Hoplite808
Well-Known Member
- Jan 11, 2022
- 507
- Boat Info
- 1996 Sea Ray 270 Sundancer
- Engines
- Mercruiser 7.4 LX MPI EFI (Gen. V)
Been working on getting my boat to run right since January and still no joy. But I think I’m close.
Work done so far:
Rebuilt the top half of the 7.4. Rebuilt heads and new near about everything else. Compression reads within acceptable range on all 8 cylinders.
All new tune up parts. I checked the timing by inserting a jump wire in the test plug to connect A and B leads and then set idle to 1800 RPM’s with a digital tach. Then adjusted the timing to 8° BTDC.
Outdrive was just entirely replaced with a fully rebuilt one.
I took the boat out today and in neutral it revs all the way up to 4500 rpm’s. However under load it will hit a wall at 2000 rpm’s and no matter what the boat wouldn’t go faster than 9 knots.
Thought it might be old stale fuel but I ran it down to 1/8th tank and then added 25 gallons and no change. Also no signs of water in the gas when I checked the contents of the fuel separator.
I’m at a loss here. No idea what else could be wrong with it. Anyone have any ideas?
Work done so far:
Rebuilt the top half of the 7.4. Rebuilt heads and new near about everything else. Compression reads within acceptable range on all 8 cylinders.
All new tune up parts. I checked the timing by inserting a jump wire in the test plug to connect A and B leads and then set idle to 1800 RPM’s with a digital tach. Then adjusted the timing to 8° BTDC.
Outdrive was just entirely replaced with a fully rebuilt one.
I took the boat out today and in neutral it revs all the way up to 4500 rpm’s. However under load it will hit a wall at 2000 rpm’s and no matter what the boat wouldn’t go faster than 9 knots.
Thought it might be old stale fuel but I ran it down to 1/8th tank and then added 25 gallons and no change. Also no signs of water in the gas when I checked the contents of the fuel separator.
I’m at a loss here. No idea what else could be wrong with it. Anyone have any ideas?