I have a Yuasa YTX7L-BS and it is clearly marked on the top with "do not open" = the sealed for life battery that can be found described in the first few pages of the Yuasa catalogue link (up to about page 5 or thereabouts).
It is clear in the catalogue pictures that it is not easy to open their sealed for life batteries; the so-called "maintenance free" batts. which still need charging - to quote them.

The catalogue also shows the much earlier design of battery that has 6 little plugs that allow access for topping up the liquid/acid content of the battery with distilled water.
Such as the YuMicron pictures.
Maybe it is one of these plugs that is leaking? And, that is not water leaking but battery acid.

Yuasa are a highly regarded brand so get another if you do decide to buy.

Their recommended charge rate for the YTX14 is 1.2 Amps, if I have read their table correctly (as below).
BATTERY TYPE CAPACITY CAPACITY DIMENSIONS - MILLIMETERS WEIGHT ACID CHARGE CCA* TERMINAL ASSEMBLY
Ah (10HR) Ah (20HR) (± 2mm) with Acid VOLUME CURRENT @ TYPE FIGURE
L W H (Kg) (Litre) (Amps) -18°C (refer to page 10)
NOTE
YTX14AH-BS (ii) 12 12.6 134 89 166 4.9 0.66 1.2 210

ps In those Yuasa pics you can see that the maintenance free batteries have no line for showing the level of battery acid, whereas the other pics show the lower/higher level of battery acid clearly.

__________________
Dave