Jump to content


  • Content Count

  • Joined

  • Last visited


About Wingnut

  • Rank
  • Birthday 08/01/1953

Contact Methods

  • ICQ
  • Yahoo

Profile Information

  • Gender
  • Location
    Eastern Shore Maryland

Recent Profile Visitors

16,492 profile views
  1. Your outdrive is actually 2 stacked gear cases. You have input shaft seals and out put shaft seals on both. There is a oil transfer hole seal between the two half's, and a small o-ring between the drive and gimbel that seals the oil passage up to the engine mounted oil bottle. There is also an oil transfer hose between the gimbel and transom. First you need to determine where the oil is coming from, as it could be a simple fix, or much more involved. If you cannot not determine the origin, then it's time to drain the drive and do an air pressure and vacuum test. W
  2. Both, as I treat 1oz per 5 gallon in season, and 2 oz per gallon in fogging mixture, along with 8 oz Merc premium 2 cycle oil. I also store my fuel tank dead empty. W
  3. Your lower gear case has counter opposing lip seals on both it's input, and output shafts, and the upper gear case has the same units on it's output shaft. All three of these seal sets spend their life under water. One seal (the outer) has it's lip facing outward. As sea water pressure increases relative to drive internal pressure, the lip forces the sealing ring tighter around the prop shaft. The inner seal has it's lip facing inward so as drive internal pressure increases, the seal ring tension around the shaft also increases. This is important because a cold drive at idle speed only has to worry about sea water infiltration, as the external water pressure is greater. As load is applied, internal pressure rises and now the risk changes to leakage of gear oil outward. The drive is hot, engine exhaust is flowing through the leg, and friction is being generated within the drive. Pressures can reach up to over 20 psi. Now you snatch back the throttle and in an instant the entire drive is immersed in sea water, rapid quench happens and a momentary vacuum occurs. In your case, both a pressure and vacuum test are required and subject test should be done with the drive devoid of gear oil. W
  4. Been using the Sta-Bil Marine 360 for a while now on all the boats I service, and have been really impressed with how it protects fuel systems and engine internals. I've had occasion to service fuel cells, injectors, and cylinder heads and have always been able to reuse existing components. No accumulation on intake or exhaust valves, clean injectors, and no apparent wear on fuel pump internals. I won't change as I'm satisfied and if you buy quart bottles in case quantity as I do, it's pretty cheap insurance. Not very hard to tell when a boat shows up here who's owner does not use a fuel treatment. W
  5. If you trashed the upper gear set, you should expect that particulate contamination has entered the lower gear set also. I would at the very least check the lower gear set, dog clutch, and both input and output shaft bearing sets for damage. If it were me, I'd replace the entire drive and keep the lower as a spare. W
  6. Did you check for spark at the plug? Also, even though your fuel pump is running, the injectors will not fire until the ECM sees oil pressure. Your oil pressure switch may have failed. You have two, an actual sender that talks to the helm gauge, and a simple go/no go pressure switch that communicates with the ECM. Put a squirt of gasoline into the intake (about half a teaspoon) and if it starts for a few seconds, then you have a fuel delivery issue. No spark to the plugs while cranking? Then we look at ignition issues. Advance the throttle about 1/8 of it's travel and give her a try also, using the shift over-ride button. If it starts then, but will not idle, the you have likely failed the IAC. (Idle Air Control valve). W
  7. What happened. You get a new boat, and disappear from the bay. We even did Middle River fireworks, as Havre de Grace Covid'ed out.
  8. Both your raw water pump impeller and primary water seal are made from EPDM rubber. Although not suitable for oil or grease service, EPDM is the best choice for water. Even hot water as industrial steam hose is actually made from EPDM. Heat wont hurt your pump seal. I do cringe when I see people using grease to ease impeller installation though. EPDM turns to jelly over time when exposed to hydrocarbon based oils and greases. Silicone is fine, as is liquid soap, and vegetable glycerine. Oil and grease seals are typically made from Nitrile Buna-N. Looks the same but react differently to oil. W
