captain_stuck
Cadet
- Joined
- Aug 29, 2013
- Messages
- 6
Hello all, been on the site watching for quite some time, had an old account years ago which is now defunct however I need some assistance so now I'm back! Here is my plight and I hope this can get figured out sooner than later.
So the rundown is this. This past winter I purchased a new to me 1998 Trophy 2352FV from the original owner. The motor froze and cracked the block resulting in it needing a new engine when I purchased it. The stock engine was a 5.0 with a 2 barrel Mercarb on it. The Leg is an Alpha one with a 1.62 ratio with a 15 pitch Merc prop on it. I purchased a new 5.7 long block from Marine Power to put in it. The build date on the long block was this past February. I used all the parts from the 305 on the new build, risers and all looked great and showed minimal usage and wear. (The guy told me he had the 305 rebuilt approx. and only had approx 10hrs on it when it froze. Had to rebuild due to improperly flushing after salt water use and having the risers corrode and leak water into the engine resulting in a blow up) The parts were all replaced.
Moving along, the new engine was built and installed this summer. When I checked the carb it was all gummed up and the powerjet was seized in it so instead of messing around with it I just purchased a remaned Rochester 2 barrel instead. I pumped all the old fuel out and put in fresh before the initial startup. New filters all around were installed. New plugs, cap and rotor and wires, thermostat as well.
That's the engine, now the problem. The boat starts great, idles just fine and when on the muffs in neutral is runs great, quick revving and has no issue quickly climbing up to 4500 rpm. Would climb higher but I won't do that to it. Put it in the water and it is a dog. Takes a country mile to get up to speed after playing with both the trim tabs and outdrive trim and even at that I cannot get satisfactory performance out of it. It is now used in freshwater and is trailered, no slips. I cannot get more than 4000 rpm and 31mph outta her. That is tops. Average top speed is closer to 28-29mph. Speed is off GPS and the rpm are off my MAC timing light. The base timing has been set to 10 degrees at idle and I am achieving 28 degrees at 4000 rpm. Again these numbers are obtained off the timing light readout. Idle speed is right around 750-800 rpm. Shifts good, I also did a oil change in the leg. Just for kicks I put a 19 pitch prop on her just to see what it would do and I could not break 20 mph with it. I am running at about 4000' for elevation giver or take either way depending on where I am at.
I now have about 5 or 6 hours on the engine and am running out of things to try. I've talked with numerous dealers, shops and no one really seems to have any notions as to the problem. I have no idea what the performance out of the 5.0 was however as far as I am concerned that 350 should have no problem spinning that leg out and needing a steeper prop to work properly. I would like to obtain a better holeshot and believe I should be able to see top speed in the low 40's with no issue planing out. The wires and firing order have been checked and rechecked. I have not yet checked the exact fuel pressure. I need to I guess. It does have an electric pump. The throttle cables have been adjusted and set off the MERC manual as was the timing and idle while it was in the base mode with the wire grounded.
I'm open to suggestions here, I would sure like to get this running before freeze up and the warranty on the engine expires. Marine power suggested I switch to a four barrel setup which I am not opposed to however with the cost of a new manifold and carb close to $800 for an Edlebrock setup and almost $1600 for Merc stuff I would like more concrete evidence that is the issue first and will fix the problem instead of guessing. I have a hard time believing that is the problem when Merc setup thousands of boats with that carb setup. It would be nice to find a manifold/carb to try first to see if that corrects the problem first.... So, I'm open to help here guys, whatever your thinking would be great! I am away for the weekend so it may take a few days for me to respond but I surely will. If you need anymore info please ask and I will get it for ya. Thanks!
So the rundown is this. This past winter I purchased a new to me 1998 Trophy 2352FV from the original owner. The motor froze and cracked the block resulting in it needing a new engine when I purchased it. The stock engine was a 5.0 with a 2 barrel Mercarb on it. The Leg is an Alpha one with a 1.62 ratio with a 15 pitch Merc prop on it. I purchased a new 5.7 long block from Marine Power to put in it. The build date on the long block was this past February. I used all the parts from the 305 on the new build, risers and all looked great and showed minimal usage and wear. (The guy told me he had the 305 rebuilt approx. and only had approx 10hrs on it when it froze. Had to rebuild due to improperly flushing after salt water use and having the risers corrode and leak water into the engine resulting in a blow up) The parts were all replaced.
Moving along, the new engine was built and installed this summer. When I checked the carb it was all gummed up and the powerjet was seized in it so instead of messing around with it I just purchased a remaned Rochester 2 barrel instead. I pumped all the old fuel out and put in fresh before the initial startup. New filters all around were installed. New plugs, cap and rotor and wires, thermostat as well.
That's the engine, now the problem. The boat starts great, idles just fine and when on the muffs in neutral is runs great, quick revving and has no issue quickly climbing up to 4500 rpm. Would climb higher but I won't do that to it. Put it in the water and it is a dog. Takes a country mile to get up to speed after playing with both the trim tabs and outdrive trim and even at that I cannot get satisfactory performance out of it. It is now used in freshwater and is trailered, no slips. I cannot get more than 4000 rpm and 31mph outta her. That is tops. Average top speed is closer to 28-29mph. Speed is off GPS and the rpm are off my MAC timing light. The base timing has been set to 10 degrees at idle and I am achieving 28 degrees at 4000 rpm. Again these numbers are obtained off the timing light readout. Idle speed is right around 750-800 rpm. Shifts good, I also did a oil change in the leg. Just for kicks I put a 19 pitch prop on her just to see what it would do and I could not break 20 mph with it. I am running at about 4000' for elevation giver or take either way depending on where I am at.
I now have about 5 or 6 hours on the engine and am running out of things to try. I've talked with numerous dealers, shops and no one really seems to have any notions as to the problem. I have no idea what the performance out of the 5.0 was however as far as I am concerned that 350 should have no problem spinning that leg out and needing a steeper prop to work properly. I would like to obtain a better holeshot and believe I should be able to see top speed in the low 40's with no issue planing out. The wires and firing order have been checked and rechecked. I have not yet checked the exact fuel pressure. I need to I guess. It does have an electric pump. The throttle cables have been adjusted and set off the MERC manual as was the timing and idle while it was in the base mode with the wire grounded.
I'm open to suggestions here, I would sure like to get this running before freeze up and the warranty on the engine expires. Marine power suggested I switch to a four barrel setup which I am not opposed to however with the cost of a new manifold and carb close to $800 for an Edlebrock setup and almost $1600 for Merc stuff I would like more concrete evidence that is the issue first and will fix the problem instead of guessing. I have a hard time believing that is the problem when Merc setup thousands of boats with that carb setup. It would be nice to find a manifold/carb to try first to see if that corrects the problem first.... So, I'm open to help here guys, whatever your thinking would be great! I am away for the weekend so it may take a few days for me to respond but I surely will. If you need anymore info please ask and I will get it for ya. Thanks!
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