Anyone no if head gaskets changed around 1991 I’ve orderd a few replacement but there all same and don’t fit there to thin and sit lower than channel there in

Are you referring to the Aire (air cooled) or the Delta (water-cooled), both are from 91?

The Cylinder head O Rings on the 91 Delta are listed in the original parts book as:

M01619115 80mm x 2.62mm 

and M01619110  125mm x 2.62mm

The Aire gasket part number is not listed in the original parts book, but it looks like a paper gasket.

Water cooled I think it’s a delta as looked at pics looks like mine with gold head and gasgas logo

Also you wouldn’t have a wording diagram and info on fork seals change I thought my bike was a 93 as it has coolant tank

 I thought `93 was the first year of case induction on the 250?

Can you post a picture of the bike so we can see exactly what you've got?

Also you wouldn’t have a wording diagram and info on fork seals change I thought my bike was a 93 as it has coolant tank

Wow, that's a rare old beast. Almost certain its a Delta, plastics would originally have been white (1990) or green/purple (1991)

Looks like a delta engine plus has other delta parts on it so pretty sure that's what it is.

Anyone tell me if head gaskets were different than 1993 model I thought was delta but has coolant tank that only came out on 93 one

The 1993 engine was completely different.

https://youtu.be/9NjnN_pZDjE

not many around? good reason for that!