pump/sending unit is covered by the same piece as the drive sprocket.  should there be a gasket anywhere?  mine didn't have one.  i've always assumed that if oil is contained somewhere, it needs a gasket.  also, notice the debris on the side of the oil pan.  is that coming from the oil or is that coming from a bad shifter seal?

sorry for all the questions.  per usual, thank you in advance.

[needswork]

Mine was the same, no gasket. ('78 550K).
In my case, the o-rings at the oil pump were  leaking (there's 3 of them I think). I replaced them with cheapie o-rings that fit (over a year ago) and haven't had a leak since. If you are doing that, good luck getting those bolts out  .

[kslrr]

There is no oil in any of these cavities under the left side cover.  there might have been a gasket to keep dirt out of the oil pump area, though my 350F never had one.  The oily dirt could be a leaking main shaft seal or shifter shaft seal though it looks like it is coming from the frount of the engine.  Clean the engine real good and then start monitoring leaks.

[possum2082]

thanks, guys.  i think i'm going to check out the o rings on the pump b/c of the oil in the compartment when i opened her up.

is replacing the shifter seal just pull the old one out and pop the new one in...?

[CBJoe]

My CB650 looked just like that and it was due to the Shifter seal.  You can pull it out with an angled dental pick or something like it.

Learn from my mistake.... when you put a new seal in DONT use a flat blade screwdriver.  It'll punch right through the seal.

Regards
Joe

[TwoTired]

thanks, guys.  i think i'm going to check out the o rings on the pump b/c of the oil in the compartment when i opened her up.

is replacing the shifter seal just pull the old one out and pop the new one in...?

Let me know if you can find a replacement oring for that pump. Pretty much unobtainium, and you can't put a larger cross section in there and keep the oil pressure up.  Gear pumps are side plate clearance critical.  Unless you know the oil pump seal is bad, don't mess with it.  If you damage the seal on disassembly, you're in for a long wait for a new seal to arrive.  And, operating with the wrong seal, you can shop for another engine.

Cheers,

[possum2082]

if the seal is not bad, how else would oil get in that compartment?

[kslrr]

The Oil Light switch might be leaking at the threads or internally.

[Kevin400F]

In this pic grabbed from the "mrcycles" online microfiche, you can see there are small O-rings on the supply and return ports, and a large one surrounding the gear, where the oil pump body registers to the crankcase.  Also one on the relief valve cap.  As mentioned above, the oil pressure sender unit is also a typical leak source.  There's an O-ring under the three-cornered cap which isn't shown .....I guess that's the one Lloyd was referring to as hard to get (I believe I have some, however). 

[seaweb11]

A lot of that poo looks like it came from the chain.

my 2cents

[florence]

I had this problem and I wrongly assumed it was coming from the oil seal around the gear shaft or the clutch pushrod (cb500), when in fact it was the oil pressure light switch at fault.  It got lots worse before I realised and worryingly it probably caused a drop in oil pressure.  The light switch fails internally, the oil seeps past the bakelite part above the nut and cannot be repaired.  Replace oil pressure switch unit as a whole.

[bryanj]

I Have the oil pump cover "O" rings and they are not now nor never were supplied by Honda---you have to buy a pump to get one

[Somemonkey]

I'm actually having the same problem. Though I suspect my oil leak is coming from the shifter seal, I'm going to take a look at the oil pressure switch to be sure.

[754]

Are you guys all blind!!

Even if there was a gasket, unless there was a rubber plug up top where the relief is for the sending unit wire..... stuff is going to be able to get in there..

 Is there a rubber plug on the wiring??.....

[mark]

 "Is there a rubber plug on the wiring??....."



I think it's that funny looking black thing right above the oil light switch in the photo. Speaking of the oil light switch... If there was oil sloshing around in there with the pump, it probably came from a bad switch.

my 2 cents. carry on.


Happy trails.



{btw... Does that rare pump cover o-ring come with a Genuine Honda lower gasket set?}

[754]

I yam looking at the cutaway above the sending in it where the sending unit wires exit from that cavity...


..continue on with the cavity searching...lol..

[mark]

Dang.... Are we lookin' at the same pitcher here...........

