Burning Oil: Is it normal? How much is too much?

[SWriverstone]

I did a search for previous threads on this and didn't find any (but I confess I didn't wade through the 15 pages of search results---I got lazy!   )

The subject of bikes burning oil after a certain age/number of miles has come up often in other discussions. I'm curious about this (and know nothing about it). Specifically...

• Is it perfectly normal for bikes to eventually burn some oil (regardless of amount)?

• What are the thresholds for this? In other words...
     - If a bike starts burning oil at _______ miles, you should be concerned. (Fill in the blank!)
     - How much oil loss is considered bad? (From the "High" to "Low" lines in your sightglass? 1/2 quart or more?)
     - Is *any* amount of oil loss always a sign that something's wrong in the engine?
     - Is any amount of oil loss a sure bet that the engine's going downhill fast and on its last legs?

I mentioned in another thread: with my 2007 Wee Strom (37K miles)...I'll change the oil, top it off to the "High" line in the sightglass...and after maybe 3-4K miles (I don't know how long exactly) I'll notice the oil level has dropped to the "Low" line in the sightglass.

Is this totally normal and no big deal? Or is this an "Oh crap, you better get rid of that bike FAST!" kinda thing?  

Again...just trying to understand how much is too much?

Scott

PS - Even if you're not a motorcycle mechanic or engine expert...post up anyway and let us know if your bike burns any oil with ______ miles on the clock...and when did you first start noticing it?

[Justin]

I don't know if it's normal. I know my bike has 55k on it, and I don't burn a drop between changes. Might just come down to how well the rings were broken in. Mine was broken in at high RPMs on the dyno, so they are seated really well

[veefer800canuck]

1986 VFR750, owned for 14 years and 53,000 kilometers. Never added oil between oilchanges. Ever.

1999 VFR800, owned for 12 years and 80,000+ kilometers. Never added oil between oilchanges. Ever.

That is the extent of my expertise in this area. Carry on.  

[tomek]

It all depends , air vs. water cooled , size of cylinder bore ( singles and 2 cylinders vs multies ) oem pistons vs aftermarket forged ( O.K. Wiseco ) , and yes , some manufactures are better in building bullet motoers then others but I won`t name any names .

My high mileage XX burns no oil whatsoever , but I broke the engine in properly ( pulled wheelie leaving the dealership and and  went many , many times  WOT in  the first couple of hundred miles ) .

Also distinction needs to be made between oil burning and oil evaporation , some evaporation is normal but not all oil are equal in this regard .

Having said engine oil is relatively cheap , set of new pistons , rings , bore job and labor  are  not , so basically forgitabouit and just ride the fricking bike .

[Andrew]

I had to add oil to my old 2 stroke every time I put gas in it

FJR 80k never burned a drop between oil changes. Heck after a while I just stopped checking it, when change time came around still full.

BMW R1100GS (forgot the millage) 1/3 qt every oil change (5k miles)

BMW R1150GSA (75k) 1/2 to 1 qt between oil changes (depends on brand of oil, synth seems to burn less)

Wife's Scion XB (100k) never a drop

[Kneescrubber]

If you're that concerned about it, do a leak down test.

[Rincewind]

I had a 2007 Triumph Tiger 1050 (former demo bike) that burned enough that I had to pack oil on longer trips.  It burned 200-300 ml per 1000 miles.  If the bike burned more than 1-liter per 1000 miles, it would have been considered for warranty repair.  It consumed oil from the beginning and would need top offs to last the 6000 mile oil change interval.  Pressure tests did not show any problem.  It was one of the reasons that I got rid of that bike.  I put a lot of miles on it while it burned oil.

[Kneescrubber]

...Pressure tests did not show any problem...

A compression test won't. That's why I suggested a leak down test. They aren't the same thing.  

[SWriverstone]

Okay...so someone mentioned evaporation as opposed to burning oil. Let's focus on the sight glass scenario: you change the oil and fill it til it's
 Even with the "High" line on the sightglass. 4K miles later, the level has dropped to just above the "Low" line on the sightglass.

Does this count as "burning" oil or evaporation? And you guys who say your bikes never lost a drop---are you saying that after 4K miles the level won't have dropped even 1mm in the sightglass?

Like all oil-related threads, this one seems to have some "slop" in the conversation. LOL

I broke my Wee in with an 800-mile ride home from the dealer. And the way I rode (because somehow I was convinced this was the proper way to do it) was by never holding the RPMs constant---I was constantly accelerating/decelerating between 5K-7500 RPMs (I never ran it WOT... Bt maybe that's considered the proper way to seat rings these days?)

