Greetings All,
I'm trying to troubleshoot this 3.0 LX. Just rebuilt carb. Motor starts real easy, idles great, runs great on plane off the dock (with proper warm-up). Cruises the lake fine on plane at operating temp off the dock.
Then I hang out in a bay for an hour fishing. It starts easy, and moves around at low rpm no problem.
Go to head home, and the thing starts up easy, purrs like a kitten, I let it get up to temp, then give her the beans to get back to the launch and it starts to misfire when I push the throttle. Still purrs at idle.
Managed to get out of the hole and onto plane once and it misfired slightly less but still wasn't happy. But seemed like decreased load on plane helped.
In neutral, engine revs happy to wot no problem. When its in gear it misfires. So thinking timing and ignition is OK.
To me this seems like a fuel starvation issue. How far off am I?
I had similar symptoms last time out, but more extreme. Ran great out to the spot, started misfiring on the way home. I noticed the accelerator pump had failed. So rebuilt carb, found that the retainer on accelerator pump had fallen off, thought I had the problem dead to rights. Still did a full clean and rebuild while I had it open.
I've got one of those dumb inline filters on it right now so I could see fuel flow. It was not filling up all the way. So will check filter, pickup tube and mechanical fuel pump tomorrow.
The thing I don't get is why it runs fine on the way out, then terrible on the way back. Happened the last 3 times out. Obviously there is a bit of heat soak when the engine is shut off and water pumps aren't moving new water. Are there any known heat soak type issues with the 3.0LX?
Oil looks good. No water leaks inside bilge. Don't think it's the head gasket or a cracked block.
Manifold is only 3 years old, with minimal use, flushed then drained every use, and spends winter pickled in antifreeze. Hoping not a leak in there, but feel like that would cause problems on the way out too.
Impeller and thermostat are new this season.
Fuel is fresh ethanol free 92.
I'm trying to troubleshoot this 3.0 LX. Just rebuilt carb. Motor starts real easy, idles great, runs great on plane off the dock (with proper warm-up). Cruises the lake fine on plane at operating temp off the dock.
Then I hang out in a bay for an hour fishing. It starts easy, and moves around at low rpm no problem.
Go to head home, and the thing starts up easy, purrs like a kitten, I let it get up to temp, then give her the beans to get back to the launch and it starts to misfire when I push the throttle. Still purrs at idle.
Managed to get out of the hole and onto plane once and it misfired slightly less but still wasn't happy. But seemed like decreased load on plane helped.
In neutral, engine revs happy to wot no problem. When its in gear it misfires. So thinking timing and ignition is OK.
To me this seems like a fuel starvation issue. How far off am I?
I had similar symptoms last time out, but more extreme. Ran great out to the spot, started misfiring on the way home. I noticed the accelerator pump had failed. So rebuilt carb, found that the retainer on accelerator pump had fallen off, thought I had the problem dead to rights. Still did a full clean and rebuild while I had it open.
I've got one of those dumb inline filters on it right now so I could see fuel flow. It was not filling up all the way. So will check filter, pickup tube and mechanical fuel pump tomorrow.
The thing I don't get is why it runs fine on the way out, then terrible on the way back. Happened the last 3 times out. Obviously there is a bit of heat soak when the engine is shut off and water pumps aren't moving new water. Are there any known heat soak type issues with the 3.0LX?
Oil looks good. No water leaks inside bilge. Don't think it's the head gasket or a cracked block.
Manifold is only 3 years old, with minimal use, flushed then drained every use, and spends winter pickled in antifreeze. Hoping not a leak in there, but feel like that would cause problems on the way out too.
Impeller and thermostat are new this season.
Fuel is fresh ethanol free 92.
