R-21 water strainer.

[REO6205]

When my engine...3YM30...is running I can see air bubbles, very small and frothy, in the clear part of the strainer. The exhaust water discharge volume looks good and there's no over-heat warning. Are the air bubbles normal or should I be looking for an air leak somewhere in the strainer?
I took the strainer apart and cleaned the screen. How tight should the screw-on clear piece be when it goes back together.
One thing I'm finding out about owning my own boat is how little I really know about a lot of things. 😀 The days of having an engineer to take care of the mechanical stuff are long gone. Now I'm the engineer. :roll:
Thanks for the advice. This is a great forum.

 

[SGIDAVE]

When my engine...3YM30...is running I can see air bubbles, very small and frothy, in the clear part of the strainer. The exhaust water discharge volume looks good and there's no over-heat warning. Are the air bubbles normal or should I be looking for an air leak somewhere in the strainer?
I took the strainer apart and cleaned the screen. How tight should the screw-on clear piece be when it goes back together.
One thing I'm finding out about owning my own boat is how little I really know about a lot of things. 😀 The days of having an engineer to take care of the mechanical stuff are long gone. Now I'm the engineer. :roll:
Thanks for the advice. This is a great forum.

Hello REO,

I commonly see bubbles in my raw water straining especially at higher rpm's as when underway. I have a Vetus raw water strainer which has a large clear plastic cap. LIke this

The cap has a thick O-ring embedded it a groove; hand tightening is all that's necessary, but you (I) must ensure it is on straight and not cross threadded. Your strainer is probably similar except that the cup with the 'screen' is the removable part. Anyway, hand tight is good enough.

Then go around with a small ratchet/socket combo to tighten all your raw water hose clamps - heck, might as well snug up ALL the hose clamps while you're at it. Also ensure the raw water pump cover screws are tight (again, a wrench works better than a flat screw driver. And if you haven't removed the raw water cover to ensure the O-ring is properly seated in it's groove, do that as it could be a source of air entrainment into your cooling water flow. A few dabs of water soluble lubricant or plumbers grease will hold the o-ring in place while you secure the plate .

If you still see bubbles and the engine and exhaust are all good... I attribute it to turbulence.

dave