Null


fstdraw

  • Karma: +0/-0
Pump/engine very slow to prime w/H2O
« on: July 29, 2019, 05:36:39 pm »
'92 Commander, 19 footer, 454, Berkeley 12JE, OT headers.
Lately I've been having a real problem with water getting thru the engine before the temp. gauge pegs hot.
What can possibly cause this? I can find no restriction anywhere in the system. The only thing I've not
done is try to clear out the engine water jackets. A couple of times steam has even shot out the water dump
hole on the side of the boat! This is crap for a sweet running boat like this.

A bit of help if you can, thank you.
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

Jeff@reliablesvc.com

  • Karma: +6/-0
Re: Pump/engine very slow to prime w/H2O
« Reply #1 on: July 29, 2019, 11:41:31 pm »
Only time I have ever blown steam out of the water dump was due to weeds stuck at intake grate. Maybe
Clogged somewhere down the line. Do you have a gate valve from pump to headers.


Sent from my iPhone using SoCal Jet Boats
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

Flusher

  • Karma: +84/-0
Re: Pump/engine very slow to prime w/H2O
« Reply #2 on: July 30, 2019, 05:21:56 am »
Where is your temp gauge sensor located?

Do you have a thermostat?  You shouldn't have one!  What you are describing really sounds like there might be a thermostat installed.

Do you have a gate valve on the cooling port of the jet?  Or a ball valve?  Is it open?

Do you have a pressure relief bypass?  Is it functioning properly?  I'm not a fan of these because they deprive the engine of water.  They also get lodged open with debris, starving the engine all the time.

What size are your cooling lines?

Are any of the lines pinched under the oil pan?

How are your cooling lines routed?  Basically, you should have something similar to the following routing:

Jet pump cooling port => tee => water pump ports on block => through the block, front to back => through the heads, back to front => from the front of the intake manifold overboard.

It should be pretty easy to pull the cooling line off at the jet and connect a garden hose.  It should only take a few seconds before you see water flowing out of your overboard dump.

If everything seems fine until this point, you would need to pull the bowl and check for obstructions to the cooling port.  I have seen an instance where the wear ring insulator started pushing out and would cover the cooling port.  This would only restrict flow in one direction, so blowing air or water back through the lines didn't reveal anything.
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party
"I want to roll with my brother Joe" - Joe Bateman - January 29, 1950 ~ November 27, 2013

perryb

  • Karma: +3/-0
Re: Pump/engine very slow to prime w/H2O
« Reply #3 on: July 30, 2019, 04:50:57 pm »
A thermostat is fine if you have it installed correctly with a by-pass kit, like the Rex system ( I think they're sold through Eddie Marine now). Just don't go over 160 T-stat. I put one on my BBC/Berk years ago and wouldn't be without it. It runs SO much better in cold water. The only thing I suggest however, is to drill a second 5/16" hole in the by-pass plate. That's what provides block circulation and exhaust cooling while the stat is closed and block pressure is down (low RPM).
« Last Edit: July 30, 2019, 04:55:24 pm by perryb »
  • Like
    Dislike
    Love
    HaHa
    Angry
    Surprise
    Sad
    Party

 


Null

SMFPacks CMS 1.0.3 © 2023