bertram31.com

Hello faithful. I hope everybody is having a good summer. Maybe somebody can help me out with a problem I’m having on my boat. When my stbd engine gets up to 1850 rpm’s my packing stops dripping and heats up. When I drop it back below 1850 it drips again. No matter how much I loosen the packing it won’t drip. Any ideas. I have 250hp Perkins in my 31. Thanks for any advice, Kurt

Kurt

Did you repower? Change the shaft logs?

Maybe at speed you are not getting enough water flow to the packing through the log.
If you changed the log and where it comes out of the hull is not the correct size it could starve the log for water.

I believe it is called Bernouilles law when this happens.

Only answer to that is, drill and tap the log and run water line off the engine or put in dripless shaft seals.

Boats going too fast for your log design, as Tony said.


Or packing is not packed right.

Old dried out packing that lost its waxy coating deteriorates and can squeeze in too tight at one extreme or let water flow too freely when not snug...little if any in between adjust ability.

New packing has old packing underneath.
New packing wrong size...have had people stuff a bunch of 1/4" in when 3/8 was needed.
The cuts where not installed in an alternating pattern, but lined up. I also like cut on a diagonal.

If boat didn't have problem before at same RPM, I'd look to packing. Its cheap stuff at around 1-$2 foot.

Update. Took stuffing box apart and cleaned the shaft. Slid shaft back and cleaned growth from the shaft that was up in the tunnel. I installed new packing and it is flowing water again. Thanks again for the advice.