The 285 is the pit bull of tractors. I have 1 in service on my farm in Penna.
Its powered with a Perkins 318cid 4cyl The head gasket problem is B/S
For the life of me I can understand way you would need to replace a head gasket each yr??? That mechanic that works for you SUCKS. There is no data or any info from Perkins about head gasket trouble., Unless it was run HOT.
The Perkins 318 was used in marine apps as well because of how well made the engine is.
Also was used in military gen sets, water pumps, Tug boats and so on.
I have 4500+hrs on my 285 Never Ever any problems with head gasket.
Take care of it and it will run for ever. Do not start it cold. Use the block warmer in winter. NO STARTER FLUID EVER!!!
And don't let that guys mechanic who does a head gasket ea yr mess with it. No disrespect,But he sucks.