oil running from exhaust

[steelcat]

At woork, we often use liquid nitrogen for bearings on Hyd. Cyl. & such. A couple of times we have use dry ice. Which worked well. Just have to be a bit faster. Heating your head in the oven to 250 will also help. Just make sure the each valve guide is seated before sarting on the next one. Once the guides warm they will expand to normal size & the problems start. Good luck.

[mitch]

Dry ice

Hey cbird cant he at least put it in his whiskey. Make for a dry drink lol !!!!!.......MITCH

[DEmily]

Mitch,

I'll try it if you do

[mitch]

Thanks

Thanks but no thanks i better pass on that one, gotta raise my 6 yr old girl.Still like biking hard to do 6 ft under!.........MITCH

[Geezer]

Re: Dry ice

Originally posted by mitch
Hey cbird cant he at least put it in his whiskey. Make for a dry drink lol !!!!!.......MITCH

On the old Star Trek next gen, they used to put a thimble sized chunk of dry ice in the Klingon drinks to make them steam. It's OK to do but don't breath to much of the fumes. Too much CO2 is bad for you.

Geezer

[Geezer]

Originally posted by cbird
You can get dry ice at Baskin Robbins. Don't eat it!

Pick up a pint of strawberry cheescake icecream while you're there. It'll give you something to do while the guides are cooling and the head is heating. ;o)

Geezer

[DEmily]

Sounds like a plan!!

[morticiaann]

oil running from exhaust

Mine did that after I stripped a pilot jet. The head stripped off and I ruined the seat trying to drill it out. The number four cylinder wouldn't fire off of idle but it would when the mains came into effect. Solution was to replace all four carburetors. Oil used to leak out of the exhaust about a quart every month. It left a stain everywhere I parked it.

[DEmily]

So how did that cause oil to run through the exhaust? Was the number four cylinder blowing oil or where was the oil coming from?

[morticiaann]

reply to DEmily

I thought you might be surprised. Because the number 4 cylinder didn't fire - oil leaked past the #4 rings. 1,2 &3 ran fine. I guess that the oil in the cylinder normally burns with gas so that it isn't visible in the exhaust. But I had oil everywhere. I mean; I repaired it because I had to park my xs11 at work - and it practically looked like a trail of oil all of the way down the street from my home. And a big puddle for the boss to step in.
I only damaged the #4 carb. I drilled the pilot jet out because it got stuck, and cemented the seat, but I would probably need dentistry tools to fix it. I unscrewed the #4 needle valve about as far as it would go and the engine started to run normally. Except for the oil leak, I hated to repair it, because it was really a lot faster.
I had to replace 4 carbs because of a $3 part. I see you're in a bind similar to this having to repair everything in the head.
I'm sure the oil out of the exhaust was because really a lot of oil goes into the cylinder to lubricate it. I've seen no wear at all on my cylinder walls which indicates there is a lot of lube on the piston sliding surface.
I was in quite a bind because of carbs and I kept it going but I had an XJ550 just rebuilt to ride instead. You've got a possible leak in your valve train. I hope to point out that if all of your cylinders aren't firing, for any reason, oil will push past the rings and out the exhaust.
When this happened I was putting Dynojets in. I wanted a 20% horsepower increase with shined ports and a header. I thought; well I'll just clean my pilot jets. I found that if these don't precisely fit into their holes the engine won't accelerate smoothly. When I put carbs in with 4 good pilot jets the leak disappeared.
I know it's aggrivating for a little part to cause such a mess.
The bottom valve spring seat isn't very thick and I doubt it would cause you a big oil leak. I would replace it or the spring will gore your head. Putting the right shim in shouldn't be hard.

[ratbyk]

Excess Oil Consumption

I understand what Michel is trying to say. When combustion takes place in the cylinder, combustion pressures pass down into the top piston groove and force the top ring very tightly against the cylinder wall. As the piston and rings move down the cylinder with this extra pressure the rings scrape excess oil off of the cylinder wall and deposit it back into the crankcase.
If the cylinder doesn't fire there is no excess ring pressure from combustion and instead of scraping the oil off and down the ring will pump "UP" any surplus oil on the cylinder walls. This will result in excess oil consumption in the form of raw un-vaporized oil being pumped out into the exhaust system.
Clear-as mud, ah what.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"

[strom]

Thats very likely my problem too. But I refuse to be scared carbless by a little thing like a leaky pilot jet seat (mine are also in kaka shape). I'll get the Bastard running...

LP

[DEmily]

morticiaann

I see what your saying. I'm am real sure my issue is that valve guide. I am suppose to get it in on Tuesday, so hopefully I will be riding next weekend.

[strom]

OK I'll post my problem here...

When cold, bike ran fine, when a bit warmed up, it smoked badly from the right exhaust, left one was not that bad... barely noticable....
In bout 100 km 2 dl of oil dissapeared. Smoke screen style, a bit came out unburned (oil). left exhaust was badish, the right one was terrible.

So.. today we took off the head and cyls...

cylinders are not as good as they should be, but since they're at 71.4 something it's still OK.... normal is 71.5 and replace/rebore at 71.6 mm. So a good polish will clear the weird spots that appeared while the bike was sitting for 6 years.

Pistons are at 71,0, but I didn't do a detailed measurement yet.

The rubber o-ring red thingies beneath the cylinders were torn, except one.

#2 and #4 carb intake boots seemed wet with gas...

#1, 2 and 3 were wet with oil... or it seemed like oil...

When I turned the cyl. head around and poured gas into combustion chamber, the level lowered significantly on all except #4.

So... how can I check if oil might be seeping through valve seals or valveguides/o-rings? Valves will have to be reseated, but I still don't know where the leak is.
When I left it on idle to warm up, bout 1 min it ran fine, than suddenly lotsa smoke and stuff. Oil was fresh, more or less.
Almost forgot... compression from #1 to #4 is
11,9
12.0
11.1 (got to 12 when some oil was poured through spark plug hole)
12.5

Any ideas?
O-rings that come beneath the valve guides were not changed, but I got a new set sitting on the shelf.

LP

[morticiaann]

When I turned the cyl. head around and poured gas into combustion .....

I think you obviously have bent or worn valves. Turn the head upside down and pour water into the 4 cylinders. Look for leaks.
Turn the intake ports down and fill the exhaust ports with water.
Do the same for the intake valves. If any leaks out then you have to take the valves out and check for damage.
If possible, put your valves in a drill and see if they wobble. Replace any valve that does. (Once, I didn't do this and I was really surprised on another rebuild, that my valve leaks were due to bent stems.) Make sure the valve faces are smooth and not pitted.
The repair manual gives you a tolerance in mm for your valve guides and stems. Measure the stems to see if they are full size. Put them in the valve guides and push sideways for this tolerance.