Search results

  1. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    Agreed wonder if there is a vacuum leak at carb base. would try shooting starting fluid at base of carb to see if rpm changes
  2. Scott06

    Pistons on Ford 302 / Mercruiser 188

    65 GTO Bought it years ago..1990. Had a 65 LeMans which I never should have sold, all I wanted after that was a GTO…
  3. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    At idle nothing should be dripping out of the venturis. The only fuel flow is below the throttle plates in idle circuit holes. Either bad needle and seat /float, incorrectly set float level, or too much fuel pressure. Since you had same issue with both carbs might lean towards fuel pressure...
  4. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    not sure what it is? I assume carbon removal from rings. Did that with mercruiser power tune and seafoam soak. Had less carbon coming out than when I have used it previously I think root cause was it was assembled by an 18 yr old idiot that I see in the Mirror
  5. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    I thought his valve train video showed relatively even lift on all 8 . Of course I look at more threads than centerfolds in my younger days could be mixing them up…
  6. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    Chinesium... to the OP if you shut the idle screws all the way down and it still runs gas may be overflowing the float bowl would look down the bores during idle. This assume you are at a normal idle and not into the transition slots like idling at 1000 rpm. No he did the leakdown which showed...
  7. Scott06

    For those thinking about an engine swap...

    At least you have some attachment to it, assume it has been in the family? Had a similar experience with my grandfathers boat ( 1966 ish Penn Yan) that he gave my brother and I after he paid $1800 to have the outdrive rebuilt ( this was in early 90's). He said you guys can have the boat but if...
  8. Scott06

    For those thinking about an engine swap...

    did a repower when I got my new boat. Old one had a 3.0 it was louder than my new one with a 5.0 previous owner cracked the 4.3 so I swapped in 5.0 because that is the biggest engine that model was offered. it’s unfortunate but your experince buying a used engine is typical. Unless you know...
  9. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    Agreed to OP when you turn the idle screws in and out you should hear idle quality change and get to a point where it stumbles both lean and also when really rich. If very little changes when you turn the mix screws several turns in and out, your idle circuit is plugged or there is no fuel in...
  10. Scott06

    283 stalls when engine cover closed

    What do the plugs look like and is there gas in the carb after it stalls? When it dies reopen the hatch and pump throttle to see if accel pump squirts gas. What does it take to restart after it dies?
  11. Scott06

    Verify I have found all drain points

    There are five places on the block, I think you have most of them. they may have hoses hooked up in your case. Yes I would rip off the single point drain and put individual plugs in The drain points are - One on each oil pan rail One under each exhaust manifold The J hose on the circulating...
  12. Scott06

    2013 Mercruiser 3.0 MPI (engine rebuild)

    The con is making sure it fits and making sure you have all the pieces. As mentioned the engine harness connects to the boat harness via a 10 pin plug. You just need to have a 4.3 hareness. By far the easiest way to do this is get a complete tear out so you have the wye pipe exhaust manifolds...
  13. Scott06

    Exhaust Bellow

    Yes the exhaust bellow is just below the u joint bellows. Absolutely no issue if it it’s torn or not there. It is open to the water at the propeller. Might be a little louder exhaust note that’s all.
  14. Scott06

    Pistons on Ford 302 / Mercruiser 188

    If you can get a scope camera put it in the spark plug holes You may find an over bore size and piston part number in the piston face. recently I was looking at buying a Pontiac V8 for my GTO, it was previously rebuilt, had seller take pics of the piston tops, and it revealed a part number for a...
  15. Scott06

    Pistons on Ford 302 / Mercruiser 188

    I would think this was a recent rebuild prior to being put away given how carbon less it looks especially on the pistons. Not sure if ford painted them blue then delivered them to merc or if you have a 302 from any vintage in the last 50 years...
  16. Scott06

    Motor knocking. Mercruiser 3.0 alpha 1

    Good point about the fuel pump. That is probably the most likely.
  17. Scott06

    Mercruiser Vacuum Gauge

    Depth might be useful. You can live without the trim and speedo....
  18. Scott06

    Motor knocking. Mercruiser 3.0 alpha 1

    They are not the quietest engine around. I think it is coming from the front but would also pull the drive to rule out drive gimbal etc. Also run it without the belt on to see if the water pump is bad. Im thinking the noise may be valvetrain or timing gear related. Might look to see if there...
  19. Scott06

    Need ideas on problem with 5.7L Mercruiser shutting down

    If it didn't turn over I would suspect you dropped 12v to that engine would start with cleaning and tighten both positive and negative battery connections. IF it happens again try and jump the starter solenoid to confirm if issue is wiring up to helm or is in engine harness. Would also remove...
  20. Scott06

    1986 Mercruiser 470/170hp/3.7L Carb backfire, low vacuum, other weird issues

    I would look at the rubbing block on dist to see if there is uneven wear. would try another set of points and condenser to see if that is why the dwell is so inconsistent. Have never seen a dwell bounce that much.
View older results
Top