Merc 575SC motors..
02-20-2008, 03:38 PM
#11
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02-20-2008, 03:43 PM
#12
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02-20-2008, 03:51 PM
#13
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That's the way it came.
They're great engines, their neighbors that
live behind them ( the XR drives)
haven't been as maintenance free though
but, I think I have that issue worked out.
They've been better than the HP500's I had in my last
boat.
02-20-2008, 04:21 PM
#15
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02-21-2008, 06:48 AM
#16
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Location: Cincinnati, OH
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I have a pair in my 2002 35' Fountain. I love the motors; just make sure you follow everyone's guidelines above. I agree with the leak down test and head gasket replacement. I blew a head gasket at 281 hours and lunched the motor because I hadn't done a leak down test.
The blowers need to be rebuilt every 150-200 hours. I always had mine serviced religiously but at about 230 hours one went south, the rotors collided and I ruined. In case no one has told you, you can't get parts for them. I had to drop $3500 for a rebuilt one.
As far as squeezing HP out of them…stock they are absolutely perfect. They idle great and I had zero problems besides the lack of knowledge I had when it came to the head gaskets and blowers. However, I'm told you are limited to what the injection system will handle. I put intercoolers on my boat, which raised my HP to about 650 and I was told anything above that would necessitate modifying the fuel system and lower my reliability.
I would own another pair in a heartbeat. I feel the issues I had were due to my own ignorance.
Hope this helps.
The blowers need to be rebuilt every 150-200 hours. I always had mine serviced religiously but at about 230 hours one went south, the rotors collided and I ruined. In case no one has told you, you can't get parts for them. I had to drop $3500 for a rebuilt one.
As far as squeezing HP out of them…stock they are absolutely perfect. They idle great and I had zero problems besides the lack of knowledge I had when it came to the head gaskets and blowers. However, I'm told you are limited to what the injection system will handle. I put intercoolers on my boat, which raised my HP to about 650 and I was told anything above that would necessitate modifying the fuel system and lower my reliability.
I would own another pair in a heartbeat. I feel the issues I had were due to my own ignorance.
Hope this helps.
02-21-2008, 10:55 AM
#17
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I have a pair in my 2002 35' Fountain. I love the motors; just make sure you follow everyone's guidelines above. I agree with the leak down test and head gasket replacement. I blew a head gasket at 281 hours and lunched the motor because I hadn't done a leak down test.
The blowers need to be rebuilt every 150-200 hours. I always had mine serviced religiously but at about 230 hours one went south, the rotors collided and I ruined. In case no one has told you, you can't get parts for them. I had to drop $3500 for a rebuilt one.
As far as squeezing HP out of them…stock they are absolutely perfect. They idle great and I had zero problems besides the lack of knowledge I had when it came to the head gaskets and blowers. However, I'm told you are limited to what the injection system will handle. I put intercoolers on my boat, which raised my HP to about 650 and I was told anything above that would necessitate modifying the fuel system and lower my reliability.
I would own another pair in a heartbeat. I feel the issues I had were due to my own ignorance.
Hope this helps.
The blowers need to be rebuilt every 150-200 hours. I always had mine serviced religiously but at about 230 hours one went south, the rotors collided and I ruined. In case no one has told you, you can't get parts for them. I had to drop $3500 for a rebuilt one.
As far as squeezing HP out of them…stock they are absolutely perfect. They idle great and I had zero problems besides the lack of knowledge I had when it came to the head gaskets and blowers. However, I'm told you are limited to what the injection system will handle. I put intercoolers on my boat, which raised my HP to about 650 and I was told anything above that would necessitate modifying the fuel system and lower my reliability.
I would own another pair in a heartbeat. I feel the issues I had were due to my own ignorance.
Hope this helps.
02-21-2008, 11:20 AM
#18
Banned
The engines are set up so rich from Mercury, that yes the factory fuel system worked just fine on the 725-750 HP range. That is real about the limit with the induction system. I put the emphasis on making more power through cylinder heads, camshaft design, and compression rather than trying to drive the supercharger harder. We also went to The Blower Shop 250 superchargers. We also focused on many upgrades to the oiling system : Canton power pans 10 qt., better oil lines, any small restrictions in oiling system such as at the oil filter remote inlet, and fitting size.
