D400 20k mileague
Chain , sprockets , engine air filter , spark plugs , engine oil , coolant changed.
Next change is tyres hahaha

Dont waste money with branded cleaning kits...just get kerosene n the chain cleaner brush...just make sure its kerosene...some will sell.u turpentine coz it looks n smells the same but theyre not the same. lots of hardware stores dont sell this anymore n some newer, younger generation ones have never even heard of it. Can still be easily found if u look hard enough. Diesel works as well but its a little tougher to get off once ur done.

then must wash the chain with chain cleaner ?

do you mind to recommended the cleaner is safe for o-ring and x-ring please ?

I did look at ipone on shopee, but wd-40 works too? Will it damage the chain or give not enough lube to it?

Kerosene actually is the most recommended cleaner...its even the active ingredient in alot of branded chain cleaners.

Turpentine no coz its petroleum based.

So yes...use kerosene. Not turpentine. Theyre o-ring safe.
As for wd40, should be safe...but the mr diy knock off wd40 better not coz thats also petroleum based.

Lol...dunno abt that test tbh...i have doubts.

Got some have rendam orings in multiple fluids...1 guy over a year...n kerosene came out as the best condition o ring. Which ryan even mentioned in that video

Ill save my money n stick to kerosene