The Wee has an (only slightly modified) SV650 engine, which from all I've heard is pretty legendary for being bulletproof.

[Andrew]

 4K miles later, the level has dropped to just above the "Low" line on the sightglass.
4k and its still in the sight glass = no problem & due for an oil change

Does this count as "burning" oil or evaporation? And you guys who say your bikes never lost a drop---are you saying that after 4K miles the level won't have dropped even 1mm in the sightglass?

Yep thats what I said, The FJR never lost a drop, never had to add oil

[Cablebandit]

If you are burning oil, stuff is wearing out. My oil level didn't drop at all between changes until about 32,000. Then it started burning about half a quart between changes.  The C14's oil level doesn't change at all at this point.

[Kneescrubber]

No offense Scott but you seem to be obsessing over nothing.

Is there a puddle of oil under the bike when you go out to start it in the morning?
Is there a 2 smoke trail from the exhaust?

You need to accept the fact that your engine "uses" some oil. Get over it and ride the damn thing.





And BTW, if it was burning oil you would know it by the smell and look of the exhaust and spark plugs.

[Mastros2]

Doesn't sound like a lot.  I wouldn't worry about it.  By your sight glass, you are losing less than 1/2 quart of oil in 4k miles.  That is nothing on an air cooled bike. I would start to worry at 2 quarts per 4k miles.

[coho]

The service manuals for both of my oilheads say that they can use up to but not more than 0.1L per 100 kilometers and not be out of spec or broken. This is undoubtedly mostly evaporation as the oil is the coolant, but is still oil going away without indicating engine dysfunction.

PS. Actual oil use has been about .5L per 3K miles.

[Cablebandit]

Doesn't sound like a lot.  I wouldn't worry about it.  By your sight glass, you are losing less than 1/2 quart of oil in 4k miles.  That is nothing on an air cooled bike. I would start to worry at 2 quarts per 4k miles.

Problem is his bike isn't air cooled. It should have the same tight tolerances of any other liquid cooled engine.

[garry]

Some bike models just use oil. My KTM uses a half quart over a 3000 mile oil change interval. Always has since new. I just top it off as needed. Seems lots of them do that. My other bikes never used any between changes.

[malbojah]

wish my bike used as little oil as yours does. Mine uses almost 2 quarts every 3000 miles

[SWriverstone]

No offense Scott but you seem to be obsessing over nothing.

I'm not obsessing at all---merely seeking information. When cablebandit said his V-Strom starting burning some oil at around the same mileage as mine, I thought maybe I should at least pay attention to it for a while just to see if mine is doing the same?

After watching it for a while, I noticed it was dropping a bit in the sightglass between oil changes...but that's it. I still ride the bike every day.

So the question popped into my mind: how much can your oil level drop between changes before you should be concerned about it? That's it.

My bike doesn't leak a drop of oil, and my exhaust is completely invisible---no smoke at all. But clearly it's "causing a bit of oil to disappear" so I'm just wondering what the range of possible causes are.

I'll continue riding the bike and plan to keep riding it. I mean, when you get right down to it, if a bike's burning (or "disappearing") oil, there's nothing you can't do about it, right? (Short of a new engine or massive engine overhaul---I mean there are no quick fixes.)

Scott

[Mastros2]

Problem is his bike isn't air cooled. It should have the same tight tolerances of any other liquid cooled engine.

Thought they were aircooled/oilcooled for some reason. Oh well.  

I still wouldn't worry though. That isn't much oil loss.  

[Skee]

My Wee has started consuming enough oil between changes to annoy me.  It now consumes about 200 mL per 1,000 miles.  So I pack a little bottle of oil to top it off on long weekend trips.  Worrying about it now running low on a trip is a PITA.  Spark plug and tail pipe look normal to my untrained eye.  I suspect a large amount of consumption can be attributed to the fact that I wring the livin' snot out of the little bitch when I ride her.  (sorry, didn't mean to get personal.)  I really don't suspect a mechanical problem; cylinder wall scratch or something out of tolerance.  I suspect it will either level off at some point, or I'll rebuild the top end if it gets progressively worse, or just get something else.  It's a f'n Wee for cryin out loud.  

This is the first motorcycle on which I followed the manufacturer's recommended break-in instructions.  Go figure.