Anyone had the head and cylinder off their 280? Are the o-rings for the head and the base gaskets reusable?

Not worth the risk re-using them

I think you know the answer to that question!!

You always take a chance re-using a gasket, I wouldn't risk it with a head seal.

TLTEL

I should have worded that differently.What i really need to know is the size of the o-rings.I have access to anything it uses thru my work.Same with the base gasket.Some gaskets are built to be reusable made of plastic bonded to metal.

My intention is to put two base gaskets in it to make it a lot easier to kick over and start.If i knew the i.d. and depth of each o-ring groove i could preorder the o-rings.

Hi

when I did this to my 350 Gas Gas, I left the head attached to the barrel, no need for top end O rings, I made my base gaskets myself so I could try different thicknesses.

TLTEL

Hi

when I did this to my 350 Gas Gas, I left the head attached to the barrel, no need for top end O rings, I made my base gaskets myself so I could try different thicknesses.

TLTEL

Did you have to do any tuning after the extra base gasket?

Not really, I would have adjusted carb but no re-jetting. The main reason for me doing it was to increase the squish clearance as it was knocking quite bad when I got the bike, It sounded quite serious when it got hot. when I checked the squish clearance with solder wire I found there was practically no clearance and the solder was almost cut through.

Being a 350 it was (and still is) high on compression and would kick back quite violently. I cant remember the actual numbers but I used two gaskets to give slightly over the recommended clearance. Possibly 1.2mm but youre bike will be different anyway.

It is much more civilised when starting and it runs fine and doesn't knock at all know and I have been riding it regularly for over three years.

hope this helps TLTEL