Mag Seal weeping grease

[Paul_from_Thornbury]

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Built my RT195 about 2 years ago, when piston failed after about 18 months and I stripped engine I noticed my mag seal was weeping grease. Took mag housing off and heated, dropped bearing out and changed all seals. Rebuilt with replacement kit.
Just doing another rebuild with my new meteor piston 6 months later after about 500 miles on new kit and noticed this outer seal is again weeping grease. When wiped its about the size of 2 garden peas worth of grease.
Got mag housing off and going to change both drive side seals. Is it worth changing the outer seal again, it's a Rolf seal.

Is this just forcing out excess grease?

[HxPaul]

Is there any chance that the grease could be there from the previous rebuild,if not check your crank for burrs where the oil seal runs.

[Warkton Tornado No.1]

IMG_0014.JPG

Built my RT195 about 2 years ago, when piston failed after about 18 months and I stripped engine I noticed my mag seal was weeping grease. Took mag housing off and heated, dropped bearing out and changed all seals. Rebuilt with replacement kit.
Just doing another rebuild with my new meteor piston 6 months later after about 500 miles on new kit and noticed this outer seal is again weeping grease. When wiped its about the size of 2 garden peas worth of grease.
Got mag housing off and going to change both drive side seals. Is it worth changing the outer seal again, it's a Rolf seal.

Is this just forcing out excess grease?

If you fit the two seals ‘correctly’, you will notice that the outer & inner seals both have the springs facing toward the crank.

This goes against my experience & training, but I admit that I still comply by doing the same.

(BTW. Seals should be lubricated on assembly & it's worth being reminded of. In addition, the surface that the lip runs on can be too rough or too smooth. Polished journals will cause seal wear!)

It would make more sense & comply with engineering convention if the spring on the outer seal faced outwards so that any pressure build up was allowed out that way. Bear with me.....

So, Innocenti must have decided that any excess pressure/grease should be exhausted toward the crank & I know that this does occur.

Since the realisation of this, some years ago, I have always tried to ensure both seals are lubricated but not excessively & try to ensure that there is no 'packing' of grease in the smaller seal/spacer area for localised pressure build. Does that make sense?

So, to my way of analysis, when there is a weep from the smaller seal that has been fitted correctly (in 'my' terms. Not meant to sound arrogant ), it indicates that either the seal has worn (by comparison with the inner seal) or that the crankshaft seal journal is undersize.

Having said all of that, it isn’t too much to worry about (IMHO!) & certainly not worth an interim rebuild if all else is alright. Think about the labyrinth that any crap would have to get past in order to get into the magneto housing & you might agree. However, if uncertain that grease remains, anybody would be wise to check.

I hope the above helps....