White smoke coming from tailpipe - 1980 Honda CB 650

[HazMatt]

I recently installed pod air filters in place of the stock air box assembly. This required new main and slow jets as well. I'm also running the valve cover breather hose to a breather filter, instead of the airbox where it used to go.

When I first started the bike after adding the new pods and jets, I think I had the pilot air screws out too far, allowing too much gas into the mixture, and I fouled out spark plugs 2 and 3 shortly after starting it. This is when I had white smoke coming out of the tailpipe, as well as the tailpipes where they are bolted to the engine - but only pipes for cylinders 2 and 3. There was no white smoke when I ran the bike on only 2 cylinders.

Then I adjusted the pilot air screws (turned them in a bit to make the mixture less rich), and installed new spark plugs. The bike fired right up on all 4 cylinders, and sounded healthy enough - except now there is white smoke coming out the tailpipe, and it appears to come out of pipes 2 and 3 (where the fouled plugs were).

My guess is that the piston rings are worn and oil is getting into the combustion chamber, etc. But I'm really hoping this is not the case. If anyone knows of anything else I can try before going in there and making sure the oil isn't getting past the pistons, that would be great.

This bike is super hard to find parts for (the CB 650 was only made from 79-82, and this specific model was only 79 and 80, and it's almost impossible to find parts).

Any advice anyone might have is greatly appreciated.

Thanks.

Matt

PS: I took a video of the issue - you can view it on Youtube here: http://youtu.be/9dQoWo4sniQ

 

[blackbuddha1]

are those Emgo pods? the rubber mount boot on them partly blocks the small air holes on the carb! I don't think that would cause that kind of smoke but then again it's 5am no coffee yet let me ponder a little longer. Mainerider or Volker on CB650 fourm might have your answer

 

[blackbuddha1]

I have been able to fine parts for CB650 through RubberCityVintageCycle they have many contacts! phone#3305357282 talk to Chris

 

[mydlyfkryzis]

Oil is silver/gray smoke. White is usually just water vapor. Black is too rich a mixture....

Not sure why only 2 cyl smoke white, but water is a natural product of good combustion. PErfect combustion of gasoline yields H2O and CO2... The Water is in vapor form, but condenses and appears as white vapor is the air is cool. Watch a car on a cold startup....water will come oout of the tailpipe until the exhaust pipes get hot enough to keep everything in vapor form. It's why cars have white vapor out the tailpipe in the winter. The cold outside air is below the dewpoint of the vapor, so it condenses into the white smoke.

Maybe a pic would help...or a video

 

[Bert Jan]

Did you mount new 'gaskets' between the cilinder-head and header-pipes? by the looks of it, they're missing/shot.
Smoke color is hard to see on video, you could ride 'er for a while and check if the smoke goes away.

I would just ride 'er. Hard.

 

[mydlyfkryzis]

Missed the video earlier, was using phone...

Bert Jan is right...you need gaskets on the muffler....so the smoke may be on all 4 cylinders.

Looks more like oil smoke...water vapor dissipates quickly...That smoke lingers....

So oil is from valve guides and or rings.

Is your oil level right? Overfilled can overwhelm the rings.

Plugs? Look Black and sooty?

Definately not fuel to me, looks a lot like oil...

 

[HazMatt]

I actually haven't changed the oil since last season. I was planning to put some slightly thicker oil in this time to see if it has a harder time getting past the pistons (if that is indeed the problem). The oil levels are right - definitely not overfilled.

Could this be a product of old oil? Will putting new oil in help at all?

I have not put gaskets between the cylinder heads and the headers. I assume they're there, but it's definitely possible they're shot. However, that won't fix the immediate issue of the burning oil.

Thanks for the comments! I think I'll change the oil, and then go for a nice ride. The compression feels good, and she's really responsive. If there was no smoke coming out of the tailpipe I'd say she was running perfectly!

 

[VonYinzer]

If you're running worn/damaged/no exhaust gaskets you run the very serious risk of burning up those pistons
DO NOT ride the bike until you replace those gaskets.