sean.deangelis
Seaman Apprentice
- Joined
- Jan 25, 2013
- Messages
- 33
I'm going to try and keep this a brief as possible but requires some backstory. Engine serial number D608856, outdrive serial number D634245, 380 hours. My boat is a 1991 Baja 208 Islander.
The fuel pump died over the last 2-3 outings of the season and upon taking it apart I found that the fake "cam lobe" on the back side of the raw water/fuel pump assembly was worn out. My boat has the fuel pump mounted to the raw water pump and pulley assembly, not the block.
Replaced the failed complete assembly but I did not think to disassemble the new pump and check that an OEM style impeller was used. Big mistake. Got the boat out and all was good for about 15-20 minutes until I tried a short sprint at WOT. Took me a minute to realize but after that run it started overheating. Looked at the gauges again and temp was up to 240 degrees. Stopped the boat and waited for things to cool, opened the engine hatch. Block seemed fine, no steam anywhere. But my boat has captains choice exhaust which was open and I could see and hear the rubber exhaust tubes melting at the mixing elbows and down pipes.
Assumed something was up with the impeller and I keep a spare in the boat so I removed the impeller housing and sure enough rather than a metal "center hub" on the impeller what came with the new pump it was a plastic one that had rounded off. Meaning where the OEM metal ones have stainless steel hub that is "D" shaped to match the shaft, this one had a plastic hub that was now perfectly round and the shaft was not spinning it.
Threw in the spare impeller, fired the boat up, temps went to normal, did a WOT run again no issues and threw the boat back on the trailer.
Now here is the weird part. When I initially started the boat after replacing the impeller the idle was a bit high, like 850, where its typically like 650 warm. When I got back to the dock and took the boat out of gear it was about 1200. Putting the boat on the trailer it was 1200 in neutral as well and about 850 in gear.
It was getting late and I was whooped or I would have checked a few things first but since Saturday I'm going through my head as to what would be causing the high idle. Did I burn some carbon off that has been accumulating over years? Did I get the spark arrestor hot enough to slef-clean (it was admittedly filthy, though I had run the boat without it on the muffs while tuning the carb 2 months ago and it did not idle high). Or is there something more catastrophic that might have happened that I need to check for?
In any case if you all could give me an idea what to check for or in the unlikely even anyone has had something similar happen please let me know. Cheers.
Edit: plugs, cap, wires, rotor, coil, fuel filter are 1 month old, 2 outings on them, less than 10 hours. Carb is either a 4 barrel marine quadrajet or a dead ringer for a 4 barrel marine quadrajet (no vacuum ports for distributer advance or similar so I'm nearly certain its a proper marine carb) looks like a 750. It does NOT have the cylindrical screen type filter in the carb body at the end of the fuel line though. Which makes me think its aftermarket.
The fuel pump died over the last 2-3 outings of the season and upon taking it apart I found that the fake "cam lobe" on the back side of the raw water/fuel pump assembly was worn out. My boat has the fuel pump mounted to the raw water pump and pulley assembly, not the block.
Replaced the failed complete assembly but I did not think to disassemble the new pump and check that an OEM style impeller was used. Big mistake. Got the boat out and all was good for about 15-20 minutes until I tried a short sprint at WOT. Took me a minute to realize but after that run it started overheating. Looked at the gauges again and temp was up to 240 degrees. Stopped the boat and waited for things to cool, opened the engine hatch. Block seemed fine, no steam anywhere. But my boat has captains choice exhaust which was open and I could see and hear the rubber exhaust tubes melting at the mixing elbows and down pipes.
Assumed something was up with the impeller and I keep a spare in the boat so I removed the impeller housing and sure enough rather than a metal "center hub" on the impeller what came with the new pump it was a plastic one that had rounded off. Meaning where the OEM metal ones have stainless steel hub that is "D" shaped to match the shaft, this one had a plastic hub that was now perfectly round and the shaft was not spinning it.
Threw in the spare impeller, fired the boat up, temps went to normal, did a WOT run again no issues and threw the boat back on the trailer.
Now here is the weird part. When I initially started the boat after replacing the impeller the idle was a bit high, like 850, where its typically like 650 warm. When I got back to the dock and took the boat out of gear it was about 1200. Putting the boat on the trailer it was 1200 in neutral as well and about 850 in gear.
It was getting late and I was whooped or I would have checked a few things first but since Saturday I'm going through my head as to what would be causing the high idle. Did I burn some carbon off that has been accumulating over years? Did I get the spark arrestor hot enough to slef-clean (it was admittedly filthy, though I had run the boat without it on the muffs while tuning the carb 2 months ago and it did not idle high). Or is there something more catastrophic that might have happened that I need to check for?
In any case if you all could give me an idea what to check for or in the unlikely even anyone has had something similar happen please let me know. Cheers.
Edit: plugs, cap, wires, rotor, coil, fuel filter are 1 month old, 2 outings on them, less than 10 hours. Carb is either a 4 barrel marine quadrajet or a dead ringer for a 4 barrel marine quadrajet (no vacuum ports for distributer advance or similar so I'm nearly certain its a proper marine carb) looks like a 750. It does NOT have the cylindrical screen type filter in the carb body at the end of the fuel line though. Which makes me think its aftermarket.
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