Should I adjust my PSS seal?

[Gixer]

I had a PSS seal fitted a while ago and have always had a small leak which I'm wondering if I should bother doing anything with. At rest its fine but when the engine is working hard I get a small amount of water past the seal. It not a problem, more of an annoyance.
I'm assuming that the pressure on the engine mounts when pushing the boat is lowering the pressure on the seal and causing water to mist past. I've got an old 1GM10 which I know vibrates being single cylinder. The manual says you can increase the pressure on the bellows by 1/2in. I've never adjusted the PSS so am a little nervous...
Question is, should I bother or am I just going to increase the wear on the PSS seal for no real benefit?
I'm also wondering of my engine mounts might need looking at, I believe they are original 1990's.
Any thoughts?

 

[Stemar]

IIRC, adjustment is pretty simple, so I reckon it's worth a try.

Again, from memory, the rotor has two sets of grub screws. For each, remove one grub screw to get access to the one below. Slacken this one, and it should be free to move, but there's an O ring that seals it to the shaft, so it'll probably need a bit of persuasion.

Details here

 

[vyv_cox]

It is very easy to check that the compression is correct. Simply remove the grub screws, there should be two per threaded hole, pull the rotor forward until the faces separate, push aft until they just touch. Then mark the shaft with a pencil at the forward edge of the rotor and push it aft by the distance given for your installation. Replace the grub screws. In theory you should replace the inner ones so that a new hardened tip can engage with the shaft but I found no obvious rounding or deformation of the tips on mine and re-used them.

 

[Gixer]

Thanks guys, I get nervous doing anything with the stern gland and just need that bit of confidence. I'll buy some new screws just in case, they are not too expensive in the grand scheme of things.

 

[Lightwave395]

I had a PSS seal on my previous boat for a couple of years, it always leaked a little which I found a bit frustrating.

The leak was eventually fixed by adding a 90 deg elbow to the last piece of water vent pipe - the braided plastic pipe was too stiff meaning the small amount of operating movement of the engine (3ym30) caused the rotor compression to ease enough to allow a dribble of water to weep out.

I eventually had the carbon rotor refaced as you could see the wear was very slightly eccentric - caused it seems by the pipe which was bent at 90 deg to fit the rotor spigot.

Might sound unlikely at first but you can better see how tight the angle was and what I'm trying to describe in the picture:

 

[fredrussell]

Mine has always leaked a bit. New engine mounts, engine aligned - still leaks. I’m going to try Lightwave’s suggestion

 

[IanCC]

Thanks guys, I get nervous doing anything with the stern gland and just need that bit of confidence. I'll buy some new screws just in case, they are not too expensive in the grand scheme of things.

You may, as i did, find it very hard to compress. Then build a jig with wood and threaded bar to compress. Also take real care not to scratch internal face of ss bush. Easy done, when sliding on and off shaft.

I found the uk pss seal guy incredibly helpful. But I see that pss is no longer part of pyi so things may have changed.

A crucial piece of info he gave me was that the seal doesn't rely on compression but surface tension. I couldn't compress mine the recommended amount even with jig. He said no problem, and it isn't. It shouldn't leak a drop.

I found it very difficult to get the rubber gaiter/spring to sit straight on the stern tube so it didn't touch the shaft, prior to compression. All the glass bonding in the tube meant the stern tube isn't a nice clean pretty thing on my boat.

 

[pcatterall]

I put a couple of ss jubilee clips just 10mm behind the plate. it gives me confidence that the plate is not creeping backwards and is an aid to being able to tighten it up a few mm if required. I found I could tighten and hold the plate with one hand using a big screwdriver as a lever and tighten the screws with the other.

 

[greeny]

Thanks guys, I get nervous doing anything with the stern gland and just need that bit of confidence. I'll buy some new screws just in case, they are not too expensive in the grand scheme of things.

From memory I think they are an odd size. May even be imperial. Not 100% sure but seem to remember issues with them from years ago. Might be wrong though.