Author Topic: Oil Leak from the Head (Read 7450 times)

MikHalifax · « **on:** May 26, 2008, 08:03:19 PM »

Got a '73 CB500 w/ 22,000mi. My Dad bought it used in the 80's and I inherited it. Runs great but hasn't been very well maintained. Currently working on restoration. My question is, there is an oil leak coming from what I assume would be the head gasket area. I would like to replace the gasket but have been told that I would have to readjust all the carbs afterward. It runs so well right now that I'm wondering if this is true. I may have to put off this project until the winter if I have to readjust.

Any input would be greatly appreciated.

Thanks

bwaller · « **Reply #1 on:** May 26, 2008, 08:42:40 PM »

Welcome aboard.

No need to worry about disrupting the carbs, just remove them and reinstall afterwards. There is no voodoo involved anyway!

An oil leak between cylinder & head is usually because of two top-end oil supply o-rings sandwiched in the head gasket either end. They become hardened with time because of exposure to heat and oil.

It is necessary to replace both head and base gaskets as well as any rubber sealing parts. If you can, buy genuine Honda replacement parts, (a little more scratch but worth it.)The key is to clean all gasket surfaces very well without gouging the aluminum. It's not always needed but if you want to be sure have a reputable motorcycle engine shop just machine enough material from the head and cylinder gasket surfaces to be sure they're perfectly flat.

If it's a new experience, buy a Honda service manual. Plus there is always this place to get all the advice you'll ever need.

mattcb350f · « **Reply #2 on:** May 26, 2008, 08:46:39 PM »

You beat me to it Brent

I was gonna suggest take a pic of the area of concern and post it so we know for sure where the leak is.

Cheers, Matt.

MikHalifax · « **Reply #3 on:** May 26, 2008, 09:03:14 PM »

I'll get some pics tomorrow and post them. Thanks very much!

bryanj · « **Reply #4 on:** May 27, 2008, 01:34:20 AM »

Purchases required in importance order:-

Manual-preferably Honda
tools:-
3/8 drive metric socket set
Decent torque wrench
Impact screwdriver
Gasket scraper
Gasket set
Oil
Oil filter
Carb to head rubbers (NOT expensive and soft ones make a swine of a job easier!)
3 yards of patience
BEER---TO BE CONSUMED AFTER FINISHING

MikHalifax · « **Reply #5 on:** June 04, 2008, 06:15:24 PM »

Thanks for all the suggestions, here are the pics finally. Is that the standard oil weep I hear about? These pics show years of accumulation, but to give you an idea of speed of the leak. After each ride there are usually 2 to 3 drops of oil beneath my bike. I ride with chaps and it usually spits a little onto them during the ride. If I rode with shorts, I can feel a little hot oil on the calf once in a while. Ouch.

MikHalifax · « **Reply #6 on:** June 04, 2008, 06:17:25 PM »

A few more. It's ugly and needs a lot of TLC, but man does it fly.

WFO · « **Reply #7 on:** June 04, 2008, 06:45:04 PM »

Sweet starter button

is that OEM?

bryanj · « **Reply #8 on:** June 04, 2008, 07:31:30 PM »

Forget the leak till it gets worse

DONT WEAR SHORTS then it wont hurt

MikHalifax · « **Reply #9 on:** June 04, 2008, 08:23:28 PM »

Don't usually wear shorts, I almost always wear the chaps, laid down a bike once without them, won't do that again. But it would be nice for the 1 mile drive to work to not have to put them on for fear of ruining pants

Yeah that starter button was my dad's handy work. He can fix almost anything if it's broken, but if it's just a matter of motorcycle maintenance, well you can see the results...

mystic_1 · « **Reply #10 on:** June 04, 2008, 09:30:16 PM »

Quote from: MikHalifax on June 04, 2008, 06:17:25 PM

Woah, and I thought I was styling because when I got my 750 it included a bent paper-clip to use as a starter button! It was perfectly formed to clip onto the carb cable so it was very convenient for the first six months or so, but dayum, your rig makes mine looke downright shade-tree

I had to actually UNHOOK mine in order to use it. Sheesh!

