penta newbie
Cadet
- Joined
- Jun 4, 2012
- Messages
- 12
Hello forum,
I was hoping to get a little help on how to diagnose a problem without having to put the boat back in the water. I recently bought a Glastron 225GX that had a damaged 5.0GL-PEFS with an SX 1.60M drive. I replaced the engine with a 5.7L Vortec Marine engine. I put it back together, set everything, and had it working fine. Ran through 25 hours of break in last weekend without a hitch. During this time, I did not exceed 4500 rpm and avoided WOT holeshots.
I took the boat for a 30 minute cruise down the sound on Sunday and when I got ready to return, I pushed it to WOT and then throttled back as the engine hit about 4000 rpm. Now up on plane, everything was good for about 20 seconds, and then the engine rolled back and almost died. oil pressure, alternator volts, and water temp all normal. I pulled the throttle back to idle, and the engine idled with no problem. Throttle advance in gear to 1200 rpm no problem, but it chokes and hesitates above that setting. Out of gear, the engine runs smoothly across the entire RPM Range..well 600 to 4000 or so. I don't run to 5000 unloaded.
I was lucky enough to get the engine to spool back up to 3000 and ran back to the ramp fluctuating the throttle from 3000 up to 4000 with no issues. The ride back was 25 minutes, and it maintained these settings on plane. Backing down to 2800 it runs rough again and has difficult spooling back up.... Problem area, 1200 to 2800 rpm.
Prestolite distributor system, Holley 500CFM carb (from 5.0GL)
Any ideas?
I was hoping to get a little help on how to diagnose a problem without having to put the boat back in the water. I recently bought a Glastron 225GX that had a damaged 5.0GL-PEFS with an SX 1.60M drive. I replaced the engine with a 5.7L Vortec Marine engine. I put it back together, set everything, and had it working fine. Ran through 25 hours of break in last weekend without a hitch. During this time, I did not exceed 4500 rpm and avoided WOT holeshots.
I took the boat for a 30 minute cruise down the sound on Sunday and when I got ready to return, I pushed it to WOT and then throttled back as the engine hit about 4000 rpm. Now up on plane, everything was good for about 20 seconds, and then the engine rolled back and almost died. oil pressure, alternator volts, and water temp all normal. I pulled the throttle back to idle, and the engine idled with no problem. Throttle advance in gear to 1200 rpm no problem, but it chokes and hesitates above that setting. Out of gear, the engine runs smoothly across the entire RPM Range..well 600 to 4000 or so. I don't run to 5000 unloaded.
I was lucky enough to get the engine to spool back up to 3000 and ran back to the ramp fluctuating the throttle from 3000 up to 4000 with no issues. The ride back was 25 minutes, and it maintained these settings on plane. Backing down to 2800 it runs rough again and has difficult spooling back up.... Problem area, 1200 to 2800 rpm.
Prestolite distributor system, Holley 500CFM carb (from 5.0GL)
Any ideas?
