Recent content by Harkonnen

  1. H

    J115PLSOR cylinder bank temp difference

    Yep. Replacing the head O-rings, thermostats, thermostat seals, springs, and properly resealing the cylinder heads appears to have resolved the temperature asymmetry (tested on water), oil loogies, hard starting, and excessive smoke. Which, unfortunately, does not speak particularly well of the...
  2. H

    J115PLSOR cylinder bank temp difference

    No kidding.
  3. H

    J115PLSOR cylinder bank temp difference

    Here come ugly pics
  4. H

    J115PLSOR cylinder bank temp difference

    Post-mortem (sort of) of the incident The replacement powerhead was purchased in August 2023 from a certain marine supplier in Colorado (which shall remain unnamed for now, although I hope they recognize themselves and do the right thing). The remanufacturing - using the term rather broadly -...
  5. H

    J115PLSOR cylinder bank temp difference

    Too late for a warranty claim, but I do not think bearings are involved. If it fails, it fails. I am repowering... and re-hulling if that happens.
  6. H

    J115PLSOR cylinder bank temp difference

    I hope you're right, but this is not what you expect from a rebuilt powerhead. :(
  7. H

    J115PLSOR cylinder bank temp difference

    Yep. That's the part they apparently never read. Never replaced thermostat seals, it looks like, either.
  8. H

    J115PLSOR cylinder bank temp difference

    Silicone was mostly stuck to the heads. O-rings - no idea, but since the rebuilders put silicone where manual tells them not to - I wouldn't be surprised. I'll have to see what happens with new O-rings, thermostat seal, and thermostats/springs. I am more concerned about mayo in the cylinder...
  9. H

    J115PLSOR cylinder bank temp difference

    It's free-flowing downstream of thermostats; did not expect more than a psi anyway. I hoped to catch an obstruction that way. Found another issue, which seems to explain this problem (and a couple of others, maybe). We'll see once spares are in.
  10. H

    J115PLSOR cylinder bank temp difference

    I don't like this picture one bit. Warm SB bank. Rebuilt powerhead, seriously?
  11. H

    J115PLSOR cylinder bank temp difference

    So I rigged up a crude gauge. Pressure at the test outlets, on a hose, thermostats out, engine off, is 0.1 PSI port, 0.08 sb. Not quite what I expected, but roughly consistent with a blockage between thermostat and test outlet on sb (warmer) side. Off with its head!
  12. H

    J115PLSOR cylinder bank temp difference

    I like the idea, but I suspect it may not be that simple. The springs are fairly new - they came with the replacement powerhead - and even with the thermostats removed entirely, the port bank still runs cooler. That makes me think less about the control side and more about a downstream...
  13. H

    J115PLSOR cylinder bank temp difference

    Read the manual finally ("if all else fails..."). Thermostats open at 143F+/-, idle head temp is 143F+/-, WOT 160F max. Thermostat bypass valves open around 1800 rpm. What bothers me is that port temperature drops just as thermostats are supposed to open, except that it should not matter...
  14. H

    J115PLSOR cylinder bank temp difference

    Except is is not coolant, and it is not intake/exhaust. It is port cylinder head vs starboard cylinder head, temperature of actual metal.
  15. H

    J115PLSOR cylinder bank temp difference

    Ran into an interesting case, 2005 J115PLSOR, 60 degree V-4 2-stroke looper, aftermarket cylinder head gauge showing temps separately for port and starboard. At WOT, port bank runs about 30F cooler (120 vs. 150F). Has anyone seen this? What I know so far: 1. Probably real - heat cam confirms...
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