Search results

  1. Lou C

    4.3 merc water in #5 cylinder

    #6 is the rear one on the starboard (drivers) side. do you have wet joint or dry joint exhaust? if wet joint what do the sealing surfaces of the manifolds/elbows look like? salt or fresh water? the best thing to do would have been to air pressure test the cooling system passages before...
  2. Lou C

    What's a Typical Idle Mixture Setting On A Marine Holley?

    I have a Holley 4160 that was set up specifically for the OMC/Volvo 4.3 V6 these had a metering block on the primary side (with no power valve incidentally) and a metering plate on the secondary side (no mixture screws). The primary side jets were increased in size to compensate for no power...
  3. Lou C

    Exhaust Manifold bolts

    If the comp test is good and it runs well you don't have to do a valve job till needed. Just monitor the exhaust for leaks. it is one of the most common causes of inboard engine problems. My 1988 OMC had the one piece bat wing manifolds, these had no joint to leak and I never had leaks into the...
  4. Lou C

    New style volvo bellows

    IIRC, the old style bellows for the OMC Cobra and the Volvo SX were the same part, so if its an SX you have, it might be possible to use the OMC part. However, I have not heard of that new style bellows failing on this forum or others that I frequent.
  5. Lou C

    Newer era Mercury 4 stroke cooling temperatures

    We are all a bit obsessed with details aren't we lol. When I tried the 140*F stat on mine because I had heard for "years and years" that a higher temp stat was guaranteed more or less to cause clogged up cooling passages and resultant overheating, I was obsessed with the fact that it ran at 120*...
  6. Lou C

    Engine Overheating

    Well most of these Cobras will have a P/S cooler on the back of the engine, bits from the old impeller can be in there, or lodged in the thermostat housing. I have always used OE housings and impellers and usually do not have overheating problems, normal temps are 160-175 with the 160 stat...
  7. Lou C

    Newer era Mercury 4 stroke cooling temperatures

    There is that issue (people think it’s salt dropping out of suspension but I think it’s actually calcium), and the fact that open or raw water cooling is not pressurized. Pressurizing your cooling system to 15 psi with 50/50 water/antifreeze keeps the coolant from boiling till approx 265* F. In...
  8. Lou C

    4.3 merc water in #5 cylinder

    In the pix it’s hard to say where the water could be coming in but when I had the same problem it was the 2 front cyls, #s 1&2. The Head gaskets looked ok when I took the heads off but when I removed the gaskets the fire rings on those cyls were slit around the circumference. My thought was this...
  9. Lou C

    No power under load

    Without checking fuel pressure/fuel delivery you are putting the cart before the horse.... gas tank vent anti siphon valve fuel pressure fuel volume I've been driving fuel injected cars since 1987 and haven't had to clean injectors yet.
  10. Lou C

    Wonder if I should go IO again or go OB?

    OBs have several safety advantages over I/Os that is just one….here’s others: No risk of fuel vapors in the bilge A cooling system hose failure won’t flood the bilge with seawater AND overheat the engine (this happened to me back in 2013). The issue of the bellows letting in water is actually...
  11. Lou C

    Overheat on 5.0 with SX outdrive

    Great to hear that it’s fixed and you’re back on the water! Old school American engines are easy to take apart, easy to put back together and parts are reasonably priced. Great for old school DIY guys…
  12. Lou C

    EXHAUST

    Well then you can! You now have to decide If you have enough cooling water flow to be able to install a full system (including the exhaust manifolds) or only a half system (block only).
  13. Lou C

    Exhaust Manifold bolts

    As far as how bad the rust on the valves is, a compression test will tell you if one or more are not seating, so will a backfire through the intake. If so you might need to have a valve job done. Not a big deal to pull the heads on one of these. Just a few hrs work once you get the...
  14. Lou C

    EXHAUST

    Yep, once cast iron starts corroding, you can never really stop the flaking. It corrodes differently than cast aluminum. Closed cooling is really only for a new engine or a reman one that came from an auto application where antifreeze was used in the cooling system.
  15. Lou C

    Exhaust Manifold bolts

    You want your exhaust ports to look like this (when I as changing my manifolds back in 2011, for the second time) see how they are grey in color with no rust. The rust on the cyl head is just from trapped moisture (condensation, damp climate) from the gasket. This is when I still had the old...
  16. Lou C

    No power under load

    You have to make a decision either pay the mechanic for their knowledge of modern systems or make the investment in diagnostic tools and learn yourself. If I had a modern boat for sure I’d have one of those scanners that would pay for itself in a few years. With my old boat I can use the same...
  17. Lou C

    Exhaust Manifold bolts

    With these it’s hard to see a leak path till you clean off the old gaskets. What’s important: Check the sealing surfaces of the manifolds & elbows with a straight edge & feeler gauges you want them flat & level to less than .002”. If they need to be decked you can take them to a machine shop or...
  18. Lou C

    No power under load

    In addition don’t forget simple causes of low rpm like a rusted or clogged anti siphon valve or a blocked fuel tank vent.
  19. Lou C

    3.0 mercruiser i/o

    I knew that the plastic bowl was not allowed on inboards but I thought the metal bowl was allowed….
  20. Lou C

    Exhaust Manifold bolts

    Those look like the exhaust has been leaking for quite a while. The Barr gaskets are good I installed a set 5 years ago and had to remove the manifolds to get at the steering actuator and no leaks & no rust on the exhaust ports or valves
Top