If the plug was gone, the oil pump cavity would be full of the same gunk that is around the sprocket/shifter.

right?

[754]

 

Ahh now I finally see the rubber plug in place.. looked like it was nothing there to me  the first 2 times I looked.

However.. if anything was on the mating surface during assembly.. like an oily piece of sand or grit, then it would allow chaindreck to get in there..

[edbikerii]

Over the life of my 77 CB550K (exactly the same), I've had a few leaks in that area:

First, the shifter shaft seal went.  Easy to replace.  Pushed the new one in with a properly matching socket.

Second, one of the three oil pump o-rings that go between the oil pump and the engine case went.  I just ordered the three new o-rings from Honda, easy fix.

Third, the oil pump cover o-ring went.  This is the top plate that is held on by the three phillips-head screws.  This o-ring cannot be ordered from Honda.  I hunted down a matching o-ring in my local auto-parts store.  I don't recall the measurements, but it seemed like a good fit.  I can easily see how having the wrong size (cross-section) could cause problems with oil pressure here.  I guess I just got lucky by finding a sufficiently close o-ring.  On the other hand, this might explain why I always need to use 20W-50 oil to prevent my oil pressure light from coming on.  This has worked fine for well over 10,000 miles with no blown up engine or oil leaks.  I'm just way too cheap to pay $200 for a new oil pump when the problem is just a simple o-ring.  Does anybody know the correct size o-ring and possibly a good source for same?  Maybe I'll change it out just to be sure, then I'll try the Rotella-T 15w-40 again!

Fourth, using an o-ring chain on the CB550, the wider o-ring chain eventually ate through the rubber plug next to the chain (with no warning whatsoever).  The recommended procedure for replacement is to split the cases.  Since I actually wanted to ride instead of wrenching, I used a product called "The Right Stuff" to seal that tiny leak up.  It has held for a few thousand miles, so I think I'm OK.

[paulages]

thanks, guys.  i think i'm going to check out the o rings on the pump b/c of the oil in the compartment when i opened her up.

is replacing the shifter seal just pull the old one out and pop the new one in...?

Let me know if you can find a replacement oring for that pump. Pretty much unobtainium, and you can't put a larger cross section in there and keep the oil pressure up.  Gear pumps are side plate clearance critical.  Unless you know the oil pump seal is bad, don't mess with it.  If you damage the seal on disassembly, you're in for a long wait for a new seal to arrive.  And, operating with the wrong seal, you can shop for another engine.

Cheers,

i pulled up the proper size on the honda fiche and bought a few at a local oil seal and o-ring supplier. there was a $10 minimum, and the o-ring was about $.20, so i bought a handful of them, along with enough o-rings to rebuild about 30 sets of cb550 carbs.

[TwoTired]

The Honda Fiche that I have does not have information about the pump cover gasket.  I would like to know what the original I.D., cross section, and/or O.D. for that pump cover seal is.
BryanJ,  did you find some that worked?  Or, did you have privy info as to original design parameters?  I'm uncomfortable measuring one that has been heated and compressed for 30 years.  And, as I don't have any that are leaking at this time, I don't want to break the seal in the hopes it will reseal upon reassembly.

Cheers,

[paulages]

The Honda Fiche that I have does not have information about the pump cover gasket.  I would like to know what the original I.D., cross section, and/or O.D. for that pump cover seal is.
BryanJ,  did you find some that worked?  Or, did you have privy info as to original design parameters?  I'm uncomfortable measuring one that has been heated and compressed for 30 years.  And, as I don't have any that are leaking at this time, I don't want to break the seal in the hopes it will reseal upon reassembly.

Cheers,

TT- i can't remember exactly where i got it, but i found measurements of all the o-rings, carb included. i'll see if can track it down.

[paulages]

here ya go:

http://www.crotchrocket.com/fiche_section_detail.asp

[Kevin400F]

Lloyd, the cover O-ring is 46mm ID x 2mm cross section.  See attached pic. 

[paulages]

ok...just noticed that we were talking about the cover specifically, which is not listed in the fiche. oops. i could have sworn i found a measurement somewhere. maybe in a parts book? in any case, the ones i got worked fine, if they weren't the exact correct size.