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cb550newbie · 09-16-2009, 07:13 AM

Hi all,

Sometimes when Im at a stoplight blue smoke will pour out of the exhaust. This only happens I'd say at 10% of the time, the rest no smoke.
I know blue means burning oil, but what could the problem be that it only happens a small fraction of the time?

oh and I have a 1975 CB550 Four, with only 4700 miles on the engine. And it really runs amazing other than the smoke.

Thanks again in advance for any information!

seruzawa · 09-16-2009, 08:09 AM

Could be the valve stem seals are worn and when enough oil pools in the head it leaks into the cylinders. Also might be a problem with the oil control valves in the cylinderhead.

Anyhow that's my wild guess. To replace them you need to remove cylinderhead which means you need to remove the engine.

Kenneth_Moore · 09-16-2009, 08:49 AM

Quote:

Originally Posted by seruzawa

Could be the valve stem seals are worn and when enough oil pools in the head it leaks into the cylinders. Also might be a problem with the oil control valves in the cylinderhead.

Anyhow that's my wild guess. To replace them you need to remove cylinderhead which means you need to remove the engine.

It's a good guess; I was going to say valve stem seals too.

cb550newbie · 09-16-2009, 12:13 PM

Thanks for your responses!..

any ideas how much would something like that cost?

longride · 09-16-2009, 12:16 PM

"Anyhow that's my wild guess. To replace them you need to remove cylinderhead which means you need to remove the engine."

I thought you could get the heads off with the engine in? Never did it, but I thought they were designed like that.

acecycleins · 09-16-2009, 12:34 PM

When I get blue smoke coming from my tailpipe my wife will ask me to go to the deck.

12er · 09-16-2009, 12:40 PM

Sounds about right, if it was water cooled I would say could be a head gasket and your steaming coolent but not the case here.

seruzawa · 09-16-2009, 12:44 PM

IIRC you have to pull the engine on Honda's to get at the head. It's going to cost a lot if you go to a dealer. Over a grand. If you can find a dealer who will touch a biker that old. Many won't.

Or if you are mechanically inclined you can do it yourself. It's really hard, but you need tools and a manual.

I doubt that the bike is worth the cost of repair.

mscuddy · 09-16-2009, 02:44 PM

It also may be a head gasket letting loose. Old Hondas are notorious for head gaskets getting ossified and leakning oil into a cylinder. Pull the plugs, the dark one will be the cylinder that's burning oil. You can remove the head with the motor being in the frame. Get a cam-chain cutter, and a master link from Honda, they still stock 'em. Buy a manual for the marks you use when lining up the cam/crank marks. It's not that hard.

While you're at it, go get the cylinder head re-worked, so you can blow the lower end up with all that new-found compression. Or just ride that old Honda 'till it makes a good coat-rack.

seruzawa · 09-16-2009, 05:49 PM

Quote:

Originally Posted by mscuddy

It also may be a head gasket letting loose. Old Hondas are notorious for head gaskets getting ossified and leakning oil into a cylinder. Pull the plugs, the dark one will be the cylinder that's burning oil. You can remove the head with the motor being in the frame. Get a cam-chain cutter, and a master link from Honda, they still stock 'em. Buy a manual for the marks you use when lining up the cam/crank marks. It's not that hard.

While you're at it, go get the cylinder head re-worked, so you can blow the lower end up with all that new-found compression. Or just ride that old Honda 'till it makes a good coat-rack.

You can pull the 550s head in the frame? Cool. I thought that only Kawasakis allowed such ease of owner maintenance.

09-16-2009, 07:13 AM	#1
cb550newbie Registered Member Join Date: Sep 2009 Posts: 3	smoke Hi all, Sometimes when Im at a stoplight blue smoke will pour out of the exhaust. This only happens I'd say at 10% of the time, the rest no smoke. I know blue means burning oil, but what could the problem be that it only happens a small fraction of the time? oh and I have a 1975 CB550 Four, with only 4700 miles on the engine. And it really runs amazing other than the smoke. Thanks again in advance for any information!

09-16-2009, 08:09 AM	#2
seruzawa Robby Join Date: Nov 2001 Location: 8501 ft. Posts: 16,803	Could be the valve stem seals are worn and when enough oil pools in the head it leaks into the cylinders. Also might be a problem with the oil control valves in the cylinderhead. Anyhow that's my wild guess. To replace them you need to remove cylinderhead which means you need to remove the engine. __________________ I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I watched c-beams glitter in the dark near the Tanhauser Gate. All those moments will be lost in time, like tears in the rain.

09-16-2009, 12:13 PM	#4
cb550newbie Registered Member Join Date: Sep 2009 Posts: 3	Thanks Thanks for your responses!.. any ideas how much would something like that cost?

09-16-2009, 12:16 PM	#5
longride Super Duper Mod Man Join Date: Nov 2001 Location: Anywhere they let me Posts: 10,484	"Anyhow that's my wild guess. To replace them you need to remove cylinderhead which means you need to remove the engine." I thought you could get the heads off with the engine in? Never did it, but I thought they were designed like that. __________________ I'm a knucklehead

09-16-2009, 12:34 PM	#6
acecycleins Founding Member Join Date: Jun 2007 Location: North Georgia Posts: 4,125	When I get blue smoke coming from my tailpipe my wife will ask me to go to the deck. __________________ "Slack" - a state of being in which everything flows smoothly.....a frame of mind so at ease that the universe naturally cooperates.

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09-16-2009, 12:40 PM	#7
12er Founding Member Join Date: Nov 2001 Location: SF Posts: 2,702	Sounds about right, if it was water cooled I would say could be a head gasket and your steaming coolent but not the case here.

09-16-2009, 12:44 PM	#8
seruzawa Robby Join Date: Nov 2001 Location: 8501 ft. Posts: 16,803	IIRC you have to pull the engine on Honda's to get at the head. It's going to cost a lot if you go to a dealer. Over a grand. If you can find a dealer who will touch a biker that old. Many won't. Or if you are mechanically inclined you can do it yourself. It's really hard, but you need tools and a manual. I doubt that the bike is worth the cost of repair. __________________ I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I watched c-beams glitter in the dark near the Tanhauser Gate. All those moments will be lost in time, like tears in the rain.

09-16-2009, 02:44 PM	#9
mscuddy MODERATOR X Join Date: Jun 2007 Location: Next to my still checkin the temp. Posts: 5,444	It also may be a head gasket letting loose. Old Hondas are notorious for head gaskets getting ossified and leakning oil into a cylinder. Pull the plugs, the dark one will be the cylinder that's burning oil. You can remove the head with the motor being in the frame. Get a cam-chain cutter, and a master link from Honda, they still stock 'em. Buy a manual for the marks you use when lining up the cam/crank marks. It's not that hard. While you're at it, go get the cylinder head re-worked, so you can blow the lower end up with all that new-found compression. Or just ride that old Honda 'till it makes a good coat-rack. __________________ A gun is a tool, Marian; no better or no worse than any other tool: an axe, a shovel or anything. A gun is as good or as bad as the man using it. Remember that.