[Gun]

White smoke coming from my front jugs exhaust on a 1996 vulcan 800 a
Mileage has gone down from about 50 to 40 mpg
Seems I am burning oil as my oil level is slowing dropping, however, my breather also enjoys coughing up oil regardless of me routing the breather tub up and over the jugs with an air filter at the end, so i may be losing my oil that way and this smoke COULD be the result of coolant through the head gasket, no?

Any advice / ideas on resolution are much appreciated.

 

[lkwinnipesaukee]

How does the smoke smell? Sweet, kind of syrupy? If yes, then you are burning coolant.

Burning motor oil is blue.

 

[edwinner]

I think your bike just elected a new pope.

 

[Marek]

How does the smoke smell? Sweet, kind of syrupy? If yes, then you are burning coolant.

Burning motor oil is blue.

Yup! ^^^ White smoke is always moisture\water . Now , if you just wsashed the bike or pulled it out of storage from a damp enviroment that could be just some water that will burmn off . If the smoke smells overlly "sweet" then that would indicate you are burning antifreeze . Have you overheated recently/ spent a long stretch in slow moving trafic jam ? Start by checking your coolant level and color , then check your oil ..if either looks like a creamy white milkshake DO NOT RUN YOU MOTOR !!!!!! Coolant in your oil will strip the slick coating from all your bearings therefore killing them if you run it . If both are fine run the bike gently for a few miles to heat everything out . the bike should not smoke after about 5 min of running but do not do the sitting still in the driveway (not enough air moving may over heat ) . I hope this helps a bit .

 

[Gun]

smells like heavy exhaust, like i'm next to a big truck... I'll have to put my sniffer closer to see if i'm getting a syrupy scent.
smoke seems to go away after warmed up.

 

[Gun]

correction, rear jug. Not sure how i remembered that wrong.

 

[Bob Myers]

correction, rear jug. Not sure how i remembered that wrong.

Ditto on white smoke is water/coolant. Check that level first, oil second. If you see milky oil DO NOT RUN, as was said above.
It is possible to have condensation in the air filter housing if the temps are swinging from shirt sleeve to below dew point but it only showing in rear cyl would be very weird since both suck fuel and air from same single source.

 

[Gun]

Well upon further review the smoke IS slightly bluish. I had to hold a black board behind it to see the difference as it's been overcast and poor lighting lately.
just to be safe i checked the coolant, it's topped off exactly to the point i filled it, and looks fine, no white milky deposits etc...

so i'm burning oil in one cylinder I assume.
causes?
solutions?

 

[BikeTechJLM]

Could be two things, valve guide seals or rings. You said your mileage dropped so I'd say worn rings. (slight loss of compression = mileage drop)

 

[Marek]

Causes? Valve seal or piston ring ..since you are spitting oil out of the breather I'd say worn piston ring ( combustion presure is also blowing by the ring and presurising the crankcase = oil spitting out the breather ) But that is just a long distance guess from a backyard mech..

 

[Gun]

makes sense.
I'm comfortable working on bike engines, but have only worked on 1960's hondas... I don't have a bike lift or other tools i'd imagine a larger bike would need. how much do you think the shop would gouge me to replace my piston rings?

I imagine I can do this myself if i utilize one of my buddies garages, but i hate having my bike down for too long. :/

 

[Gun]

oh, i'll stop being lazy and call the dealership...


oi, they throw at me 6 hours of labor and 500 bucks...
no thanks, I'll figure this out on a sunday with a few beers.
any major harm in running the bike as is? anything else that i should check/replace while i'm in there?

 

[Bob Myers]

Without a lift you can pull the engine and have it sitting on the bench ready to be destroyed or whatever in less than 90 minutes, alone.
I would opt for a compression test, and or a leakdown test first though. Fuel mileage drop is not totally indicative of rings gone bad, neither is burning oil on one cylinder. It could simply be the epa removal that spawned the oil burning, and drop in fuel mileage. put it all back, since it really did not help performance one iota any way, at least put it back to see if it stops putting oil in the air box, and burning oil.

 

[BikeTechJLM]

So true!! BEFORE you rip anything apart always do compression and leak down test. The best way to diag and an easy way to pinpoint exactly where your problem might be!

 

[Gun]

EPA stuff has been off of the bike since I've owned it.
put on about 4,000 miles in the pacific north west, sea level to 4,000 ft. and about 1,000 miles up here at 5,000 feet in utah.
didn't notice the issue until the 3rd month of riding regularly. (i rode in jan, feb, march, and didn't see any smoke till april)


the crank case breather has been coughing oil since i had the bike. when i first changed the oil, there was 3.5+ quarts in it... not sure if that overfill had anything to do with it.

mileage didn't drop until this last month as well.

I will go get a compression test done.

 

[BikeTechJLM]

The EPA stuff that has been removed wont make you burn oil or cough oil out the case breather. All it does is force air into a port over top the exhaust valve. The purpose is to add air to the exhaust gasses to clean them up and possibly burn a little more while in the exhaust pipe so it'll get better readings. Get the compression and leak down and that will tell you if you need ring or if you have some other problem. Good luck!

 

[cosmicsclassic]

I'd do a compression test, cylinders should be fairly equal, if there's a 30 or 50 pound difference there could be a problem. Next squirt a little engine oil into cylinders threw spark plug hole, a teaspoon full. Do another comp test. If pressure comes up rings are bad,stays the same , valves are bad, along with valve guide seals. If rings are bad, running it may score the cylinders beyond repair.

 

[Pa. Patriot]

So, any follow-up? What did it end up being?