  9. Hello again Beede. You have a strange bird indeed. I can find no reference where Merc ever installed closed loop manifolds on an I/O installation back in 1994, only inboards, and even then those applications were quite limited. Perhaps your engine cam from a donor boat that had inboards or was built after 1999. In any case, you can decide now if you wish antifreeze jacketed manifolds, or go with the more conventional sea water jacketed configuration. Same manifolds, different plumbing. Sorry I sent you down the wrong path for a time, but I have never seen closed loop manifolds on an I/O before the 1999 model offerings as the earlier heat exchanges on those tend to be smaller than their inboard counterparts, and can't handle the extra heat load. It would be interesting to know how big your supplied heat exchanger actually is. Likely you have the newer 1999 on up engine as depicted below. W http://www.marinepartsplus.com/catalog/mercruiser/serialize(value)/4.3L_CARB_ALPHA-BRAVO/884714004/13798-190 http://www.marinepartsplus.com/catalog/mercruiser/serialize(value)/4.3L_CARB_ALPHA-BRAVO/884714004/13798-160
  10. Your pump has two seal sets. The internal keeps water out of the bearing cavity. The second protects the bearing cavity form outside contamination. As you are seeing water behind the pulley, your internal seal has likely failed some time ago and your bearing are sitting in sea water. Although these are sealed bearings, the seals are more intended to keep grease in than keep water out. You need the repair kit that includes the inner seal, outer seal, driveshaft, and both bearings. Earlier models also included a locking ring that is also included in the kit. Be sure the rear impeller wear plated does not show deep sand scratches during the pump rebuild. Part number for kit below. W Mercury Mercruiser Quicksilver Oem Part # 8M0050018 Driveshaft Kit
  11. The restrictor as you refer to it is an anti-reversion plate that helps prevent water-laden exhaust gasses from back flowing into the manifold, and exhaust valve port during heavy deceleration. To test the integrity of your water to water heat exchanger, remove the closed loop cooling water lines from the exchanger shell (antifreeze side) cap the outlet, and apply a 5# air pressure to the inlet. If it leaks into the raw water side (tube side of the exchanger) then the exchanger has failed. There is no difference in part numbers between the fresh water cooled (closed loop) and raw water cooled 4.3 engine exhaust manifolds. A fresh water cooled 4.3 is a bit rare. There is no antifreeze that enters the exhaust manifolds, only raw sea water. If your antifreeze bottle is going empty, look elsewhere. W
  12. I would also pressure test the tube to shell heat ex-changer as it has raw water on the tube side, and engine coolant on the shell side. A failed tube or leaking tube sheet will allow coolant to drain into the raw water side of the system,. Simple air test will eliminate that unit as a possibility. Per Merc OEM manual #32, no engine coolant enters the jacketed exhaust manifolds or risers, only raw water. Engine coolant circulation is limited to block, heads, intake manifold, heat ex-changer, thermostat housing, and engine coolant circulation pump. Coolant entering the raw water system can only be from a failed ex-changer, cracked block, or cylinder head as you suspect. My money is on a leaking ex-changer. If you find a single tube leak, you can plug that tube (both ends) with a tapered brass plug on a 4.3 as the ex-changer is bigger than it needs to be. Two leaking tubes and it's time to find a replacement. W
  13. Is there any drive lower gear case corrosion at the intersection between the front of the prop hub ring and the drive itself? missing metal there allows exhaust gasses to sneak out and ventilate the prop resulting in greatly reduced thrust. Also, what is max achieved RPM? Could have a prop bushing slipping but I doubt it as it would have likely given up all together by now. W
  14. Same hole pattern in the transom. That's all you need if you are replacing everything. W
  15. You mentioned an engineering fix. Yes, it requires a total replacement. These drives were a thin, aluminum casting which was clad in a composite. Good in theory, but the upper gear case just flexed too much resulting in premature u-joint and gimbel bearing failure. Eventually the whole gear case would yield and end up as pieces in a peach basket. The last replacement that went through a local shop here was twins in a Formula. Factory had a partial rebate program at that time, and out of pocket cost to the owner was 32K. The special rebate "assistance" program has now ended so you would be on the hook for the whole bill. There is no direct replacement, so change out to a viable replacement requires engine removal, interior transom plate change, new transom assembly to include trim cylinders, hoses, valve body, gimbel, drive, props, rear shift cable, bellows, exhaust bellows, and labor. The only thing that is the same is the bolt pattern. If I were you I would get a current price on an Ocean-X drive installed, with props, in your current ratio before I went back to the negotiating table. Keep in mind that if you are going to these lengths, a Merc Bravo III will also bolt up so you can price shop a bit. W
  • Create New...