92 Rm80

[454sss]

I just bought a 92 RM80 and will be pulling the engine for some head work. One question though - On the very front of the engine that faces the front forks, there is a square box section (I think this is where the valve reed is?), and a nipple that looks like it should have a decent size hose or small tube attached. I'm not sure what (if anything) should be attached to this, but I don't see any loose hoses and not sure how to proceed. Any words of wisdom from those with experience appreciated. Image attached.

Paul

 

[helio lucas]

that is the exhaust valve. the reeds are located between the carb and the cylinder.

a exhaust valve (or power valve) closes the exhaust port on low rpm to gave a boost on the low end.
that nipple should have a pipe attached to when the valve get full of black oil it could pour it below the bike. also serves to not let debris, dust and water to the valve...

 

[454sss]

That answers it, thanks for your help!

Paul