how can i stop this oil seepage

[Jason1]

2001 monster 900.  I pulled the side cases to paint this winter and no I have a little oil that seeps out of the oil pressure sending unit.  What can I put on the threads to stop the oil? Or do I need a new washer for it?  Thanks for any reply.  Jason

[Smokescreen]

I think it should have a very small crush washer, but you might could put #2 gasket maker on it.  Don't use #1 gasket maker as it's rather more permanent...

And for all gaskets for that matter, these are the only two sealants that matter. 

Silicone by the same maker will break down in the presence of oil or fuel.

http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_sealants/auto_Permatex_Form-A-Gasket_No_2_Sealant.htm

[Smokescreen]

By the way, when I've replaced case covers I've used #1 there because I didn't intend to need to do it again for quite some time.  So, in short, #1 is forever, #2 is for regular rebuild parts.

[Howie]

Are you sure it is not the sensor itself leaking?  Clean the area, coat with aerosol powder and go for a ride, the stain in the powder will lead to the leak.

[Slide Panda]

Are you sure it is not the sensor itself leaking?

Yep it's far from uncommon for the seal in the sender sensor to give it up and develop a weeping leak though the sender. Only fix for that is a new sender. With a 2001 bike you're about due. My 2000 started weeping a couple years back.

[Smokescreen]

Good point! I've replaced one myself! Easy to figure out though.  Brake parts cleaner and an idle on stand...

[Jason1]

I will just replace the sensor,  It does have 20,000 on it.  Where is the best place to order one?  I read in other posts around $12 but that is from Europe for an opel sensor.  I just want the best price in conus.  Thanks Jason

[Smokescreen]

check out Ducti Omaha.  They have microfiche you can order off of

[greenohawk69]

I bought a Duralast for my '97 M900...had the number 117 in it.  Around $5.  Works, no more leaking.