Question about oil changes.

[Dave20046]

If you don't swap the filter the oil will be black in a day anyway!

[SoulKiss]

Originally Posted by jambo

That's what it's for...



I would suggest sticking to the mileage unless you're going to go down the route of actually analysing your oil for PH content etc to see when it needs changing (only really viable if you spend time in a chem lab or are doing it to further scientific study).


Jambo

What you mean like what the OP does on a daily basis anyway.......

*Awaits post from ASH asking what can be used as an indicator, ie PH values etc*

[STRAMASHER]

Every 4000mile , oil and filter. Commuting and thrashing. Often the same thing. I am at just over 20k.

Changing the oil and filter on the other Suzi tomorrow as its been mostly laid up since november. Every 4k on that too.

[Dave20046]

I'm sure oil isn't ph neutral anyway and who's to say what level of toxins it needs to start doing damage?
Would take some hefty research for the sake of changin your oil.

[jambo]

Originally Posted by Dave20046

I'm sure oil isn't ph neutral anyway and who's to say what level of toxins it needs to start doing damage?
Would take some hefty research for the sake of changin your oil.

...which is why no one ever does, as it costs a fair bit to do this. Some long-distance haulage companies apparently do this to monitor the oil in their lorries as they do such huge mileages. But for a motorcycle specific oil in a road bike there would be no point.

Oil may not be PH neutral, but over it's use especially lots of cold starts it ends up retaining acids apparently. This is one of the indicators that the oil could use changing.

James

[yorkie_chris]

Dunno what pH oil starts off as, but it has buffer compounds in it to keep the pH fixed. Cold starts put water and acids into the oil. I think these have a bad effect on the viscosity and VI's.

Other stuff is VI compounds which are polymers which unwind with heat, to increase viscosity when hot (gives it it's multigrade properties). These break down over time.

There are also solid contaminants too small to be caught by the oil filter an oil change gets rid of.

Lots more to it that "ahhhrg my oils gone black!". RTFM.

[yorkie_chris]

Originally Posted by kurtis.randle

eg it could be used as an oil change indecator ????????

No.

Originally Posted by jambo

Oil getting black isn't in itself a problem, it shows that the various containments are being held in the oil not deposited in the engine pathways.

Or as my mum once commented when I mentioned how fast my oil went black once changed in my SR125 "This shouldn't surprise anyone that knows that fire's involved in how that engine works" Cheers mum

That said, the service intervals for the SV are 3,500 miles, and town miles aren't the kindest, I'd be keeping closer to 4K then 5.

Jambo

Good points ther jambo...and mum jambo lol

I read in my handbook the service intervals are 4-6 thousand miles, hence why i choose 5000 miles (also makes it easy to keep it up and ties in nice with valve clearance checks)

Originally Posted by SoulKiss

What you mean like what the OP does on a daily basis anyway.......

*Awaits post from ASH asking what can be used as an indicator, ie PH values etc*

stick in a (calibrated) pH meter. With all that blackness, using a chemical indicator or pH sticks might be a futile exersice Would be fun to run fresh and used oil through a HPLC or something (this separates out the components in the mixture) and then pass that ontot a mass spectrometer.

RE: oil filters; embee, I used genuine suzuki filters. I may have had a rich-running bike, since I havnt changed the air filter since ive owned it. I have changed it now though. I'll have a go with the choke plungers, it wouldnt harm to clean them up anyway.

I'll start changing the oil more regularly aswell; 4000 miles seems like a good plan. Thanks for the replies so far guys

[Sid Squid]

Originally Posted by Dave20046

If you don't swap the filter the oil will be black in a day anyway!

Even if you do change the filter it'll be black in, oooh, about thirty seconds anyway - even changing the filter doesn't get all the old oil out which will immediately colour the new oil.
BTW, for anyone worrying about it this isn't a problem.