Team PCBeach
Active Member
- Oct 12, 2010
- 183
- Boat Info
- 360 Sundancer 2003, SIMRAD 3G Radar, Raymarine Autopilot
- Engines
- Twin 8.1L Horizon
Long post here, but wanted to include all information.
2003 Sundancer 360 with Merc 8.1s. 465 hours salt water both engines. Back in April/May had the boat hauled due to a vibration when on plane. This was after having the boat trucked from the Fl Panhandle to Jacksonville. Ended up having the cutlass bearings replaced, props scanned and aligned, shafts pulled and machined and engines aligned. Vibration gone and ran 3200-3400rpm for 32 mile trip back to home marina. Boat ran better than it ever has since we bought her in Aug 18. Boat then sat until this weekend due to a surgery I had. We did get to the boat and start the engines once a month, but could not run her.
Went our for the first time Saturday and could initially neither engine would go above 2200rpm when under load. No alarms. Put transmission in neutral both engines easily rev to 3600+ and sound great. Drove around for about 30 minutes going a short way with the with the current and against the current. A little improvement, PORT will come up to 3000 and STBD 3600 at WOT. Boat is lightly loaded with two adults and 100gal of fuel. Diver cleaned the hull 3 weeks ago.
The only maintenance that has been done since the perfect 32 mile trip in May was to replace the PORT IAC and the IAC mufflers in both engines. Just to make sure the mufflers were not the cause, pulled them today and did a test run. No change 3000 PORT, 3600 STBD. Put the mufflers back in.
Any suggests on a possible cause or what to look for? I am going to have the diver dive the hull early to clean again and look for any possible fouling. The only time I have had an WOT RPM issue in the past was when I had a significant fouling issue due to me being new to wet slip boating and not having a diver when we first bought the boat.
Also I am due for plugs so am going to have them replaced (mechanic always does compression check when changing plugs). I am skeptical this is the problem since my issue is in both engines and they ran great back on the last trip in May. Also, last fuel fill-up was in April and stabilizer was added at the time to both tanks.
2003 Sundancer 360 with Merc 8.1s. 465 hours salt water both engines. Back in April/May had the boat hauled due to a vibration when on plane. This was after having the boat trucked from the Fl Panhandle to Jacksonville. Ended up having the cutlass bearings replaced, props scanned and aligned, shafts pulled and machined and engines aligned. Vibration gone and ran 3200-3400rpm for 32 mile trip back to home marina. Boat ran better than it ever has since we bought her in Aug 18. Boat then sat until this weekend due to a surgery I had. We did get to the boat and start the engines once a month, but could not run her.
Went our for the first time Saturday and could initially neither engine would go above 2200rpm when under load. No alarms. Put transmission in neutral both engines easily rev to 3600+ and sound great. Drove around for about 30 minutes going a short way with the with the current and against the current. A little improvement, PORT will come up to 3000 and STBD 3600 at WOT. Boat is lightly loaded with two adults and 100gal of fuel. Diver cleaned the hull 3 weeks ago.
The only maintenance that has been done since the perfect 32 mile trip in May was to replace the PORT IAC and the IAC mufflers in both engines. Just to make sure the mufflers were not the cause, pulled them today and did a test run. No change 3000 PORT, 3600 STBD. Put the mufflers back in.
Any suggests on a possible cause or what to look for? I am going to have the diver dive the hull early to clean again and look for any possible fouling. The only time I have had an WOT RPM issue in the past was when I had a significant fouling issue due to me being new to wet slip boating and not having a diver when we first bought the boat.
Also I am due for plugs so am going to have them replaced (mechanic always does compression check when changing plugs). I am skeptical this is the problem since my issue is in both engines and they ran great back on the last trip in May. Also, last fuel fill-up was in April and stabilizer was added at the time to both tanks.