It is a FOUR CYLINDER FOUR STOKE engine.
Unless the flywheel has been bolted on in the wrong position (which I think is not possible) then
the timing hole in the flywheel WILL set cylinders 1 and 4 at the top, BUT it could be "firing" on either 1 or 4. Once you have this set and the pin in place, use a lump of chalk to mark the crankshaft pulley on its top edge so you can see it coming round to the top the next time you turn it. It is useful to know when it approaches TDC.
So, you take the rocker cover off ..... and you rotate the engine again watching the rockers on NUMBER FOUR cylinder - the last two rockers at the back of the engine. As your chalk mark comes to the top either the next time or the one after (it MUST be one of them) you will see the LAST rocker letting the valve UP, and immediately the second last rocker shoving its valve DOWN. This means that Number ONE cylinder is close to top dead centre on a FIRING stroke.
Now pin the flywheel through the hole in the housing by wiggling the engine over just enough to engage the pin.
Then do the rest of the timing from there.
OK?
CharlesY