Oil Level Rising

[125cc]

Hi folks, looking for assistance.

 

2018 YS125, air cooled, approx. 4000 miles.

 

Noted oil level rising of recent, to the extent when I checked today I had to drain out around 50-100ml (!) of oil out of the sump as it was literally flowing out of the fill pipe as soon as I removed the dipstick. The bike was serviced in August and has been ran most days on short commuting journeys (5 miles a day to and from work) hence the low mileage. It's not had a decent lengthy run for a good while due to lockdown.

The oil looks as if it could do with a change; its dark, opaque and smells of petrol. The bike has covered around 700 miles since the service. Not sure if this is moisture build-up with short journeys or if there's something more sinister at play here.

I haven't checked the air filter yet for blowback etc. (will do later on) and the bike seems to be running absolutely fine... only found this during regular checks (which I admit I've neglected recently for various reasons... lesson learned!)

 

I'm thinking about changing the oil and filter first of all, however I'm concerned there may be something else up.

 

Regards

 

125cc

[dynax]

If it smells of petrol then that needs investigating fuel is somehow getting into the engine block.

Is it a carb or fuel injection, usually more associated with carb models as the float sticks and this often results in it overflowing into the engine.

[125cc]

It's injected.

 

There's definitely a smell of petrol in the oil so I'm getting concerned.

[dynax]

Could be the fuel injector, as it's a pressurized system if the injector does not shut off properly the pressure forces the fuel into the chamber and eventually into the sump, this will also happen with the engine off

[dynax]

Might just be bit of muck in the injector or a valve stopping it from closing.

You have a couple of options you could try some injector cleaner in the fuel, or take it off and give it a clean, either way the oil will need draining and refilling probably a filter change too.

[onesea]

I would start with oil change sometime yesterday, oil is thick and slimy for a reason.  Petrol is thin and explosive and not a very good lubricant.

Also add injector cleaning fuel addative, take her for run get her warm.

 

However if you have any debris in oil when you change it reconsider.

 

Check oil level regularly, including smell.  

 

 

[Mississippi Bullfrog]

Oil will absorb combustion byproducts which can include unburnt petrol and water vapour. An engine that reaches full operating temperature will evaporate off these byproducts. One which does short journeys won't so the oil level can rise. It will then fall after a long run.

 

This is one reason I change my oil more frequently than the manufacturer's stated service intervals.

 

At your mileage it is unlikely to be engine wear, more likely to be a cold engine not purging the oil of combustion byproducts.

 

I'd change the oil and try to ensure you do a longer run on a frequent basis.

[125cc]

Thanks everyone - sounds like oil and filter is a good start. I suspect the short runs are the issue - normally it'll get a decent run along the A96 when I nip out to the folks or see friends along the road, however effing Boris and effing Nicola put paid to that. No longer a problem from this Friday onwards however. Guess what I'm up to this weekend...

 

Will let you all know of course how I get on. Thanks again.

 

125cc

 

[Stu]

Has it only started to do it since the cold weather? 

 

[125cc]

Not sure. Seems to have gotten worse since the winter.

[Stu]

It will get worse in winter 

 

The bike takes longer to warm up and the injection system compensates for the cold and adds more fuel if its not burnt properly then it can run in to the sump! 

 

This is called cylinder wash 

 

Does it get all the way to operating temp? 

 

Suzuki has a history of getting it wrong with temp sensor location placement and some bikes can read the wrong temp and always be on the cold map 

[TimR]

 Am i not the only one thinking that if you have liquid flowing out of the dipstick hole that this is more than a small increase ?

The redline is the max mark so that is s good few inches of excess fluid .

 

Are you checking the level on centre stand or on its wheels ?

[Stu]

34 minutes ago, TimR said:

Am i not the only one thinking that if you have liquid flowing out of the dipstick hole that this is more than a small increase ?

 

 it seems I missed that! 

 

Yeah that is very excessive and needs investigation 

[Mississippi Bullfrog]

Good point, that doesn't tally with needing to remove only 50-100ml of oil though. 

 

 

[TimR]

May have removed 100ml but doesn't say to what level/reference point ie tostop it pouring out and could still be over 1ltr over the max mark 

[125cc]

Hello all, an update as promised.

 

Changed oil and filter today. Way too much oil in there, I suspect it was overfilled at the garage at the last service. Oil was very emulsified which would be consistent with the short runs I've been doing for months now.

 

I also checked the air filter, it was clean although a slight whiff of petrol in the air box and a dribble of emulsified fluid at the bottom of the air box - no residue on filter or in the air pipe. Cleaned the fluid out and also checked the spark plug, which was perfect in colour and correctly gapped, so combustion seems healthy.

 

I put in about 900ml of fresh oil plus a new filter, checked when engine warmed up (as per the manual procedure I always follow) with bike on center stand, the oil level is just under the maximum mark on the stick. I took it for a good run over 20 miles at mostly 50-60mph (beautiful evening for it. Forgot how much I missed doing this!), seems to run fine, rechecked the oil afterwards, no change in level or leaks noted.

 

I also checked oil pressure immediately after the oil change (as the manual advises), oil flowed out of the bleed bolt straight away after start which indicates healthy oil pressure.

 

I'll monitor the oil level and condition carefully over the coming weeks - lesson learned, never skimp on checks - and will update this thread accordingly.