Search results

  1. Scott06

    1981 120 mercruiser rough idle

    not that it matters but the Iron Duke engine is a 151 CID Pontiac engine from the 80's, the marine 2.5 are Chevy based 153 CID engines that debuted in the chevy II in 1962, which was later made into the 3.0 marine and industrial engine. Good news is if you do need a new engine you could swap...
  2. Scott06

    Tinkering on the 4.3l this winter...

    25 would make sense as the 4.3 2 bbl is rated at 190 hp, the reman 4.3 with 4 bbl webber eddy is rated 225. I had heard somewhere on here that it takes 10 hp per 1 mph but can only assume the hull has something to say about it. I found the midrange throttle response on the 4 bbl to be way...
  3. Scott06

    I/O (Sterndrive) Conversion to Outboards

    A lot of tire kickers? I just went through selling on of our cars on marketplace, older vehicle for not much money, go so sick of it I gave it to a friends son who just totaled his car on a deer.
  4. Scott06

    3.0L mercruiser compression

    worth doing as in dash tachs tend to drift over time. if its off you may be hitting correct WOT rpm already.
  5. Scott06

    3.0L mercruiser compression

    Again find a different mechanic. Ask them to show you the published compression numbers in the mercruiser manual, it’s 150 psi… please do not spend any more money with these guys have they verified your tach against a shop tach ?
  6. Scott06

    3.0L mercruiser compression

    100% 150 is new , get a different mechanic. 3.0 is a great motor for economy of ownership and reliability, not speed. Yes you should be able to get it to 4600-4800 rpm but that is probably prop related. When I had a 3.0 I ran a 16” prop for skiing etc , may need to drop in pitch.
  7. Scott06

    Valve Lubricant

    Looks like lead substitute they recommended when leaded went away , decades ago… that part number and the superseded part numbers are NLA. A1996 will have hardened valve seats from the factory so not sure if you are using the correct manual for your engine
  8. Scott06

    2005 Mercruiser 5.0L MPI (bravo 3) suddenly started overheating

    my merc with raw water cooling (160 thermostat) generally indicates 170 on the gauge as well.
  9. Scott06

    MCM 7.4 oil

    was thinking bearing clearances.
  10. Scott06

    outdrive question

    Agreed hold it on with a rope or bungee.
  11. Scott06

    Dark colored drive shaft and black looking grease

    I usually use Lucas red N Tacky and it always comes out black. The grease you are using now may not be the same formulation despite the product being the same label, also yo may have gotten more hours in. As long as the alignment is good and keep it greased it will last decades.
  12. Scott06

    MCM 7.4 oil

    of course not but no reason to get jerked around unnecessarily and pay 2x. I have used rotella, QS 25-40 , the merc racing 20-50 and settled on mobil 1 15-50. It seems to hold hot oil pressure on long higher rpm runs better than the rotella or QS25-40. Its half the cost of the Merc 20-50. I...
  13. Scott06

    MCM 7.4 oil

    If you google it it comes out around 800 which is generally considered too low for flat tapped cams. You could add a zddp additive. this is why the rotella T4 is reccomended. A lot of guys on the classic car forums I’m on use it as well For same reason. yours would have e been speced with...
  14. Scott06

    Stuck oil filter

    Grab the metal flap with a vice grip clamped as tight as you can get it. Use BFH to hit vice grips in counter clockwise manner. Or use drift or punch to drive the holes in the filter housing CCW
  15. Scott06

    Alpha1Gen2 gear oil leak

    if I recall correctly you will need to pull the vertical shaft and gear out and the race for the bearing above the seal to change it. If you dont have it get Mercruiser manual 14 will have all the correct sequnce to do the repair. You might as well do your input shaft seal while you are in there.
  16. Scott06

    Alpha1Gen2 gear oil leak

    you wouldn't see it in the third pic as I think you are just looking at the front side of the bellhousing. If the lower seal in the upper was leaking you'd see it in the exhaust cavity and on the water pump. at this point you need to pull the drive and pressure test. When you did the shift...
  17. Scott06

    Mercruiser 4.3L wire harness

    willing to bet that goes to mercathode or something on the transom housing - what does it connect to inside the boat? As mentioned serial numbers would help. googling mercuiser transom harness a listing like this comes up with some description below...
  18. Scott06

    Bellows Replacement Mercruiser Alpha One Gen 1

    A clymers is not worth $60 get the factory merc manual. yes the process is slightly different as Gen 2 driveshaft bellows attach somewhat differently with the internal ring vs clamp.
  19. Scott06

    Alpha One Gen 2 Shaft Seal Choice

    To do the seal you have to remove the outer race of the bearing above it. There is a rolling torque for the vertical gear and driveshaft. It is changed by changing shims Behind the bearing races. Theroretically if it all goes back in the same with same shims it should be ok. Unfortunately on a...
  20. Scott06

    Mercruiser 5 L mpi cooling system

    its not ideal as they put them there for a reason, but have had no issues with a boat where when I changed them it was obvious they had been not working for years.
Top