My bike consumes oil at an alarming rate yet shows absolutely no smoke or smell that would indicate it. I can top it off, start it and run it for a minute then shut down, check a couple hours later and see that it's gone down a little. If I go a hundred miles it's not even registering on the dipstick, but I went 2,500 miles without checking and it only went down 2/3 of a quart - how can this be? How is it possible for it to be burning so fast without smoke? Can anyone explain what's causing the burning and how to stop it or at least slow it down?

 

I have the exact same issue and it have almost got me in trouble a couple of times. Mine will not smoke one bit, but it will loose oil consistantly. I don't mind adding more but it would be nice to know where the heck it is going.

MDFF

 

Have you had somebody ride behind you and tell you it is definitely not smoking?

 

Yes - for hours, no smoke whatsoever.

 

Same here, no mention of smoke from anyone.

MDFF

 

Engines can burn quite a lot of oil without leaving visible blue smoke. Even with such extreme high oil consumption like e.g. 1 litre in 1000 km's, there could be no visible smoke. The unofficial norm for renovating an engine is about at that level, run it until it consumes more than 1 litre in 1000 km's. When I bought my CBR it didn't take more oil than acceptable, about 1 litre in 4000 km's. However, I runned it very hard most of the time and quite soon the oil consumption went up far more than found acceptable to me even though the bike runned extremely well. I decided to sell the bike at that point, informed the buyer (a company) that it needed some oil about every other gas fill if it was driven hard. I also tried 15W-50 oil, which is thicker, but that didn’t help. What you can do - is to live with it until it begins to blue-smoke, or hone the bores and change rings, or buy a low mileage replacement engine, or just sell it to someone not running very much or hard and definitely let him know the condition of the engine if he is bigger than you [].

 

Hi,
I had the same problem in early summer. The oil had stayed whole winter in the bike (not driven) and I thought I can drive some time before next change. Wrong. CBR seems to like to have new oil every 5000 km and also after long period of staying. I changed 10W-40 oil, drove 1000 km and chanced it again. Also filter twice. After that hole summer went OK. No extra oil consumption. Worth trying before larger reparation.

 

I have a problem with the notion of a bike that consumes oil but does not smoke or leave a mess on the floor.

My last bike (CB900C) smoked like the proverbial chimney and consumed oil - in that that case the valve guide oil seals were shot. It would be interesting to know exactly how the oil is finding it's way into the combustion chamber in the cases above.

I guess i'll just have to get over it.

 

All engines burns oil to some degree, but it may not be visible until it reaches dramatically levels. My CBR 1000 F, which at the end consumed about a litre every 1000 km's when driven hard, did never show any visible smoke at all during driving. But it certainly smelled oil when it was put back in the garage after a hard drive. I have a friend driving a year 2000 Audi car, which already when brand-new consumed about a litre of oil every 1000 km. The car doesn’t blue-smoke but always consumes too much oil, and it isn’t a leak that shows on the floor.

I guess the mechanism, unless it isn't worn valve guides, is that high pressure in engine bottom due to worn rings, will give more oil on cylinder walls than the oil rings can scrape down, and that the oil then is burned in the combustion chamber.

I found some interesting reading on http://www.performanceoiltechnology....onsumption.htm

 

As a bike ages it will use more than normal oil if you are not using oil marked as for Motorcycles. The gears in the trany will crush it and it will get by the rings. Are you using good motorcycle oil?