Seriously though, yeah your head gasket is definitely leaking, time to swap it out soon. You can probably get away with a quick-and-dirty top end job if the bike is running that well. Go ahead and replace the cam tensioner gear since you're in there, it's a good investment.

mystic_1

brianzenk · « **Reply #11 on:** June 05, 2008, 09:33:23 AM »

Be sure to check the oil seal on the
tach where it hooks into the engine and
make sure it is not the problem. I ordered new
oil seals from the honda dealer to make that
problem go away.

Johnie · « **Reply #12 on:** June 05, 2008, 10:11:26 AM »

A little tip I got off this board...take some nylon rope or some guys use some paper towels. Stuff that around that seal between the fins. You won't have it hitting your legs anymore. In fact, I used the rope as it is easier to push in between the fins. Not only do I not have oil on my leg, but it no longer seeps onto the fins. When it gets pretty wet, change the rope. Won't worry about that gasket until I need to pull the engine for something major. Push it all the way into the gasket and you will not even know it is there.

MikHalifax · « **Reply #13 on:** June 05, 2008, 11:35:44 AM »

Thanks for the great posts, I'll take a lot at it.

Mike

chopstar500 · « **Reply #14 on:** June 05, 2008, 01:46:33 PM »

Quote from: MikHalifax on June 04, 2008, 06:17:25 PM

A few more. It's ugly and needs a lot of TLC, but man does it fly.

Hey man... don't fret. Mine started out looking just as bad as yours. I had the same leak, but resolved it with new gaskets and the aforementioned o-rings during my rebuild. Tons of elbow grease and few $$$ (ok, maybe more than a few) later...

MikHalifax · « **Reply #15 on:** June 05, 2008, 02:05:15 PM »

Very nice looking! I've got a lot of elbow grease to go!

Johnie · « **Reply #16 on:** June 05, 2008, 02:56:41 PM »

YIKES...very nice bike Chopper. Love the bikes in the house!!!

tom8Toe · « **Reply #17 on:** June 27, 2008, 06:15:30 PM »

Quote from: brianzenk on June 05, 2008, 09:33:23 AM

Be sure to check the oil seal on the
tach where it hooks into the engine and
make sure it is not the problem. I ordered new
oil seals from the honda dealer to make that
problem go away.

Sorry, I don't mean to hijack the thread, but Brian, I just realized mine may be leaking from the tach seal on my 400/4. In order to replace the seal, do you happen to know if it will require taking the head off or will I just simply replace the seal thru the opening where the cable enters the engine head?

Regards,
Chris

bradweingartner · « **Reply #18 on:** June 27, 2008, 06:23:34 PM »

Quote from: Johnie on June 05, 2008, 10:11:26 AM

A little tip I got off this board...take some nylon rope or some guys use some paper towels. Stuff that around that seal between the fins. You won't have it hitting your legs anymore. In fact, I used the rope as it is easier to push in between the fins. Not only do I not have oil on my leg, but it no longer seeps onto the fins. When it gets pretty wet, change the rope. Won't worry about that gasket until I need to pull the engine for something major. Push it all the way into the gasket and you will not even know it is there.

great idea! Except it reminds me a little too much of a certain femalian leak-stop product.

tonycb650 · « **Reply #19 on:** June 27, 2008, 08:22:58 PM »

damn,chopstar!! where can i find some of THAT elbow grease? Nice bike!

crazypj · « **Reply #20 on:** June 28, 2008, 12:04:42 AM »

Its overdue for changing. Usually I do them when oil reaches 4th fin from gasket head, your pic shows it on 5th fin on right side

Doesnt seem to matter what O' rings you use, they all fail eventually ( mine go at about 10,000 miles)
PJ

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Author Topic: Oil Leak from the Head (Read 7450 times)