I am new to forums in general so please let me know if I'm not providing the information correctly or posting in the wrong spot. I just bought my first boat for the family to teach my daughter to ski and enjoy the outdoors. I'm unfamiliar with IO drive systems, but I'm pretty mechanical with engines in general.
I've only had the boat out 4 times. The first was to test it and check it's stability and performance. On it's first test oudrive it started perfectly and was running better than I expected after sitting for 5 years indoors. The boat idles at about 900 RPM and planed out quickly to 45mph at 5100 rpm. I remembered reading that normal rmp range for this boat is somewhere between 4200-4800rpm, so I surmised the prop may be slightly small for the boat. So I visited my dealer and he quickly told me that my 19P aluminum 3-blade prop had been reworked many times and was slightly smaller in circumference than it should be. So he recommended the same Volfo Penta prop 19P aluminum and it was actually 1.25 inches larger in circumference roughly 14.5" in diameter.
So I slapped that thing on and headed back to the lake for the second time. The Volvo Penta 5.0 FL engine (1996 Seaswirl 208 bowrunner ) ran perfectly jumping 2mph to 47 mph at WOT at 4800rpm. All was perfect.
The third time on the lake a few days later I hit some sand coming in to the dock; the prop showed some minimal paint scuffing and and one small ding in one of the blades. And here is where it all started. The boat started leaking and taking in water at the shift linkage behing the plastic housing. I smelled gear oil, however I didnt see much of a slick on the water, the motor also sounded fine but I noticed a small clicking in the motor or outdrive. So I pulled the boat on the trailer, headed home and drained the gear oil–it was completely milky. Now I wanting to know if the gear oil had been bad for a while, so I drained and put in new volvo Penta gear oil and let the boat sit over night...no leaks on the ground.
So I headed back to the lake for a 20 min quick test run with the new gear lube to see how fast the water was coming in the shift linkage. So I letting it warm up and then headed across the lake slowly climbing to WOT when I noticed something scarry. my 4800RMP was reached at 20 mph and at WOT the tach now was reaching 6000 rpm. I immediately brought it back down to 4800 and ran it up one more time to see of the tach was reading correctly; well it seemed to be it shot right back up to 6100 rpm at WOT. So I loaded it back on the trailer and checked the gear oil. After only 20 minutes on the water, the outdrive oil was completely milky again.
So my 4th of July plans on the water were botched. I've note worked on an outdrive before and wasn't quite ready to start now. So I brought in to the dealer right away and asked them to take a look at the leak and assess the 6000rpm spike.
Well the mechanic called me back this afternoon and said the leak should be no problem to fix however he has no idea why the rmp's are hitting 6K. Very disappointing to hear my certified volvo Penta marine mechanic had never heard of this before.
So I'm reaching out to all of you for some possible answers on the 6000 rpm trouble. Possibilities: 1. spun bushing out on new prop, which mechanic should have been able see or feel. 2. bad rpm tachometer on the boat 3. waterpump sucked up a pebble that's restricting flow...etc.
Roger
I've only had the boat out 4 times. The first was to test it and check it's stability and performance. On it's first test oudrive it started perfectly and was running better than I expected after sitting for 5 years indoors. The boat idles at about 900 RPM and planed out quickly to 45mph at 5100 rpm. I remembered reading that normal rmp range for this boat is somewhere between 4200-4800rpm, so I surmised the prop may be slightly small for the boat. So I visited my dealer and he quickly told me that my 19P aluminum 3-blade prop had been reworked many times and was slightly smaller in circumference than it should be. So he recommended the same Volfo Penta prop 19P aluminum and it was actually 1.25 inches larger in circumference roughly 14.5" in diameter.
So I slapped that thing on and headed back to the lake for the second time. The Volvo Penta 5.0 FL engine (1996 Seaswirl 208 bowrunner ) ran perfectly jumping 2mph to 47 mph at WOT at 4800rpm. All was perfect.
The third time on the lake a few days later I hit some sand coming in to the dock; the prop showed some minimal paint scuffing and and one small ding in one of the blades. And here is where it all started. The boat started leaking and taking in water at the shift linkage behing the plastic housing. I smelled gear oil, however I didnt see much of a slick on the water, the motor also sounded fine but I noticed a small clicking in the motor or outdrive. So I pulled the boat on the trailer, headed home and drained the gear oil–it was completely milky. Now I wanting to know if the gear oil had been bad for a while, so I drained and put in new volvo Penta gear oil and let the boat sit over night...no leaks on the ground.
So I headed back to the lake for a 20 min quick test run with the new gear lube to see how fast the water was coming in the shift linkage. So I letting it warm up and then headed across the lake slowly climbing to WOT when I noticed something scarry. my 4800RMP was reached at 20 mph and at WOT the tach now was reaching 6000 rpm. I immediately brought it back down to 4800 and ran it up one more time to see of the tach was reading correctly; well it seemed to be it shot right back up to 6100 rpm at WOT. So I loaded it back on the trailer and checked the gear oil. After only 20 minutes on the water, the outdrive oil was completely milky again.
So my 4th of July plans on the water were botched. I've note worked on an outdrive before and wasn't quite ready to start now. So I brought in to the dealer right away and asked them to take a look at the leak and assess the 6000rpm spike.
Well the mechanic called me back this afternoon and said the leak should be no problem to fix however he has no idea why the rmp's are hitting 6K. Very disappointing to hear my certified volvo Penta marine mechanic had never heard of this before.
So I'm reaching out to all of you for some possible answers on the 6000 rpm trouble. Possibilities: 1. spun bushing out on new prop, which mechanic should have been able see or feel. 2. bad rpm tachometer on the boat 3. waterpump sucked up a pebble that's restricting flow...etc.
Roger
