LakeLiving
06-20-2020, 03:01 PM
Any Mechanics out there want to take a stab at this one?
I have a 2005 Moomba Outback with an Indmar 5.7. She was missing a bit of top end speed end of last season but otherwise fine.
Before winterizing I changed the oil, put in new plugs (properly gapped), and new distributor cap. I put in the water 3 weeks ago and she barely got to 5 MPH before bogging down. It starts and idles fine and can rev it in Nuetral to 6k RPM.
My fuel pump was whining like it was starving for gas so I changed the fuel filter, then cleaned the pump, and finally replaced the pump. Still whining so I replaced the fuel line. That did the trick. Nice and quiet again but didn't help performance.
Noticed she was running hot so I put in a new (and much needed) water impeller. Running at <1700 degrees now.
I checked a few sensors (MAP, TPS, Air Intake) all good
Then did a fuel pressure test and realized my Fuel Pressure Regulator was bad. Was pushing 80lbs of pressure. Replaced it and the boat actually responded. I could now go 20 MPH but it bogs if I push the throttle any more. Then it back fires if I keep the throttle on too much.
I did have a mobile mechanic stop by early on, before I changed the fuel pump. He wanted to replace a sensor on the distributor/coil but couldn't get it off and said he was in a rush ... so he just pulled the whole distributor shaft out and took it to his shop. He came back and installed it the next day. I wonder if he F'd up my timing. So once I was able to get it to 20 MPH (with new fuel pres. reg.) I loosened the distributor cap and moved it a bit. Sure enough boat now goes 25 MPH.
Today I had another mechanic show up with a timing gun. We followed owners manual and put her into Base Timing Mode with a jumper on the DLC. Adjusted the timing to spec at 10. (it was at 8.9 from when I adjusted it by ear). It wouldn't go any higher than 10 even if we rotated the distributor a quarter turn... but we did get it to 10 and then retested and it held. He also said that if the boat has a 'Crank Position Sensor' (mine does) that the timing should be done using the alternate method using an Indmar Diacom. But that means sending her off to an Indmar dealer for 2-3 weeks.
Took her on the water to test under load: Same results :( ... Slow out of the hole, gets to 25mph and if I try to push further it just bogs and eventually backfires. I can cruise between 20-25mph without backfire. Starts and idles well. Revs to 6k RPM smoothly in neutral. Fuel pressure still looks good.
Questions
1. Is it safe to use her as a pontoon boat (slow sunset cruises, etc.) till end of season or might that cause more damage? I have friends on the lake that I can ski with. My wife just wants the boat for social activities.
2. Should I bring her to a dealer for diagnostics and to have timing done with the Diacom? (they are all scheduling 3 weeks out)
3. Should I pull my fuel injectors and send them to be cleaned/tested? (I've run 1/2 tank w/ can of Seafoam)
4. What else can/should I try at this point?
Thanks for any help/advice you may offer!
I have a 2005 Moomba Outback with an Indmar 5.7. She was missing a bit of top end speed end of last season but otherwise fine.
Before winterizing I changed the oil, put in new plugs (properly gapped), and new distributor cap. I put in the water 3 weeks ago and she barely got to 5 MPH before bogging down. It starts and idles fine and can rev it in Nuetral to 6k RPM.
My fuel pump was whining like it was starving for gas so I changed the fuel filter, then cleaned the pump, and finally replaced the pump. Still whining so I replaced the fuel line. That did the trick. Nice and quiet again but didn't help performance.
Noticed she was running hot so I put in a new (and much needed) water impeller. Running at <1700 degrees now.
I checked a few sensors (MAP, TPS, Air Intake) all good
Then did a fuel pressure test and realized my Fuel Pressure Regulator was bad. Was pushing 80lbs of pressure. Replaced it and the boat actually responded. I could now go 20 MPH but it bogs if I push the throttle any more. Then it back fires if I keep the throttle on too much.
I did have a mobile mechanic stop by early on, before I changed the fuel pump. He wanted to replace a sensor on the distributor/coil but couldn't get it off and said he was in a rush ... so he just pulled the whole distributor shaft out and took it to his shop. He came back and installed it the next day. I wonder if he F'd up my timing. So once I was able to get it to 20 MPH (with new fuel pres. reg.) I loosened the distributor cap and moved it a bit. Sure enough boat now goes 25 MPH.
Today I had another mechanic show up with a timing gun. We followed owners manual and put her into Base Timing Mode with a jumper on the DLC. Adjusted the timing to spec at 10. (it was at 8.9 from when I adjusted it by ear). It wouldn't go any higher than 10 even if we rotated the distributor a quarter turn... but we did get it to 10 and then retested and it held. He also said that if the boat has a 'Crank Position Sensor' (mine does) that the timing should be done using the alternate method using an Indmar Diacom. But that means sending her off to an Indmar dealer for 2-3 weeks.
Took her on the water to test under load: Same results :( ... Slow out of the hole, gets to 25mph and if I try to push further it just bogs and eventually backfires. I can cruise between 20-25mph without backfire. Starts and idles well. Revs to 6k RPM smoothly in neutral. Fuel pressure still looks good.
Questions
1. Is it safe to use her as a pontoon boat (slow sunset cruises, etc.) till end of season or might that cause more damage? I have friends on the lake that I can ski with. My wife just wants the boat for social activities.
2. Should I bring her to a dealer for diagnostics and to have timing done with the Diacom? (they are all scheduling 3 weeks out)
3. Should I pull my fuel injectors and send them to be cleaned/tested? (I've run 1/2 tank w/ can of Seafoam)
4. What else can/should I try at this point?
Thanks for any help/advice you may offer!