Cleaning air box?

[scottrc88]

does anyone have any good methods for giving an oily air box a good cleaning?

[husky03]

take filter out, spray inside with brake cleaner, wipe it clean, allow to dry, refit air filter pop a wheelie.

[Stonesie]

Everyone should have a can of brake cleaner 'in stock' it's one of the most useful cleaning products ever :)

[yorkie_chris]

Don't bother... some oil in there is normal.

[fastdruid]

what yc said, drain what you can and leave it.

Druid

[scottrc88]

thanks for the advice folks. if its normal for a bit of oil to be in there, doesn't that mean that the paper in the air filter will absorb the evaporating oil and effect air flow?:confused:

[Stonesie]

Don't worry, any oil in there will not evaporate... ever, and if the filter looks dry and is relatively clean then that's good to go too.

"Don't bother... some oil in there is normal."

Mine is bone dry in there, oil level is at Max too.

[fastdruid]

thanks for the advice folks. if its normal for a bit of oil to be in there, doesn't that mean that the paper in the air filter will absorb the evaporating oil and effect air flow?:confused:

No, it wont evaporate and even if it does get into the filter it'll just help with filtering dust as the dust particles will stick to the oil[1], if the entire thing was soaked in oil it might affect it but even then not for long!

"Don't bother... some oil in there is normal."
Mine is bone dry in there, oil level is at Max too.

Depends on how you ride it and the condition of the engine, cane it, have blowing rings or fall over and you'll get plenty!

Basically the crankcases are fed into the airbox, when the engine gets hot and there is a lot of oil movement you get oil mist that ends up re-condensing in the airbox (the idea being to re -condense it and feed it back to the engine but not all makes it and ends in the airbox).

Druid

[1] This is the theory behind the K&N 'oiled' filters.

[embee]

Broadly speaking oil doesn't evaporate.

The oil gets there by being carried over in the blowby gas which is led to the airbox via the breather tubes. Blowby (past the piston rings) is perfectly normal and unavoidable. While breather systems are developed to separate oil from the gas it is never 100% effective so inevitably some oil reaches the airbox. When it exits the pipes into the large volume the velocity reduces suddenly the oil mist can drop out, so the inside of the airbox will become oily. This then naturally collects at the low points.

Blowby is taken back into the intake to avoid the emissions of blowby gas direct to atmosphere (it's a legal requirement on the manufacturers).

It should not be swimming in the stuff, but it'll always be slightly oily so no need to worry about cleaning it all out too much, just wipe with some paper towel/rag and pop it back together. It'll soon reach equilibrium again anyway.

This is just one reason why overfilling with oil is not a good idea, it increases oil carry-over dramatically.

[scottrc88]

Lol I detached the whole box ready to give the whole thing a clean up before i installed the new filter. Thanks for the input people - it makes life a lot easier for people like myself with limited mechanical knowledge.:rolleyes:

[Sid Squid]

Don't waste money on brake cleaner for this job - there's petrol in your isn't there?