How to: clean and polish valve guide outside surface

[TPEHAK]

Alright, the valve seats chamfers have been cut to necessary size and lapped for perfection

Now they should be better than new

No leakage at all

Everything is ready to be assembled. New valve gaskets, lapped valves and valve seats.

Since I have not found 7mm valve seal protective sleeve and James gaskets for some reason does not include protective sleeve in their "premium" gaskets set I just used vinyl tape to protect new seals while installation

And here we go, now it is time to assemble the engine back, now it should work like new, right?

 

[Cooter]

Theres a whole lot more to a new engine that just valve seals and piston rings. This should help you though. Good job!

 

[Outlaw]

Should be much bettet

 

[TPEHAK]

Probably bad valve seals is part of the reason the intake valves were under thick layer of dirt. But the exhaust valves were pretty clean.

I also found the valve seats chamfer outside diameter is bigger, than manual suggests. Manual says the outside diameter of the 46 deg valve seat chamfer should be 2 mm smaller than diameter of the valve head. But those 46 deg chamfer diameter was almost like valve diameter. Maybe this is part of the reason too the intake valves were dirty. Inappropriate valve seal allocation caused poor valve heat transition and so oil burned in the intake valve chamber.

I also created quick drawing for the valve seat geometry and found if you do 46 deg chamfer outside diameter 2 mm smaller than valve head diameter it will almost completely eliminate 60 deg chamfer, especially on the intake valve (60 deg chamfer outside diameter will be smaller than internal diameter of the valve seat). So I was confused, maybe they installed wrong size valve seats or too small valves? Or maybe there is a mistake in service manual? Anyway I just reduced 46 deg chamfer diameter less than 2 mm and set 46 deg chamfer to minimal width (1 mm), so 60 deg chamfer is still presented.

 

[TPEHAK]

OK, today I performed first test ride and noticed that fan starts working much earlier and even in cases when it was never worked before. It is pretty cold weather here today and I cruised on motorcycle at 25-30 mph and fan started working after 15 minutes I started riding right on the go which never happened before. It looks like all that carbon buildup I cleaned off the cylinder head worked like heat shield, now after I cleaned all this stuff off heat transfered much faster.

 

[Outlaw]

Oooh ma god

 

[Silverrider]

Its not rocket science, Friction creates heat. Heat creates expansion. Expansion reduces running clearances and increases friction. More friction, more heat, more expansion.