Excess Oil | GTAMotorcycle.com

Excess Oil

M

Merkid

Well-known member
I just took ownership of an older Bandit 1200. I wanted to go back to a true UJM air/oil cooled engine design.

The previous owner had a local shop do an oil change just before winter storage. I kept looking at the glass eye and wondered why the oil level would not show any top level even after leaning the bike over. Upon start up, the engine was billowing out blue smoke for about 4 minutes then cleared. I dropped the drain plug and caught about 750 ml of oil in a container. The glass eye then showed the correct oil level. The invoice for the oil change shows the mileage at the time and with it's present reading, it looks like the bike travelled 1300 kms.

So while I haven't taken the bike out yet for a solid run yet, I am wondering what could have been damaged inside with 3/4 of a litre overfill?
 
And spark plugs, although if it was hitting on all four cylinders while test-running it, any carbon built up should clear out after a good thrash.
 
Likely what happened is that whoever did the oil change checked the level on the side stand instead of straight up and down.
We had a big cruiser show up at my buddy's shop that would not start. The owner had done a recent oil change and put in over 2 litres too much.
It was hydraulic locked - starter wouldn't budge it. 750 ccs is too much obviously, but not likely enough to cause any permanent damage.
 
"the engine was billowing out blue smoke" <- burning the oil that was forced past the piston rings.
Certainly not good for your engine.
 
Trials said:
"the engine was billowing out blue smoke" <- burning the oil that was forced past the piston rings.
Certainly not good for your engine.
Click to expand...
Or, as I suggested, the air filter is completely contaminated from the blow by out of the crankcase vent breather.
Let's check the simple things first, shall we ?
 
If the oil level is high enough, such that it comes in contact with the spinning crankshaft, the oil can be beaten into a foam. This foam is a compressible substance which can cause fluctuating oil pressures to the point where it cannot maintain a separation between shafts ( crankshaft, camshaft ) and their bearing surfaces. This can quickly destroy these components.
Google “too much engine oil“ for more on this.
 
justmike said:
If the oil level is high enough, such that it comes in contact with the spinning crankshaft, the oil can be beaten into a foam. This foam is a compressible substance which can cause fluctuating oil pressures to the point where it cannot maintain a separation between shafts ( crankshaft, camshaft ) and their bearing surfaces. This can quickly destroy these components.
Google “too much engine oil“ for more on this.
Click to expand...
"The previous owner had a local shop do an oil change just before winter storage."
I seriously doubt the machine could have been run long or hard enough for fluctuating oil pressure to be an issue in this case.
 
TK4 said:
Or, as I suggested, the air filter is completely contaminated from the blow by out of the crankcase vent breather.
Let's check the simple things first, shall we ?
Click to expand...
Personally I would check everything, but that's just me.
I've seen what engines look like on the inside a couple of times and have a pretty good idea what sh*ts its pants and what doesn't, ymmv.

... results of this issue would be different for every different design engine.
Most modern motorcycle engines collect oil from blow-by in the airbox and blow-by is not an abnormal condition, says so right in the service manual ;)
 
Trials said:
Personally I would check everything, but that's just me.
I've seen what engines look like on the inside a couple of times and have a pretty good idea what sh*ts its pants and what doesn't, ymmv.

... results of this issue would be different for every different design engine.
Click to expand...
After checking all the other stuff a simple compression/leakdown test could be performed to verify internal condition.
Its kinda like chicken soup for a cold - can't hurt might help...?
 
TK4 said:
After checking all the other stuff a simple compression/leakdown test could be performed to verify internal condition.
Its kinda like chicken soup for a cold - can't hurt might help...?
Click to expand...
He can borrow your compression tester
 
TK4 said:
"The previous owner had a local shop do an oil change just before winter storage."
I seriously doubt the machine could have been run long or hard enough for fluctuating oil pressure to be an issue in this case.
Click to expand...
1300 kms. according to OP - that’s a fair amount.
 
Thanks for the feedback. Since my post I did find excess oil in the air box along with a soaked air filter. Changed it out and released the air box drain hose plug to get the residue out. Plugs which were black, oily and were replaced. Filled it up with Shell E-free premium with sea foam added and did about 35km on it before the cold temps took their toll.

I will open up the Chinese can on it next and remove what is left of the internal packing (if any). Cold starts did not reveal any smoke so I may have lucked out.
 
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