"I have read a few similar typ
"I have read a few similar type posts in this discussion board, but want to see if anyone has anymore insight. Here is my specific info:
I bought a 1999 Chaparral Sunesta 252LE this spring from a guy who had gotten it after Hurricane Katrina from a marina and replaced the engine. The boat was never sunk, but had taken on some water (you can see the water-line back in the engine compartment). The factory engine was frozen up, so he replaced with a "ready-to-run" engine from a marine engine outfitting company specializing in re-powering boats. It is supposedly the same engine (year, size, HP, etc.) as the original one. The hours on the motor were supposedly right at 200 hours.
I got the boat from him because he bought multiple boats from the Katrina auction and only had time to really focus on one. So I bought this one. It needed some wiring replaced to the dash (which I did) and trim system replaced (which I did). The original factory aluminum prop was very dinged up, so I replaced with a SS prop of the same size & pitch (19 pitch).
Took it to the lake and it started up easily. Idled a little rough, so I adjusted the electric choke (as per the manual) and check the timing, which was incorrect. It has Thunderbolt IV ignition, so I applied the jumper wire (as per the manual) and adjusted the advance to 10 (as per the manual). At this point, the boat started easily, idled smooth as glass and ran great...up to 3300 RPM's. It accelerates great (will yank a skier up NO problem) but as you get to 3300 RPM when you give it more gas, it starts to run less smoothly and does NOT go up in RPM above the 3300 mark. This is about 28 MPH. When you back off the throttle a touch until it is where 3300 RPM's ought to be, then it smooths out and will run all day there with NO problem!
I have checked the tach with a digital technician tach and verified that the dashboard tach IS accurate. According to manufacturer info, this boat should have WOT of 4600-4800 RPM with this prop.
My first reaction was that it was a fuel delivery problem. So I replaced the low-pressure fuel pump. The fuel line from the pump to the 2-bbl carb that had been installed was NOT a factory fuel line...looked more like some kind of hydraulic hose from the ends. So I replaced that with new 3/8" fuel line. 3/8" fuel lines from gas tank to gas/water separator filter and then from filter to fuel pump looked fine. NO CHANGE IN RPM's.
So then I checked spark plug wires, & the wire from the ignition coil to the distributer. They looked a questionable, so I replaced them. NO CHANGE IN RPM's.
Could the jets in the carb be the problem? Since it runs SO well all the way up to 3300 RPM's, I just keep thinking it is NOT the carb. Am I wrong? Should I rebuild the carb?
Is the 3/8" fuel line right for a 5.7L?
The previous owner TOLD me a little bit of conflicting info about the replacement motor. there is NO serial number tag on the block. It is gone. He said it was 260HP (the same HP as the original)j but he said it was a 5.0L motor. Since it has a 2-bbl carb, I think it would only be a 220HP motor if it were a 5.0L. But the model number on the carb is for a 5.7L (according to Mercruiser info.) According to Chaparral, the boat was originally shipped with a 5.7L 260HP motor. Looking at the paint on the motor, it does NOT look like the carb was changed (paint is unbroken and unchipped anywhere around the screws and base). Maybe he just was mistaken about 5.0L vs 5.7L. But if not and he did just put the carb from a 5.7L onto a 5.0L motor, would that cause this problem?
I also do NOT know the gear ratio in the Alpha drive. How can I find out what it is? Same thing, if it was a 260HP motor and now is a 220HP motor with a specific gear ratio, then maybe the 19-pitch prop needs to be more like a 17-pitch to get the WOT that it should.
What do you think?"
"I have read a few similar type posts in this discussion board, but want to see if anyone has anymore insight. Here is my specific info:
I bought a 1999 Chaparral Sunesta 252LE this spring from a guy who had gotten it after Hurricane Katrina from a marina and replaced the engine. The boat was never sunk, but had taken on some water (you can see the water-line back in the engine compartment). The factory engine was frozen up, so he replaced with a "ready-to-run" engine from a marine engine outfitting company specializing in re-powering boats. It is supposedly the same engine (year, size, HP, etc.) as the original one. The hours on the motor were supposedly right at 200 hours.
I got the boat from him because he bought multiple boats from the Katrina auction and only had time to really focus on one. So I bought this one. It needed some wiring replaced to the dash (which I did) and trim system replaced (which I did). The original factory aluminum prop was very dinged up, so I replaced with a SS prop of the same size & pitch (19 pitch).
Took it to the lake and it started up easily. Idled a little rough, so I adjusted the electric choke (as per the manual) and check the timing, which was incorrect. It has Thunderbolt IV ignition, so I applied the jumper wire (as per the manual) and adjusted the advance to 10 (as per the manual). At this point, the boat started easily, idled smooth as glass and ran great...up to 3300 RPM's. It accelerates great (will yank a skier up NO problem) but as you get to 3300 RPM when you give it more gas, it starts to run less smoothly and does NOT go up in RPM above the 3300 mark. This is about 28 MPH. When you back off the throttle a touch until it is where 3300 RPM's ought to be, then it smooths out and will run all day there with NO problem!
I have checked the tach with a digital technician tach and verified that the dashboard tach IS accurate. According to manufacturer info, this boat should have WOT of 4600-4800 RPM with this prop.
My first reaction was that it was a fuel delivery problem. So I replaced the low-pressure fuel pump. The fuel line from the pump to the 2-bbl carb that had been installed was NOT a factory fuel line...looked more like some kind of hydraulic hose from the ends. So I replaced that with new 3/8" fuel line. 3/8" fuel lines from gas tank to gas/water separator filter and then from filter to fuel pump looked fine. NO CHANGE IN RPM's.
So then I checked spark plug wires, & the wire from the ignition coil to the distributer. They looked a questionable, so I replaced them. NO CHANGE IN RPM's.
Could the jets in the carb be the problem? Since it runs SO well all the way up to 3300 RPM's, I just keep thinking it is NOT the carb. Am I wrong? Should I rebuild the carb?
Is the 3/8" fuel line right for a 5.7L?
The previous owner TOLD me a little bit of conflicting info about the replacement motor. there is NO serial number tag on the block. It is gone. He said it was 260HP (the same HP as the original)j but he said it was a 5.0L motor. Since it has a 2-bbl carb, I think it would only be a 220HP motor if it were a 5.0L. But the model number on the carb is for a 5.7L (according to Mercruiser info.) According to Chaparral, the boat was originally shipped with a 5.7L 260HP motor. Looking at the paint on the motor, it does NOT look like the carb was changed (paint is unbroken and unchipped anywhere around the screws and base). Maybe he just was mistaken about 5.0L vs 5.7L. But if not and he did just put the carb from a 5.7L onto a 5.0L motor, would that cause this problem?
I also do NOT know the gear ratio in the Alpha drive. How can I find out what it is? Same thing, if it was a 260HP motor and now is a 220HP motor with a specific gear ratio, then maybe the 19-pitch prop needs to be more like a 17-pitch to get the WOT that it should.
What do you think?"
