I have honda forza 250. i have F problem @

moved yah out of cars to MC
cranks ok , not told
cranks and not starting is check fuses first.
125cc you meant sure, engine size TINY./
68 plate jargon means zero outside UK, are you.?
MC all have a real year.
the VIN code on all ours USA back to 1965 has year code.
I owned 1965 honda and suzuki x6 then. as a punk.
we cant see you starting it and hearing it ,at all
we can only dream it or ESP it.
and I fail.

What do you mean by "burnt"? A black sooty plug suggests the engine is running a too rich a fuel mixture.
A blistered, dry plug suggests the engine is running too hot.
There are many reasons for a burnt plug including engine overheating, wrong or loose fitting spark plugs, wrong fuel air mixture or even an old dirty air filter.
I suggest you take it to a good mechanic so they can look at the bike to see what other engine areas could be causing the issue.

Unlock cable behind number plate under the seat push it and seat unlock itself

Perhaps you should elaborate further. Is having a Forza 250 F the problem???

12 volt battery

Set mileage to main...not trip...hold down reset button...turn on ignition holding down the reset button for 3 seconds and that will clear it

yes

High mileage for a scooter will be around 60-70,000km so i think the scooter you are looking at looks pretty good if it is in good condition. The Suzuki AN250 and the Honda Forza are actually both very reliable scooters and should easily pass 70,000 km if ridden safely. if i were you i would go for the Honda Forza, i have had one for just under a year and it is in top shape and it is a joy to ride.