How do I add oil to a Honda C 90?
The oil should be checked with the bike vertical and on level ground.
On level ground, put the bike on its side stand if you have one or alternatively, lean it up against a wall (with the kick-start side facing out) so the bike is nearly vertical .
There's a small grey plastic filler cap on the right hand side of the engine near the kick start lever. It has a dip stick attached to the underside part. Un-screw the cap, lift it out and wipe the dipstick clean with a tissue or rag.
Place the clean dipstick back in the hole but DO NOT screw it in, just rest it there on the threads. Gently pull the bike towards you until it just reaches the vertical, then let it fall back to rest against the wall or it's stand.
Lift the dipstick out and look at the oil level on the hatched area. If it is not at or near the top, top up. if you pull the bike to far and go over vertical so the bike starts to fall towards you, return the bike to rest, clean the dipstick and repeat the operation.
The C90 only holds about 600ml in total so the difference between full and needing a top-up is only a couple of hundred ml at most. Don't over-fill it...They don't like it and it strains the engine's working parts!
Due to it's small oil capacity and high revving nature, If you run with cheap oils or if the engine is worn from using cheap oils the C90 will require very regular top ups and will use it's reservoir of oil rapidly if it isn't topped up. Failure to maintain oil levels will very quickly destroy the engine!