Surface cleaning of intake manifold block

[redwolfstudio]

Hi everyone.
I removed the intake manifold and throttle assy, removed the rubber bushings on the engine block and wondering how clean the surface needs to be before putting everything in place.
The bike has been sitting for at least 3 years and am planning on replacing all 3 bushings.
The picture below when zoomed in shows a surface that has some small scratches.
Wondering how perfect it has to be. I’m not making a show bike but one reliable daily ride.
Thanx for your help:-)
 

[The Mighty Gryphon]

Air leaks at the throttle body connections cause idle problems.  It is important that there are no cracks in the rubber bushings that connect the throttle bodies to the air box.  The cracks are usually found where the clamps grip the bushing.

The other leakage occurs at the base of the plastic mount that attaches the throttle body to the cylinder head.  Some owners have had good luck with adding a very light smear of silicone sealer to help make a good seal. 

[redwolfstudio]

That’s interesting. So there are silicone sealant that can take high temperature?
Many thanx for your input:-)

[The Mighty Gryphon]

That is just the intake manifold.  The temperature there only gets to about 90-95 degrees C at most.  It's the exhaust manifold where the high temperatures are.

As long as you use a good grade of silicone sealant you should be okay.  And remember that you only need a light smear.  If you see any of it squeeze out you have used too much. 

Also, don't torque the screws down too soon.  Just enough to make contact between the bushing and the cylinder head, a little more than finger tight.  Wait over night, and then torque the screws down after the sealant has cured.

[redwolfstudio]

Thank you, that is great help!
Tomorrow I start:-)
Many thanx!

[rbm]

Biltema, Artnr. 36-1775 Packningssilikon, Högtemperatur

[redwolfstudio]

Awesome! Thank you very much! :-))