Bullnose Gator Posted November 17, 2021 Author Share Posted November 17, 2021 I think you can. But you don't want the pin to come close to the stator, so any excess should probably point down - unless it'll hit something. Well, the plot thickens...as I said, it will turn over, but runs rough and I have to keep my foot on the pedal or it will stall. For no good reason I decided to flip the switch to the rear tank (that tank doesn't work, or works poorly, haven't figured out the problem yet) and it settled into what seemed to me to be a pretty normal idle and I didn't have to keep my foot on the pedal. This only lasted a couple minutes because, like I said, the rear tank doesn't send properly. I am also getting fuel coming out of the center of the carb when I give it gas, but the front fuel bowl level looked good last time I checked the sight plug. I just haven't been able to check it again because I can't keep it running long enough. So now I'm even more stumped lol Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 17, 2021 Share Posted November 17, 2021 Well, the plot thickens...as I said, it will turn over, but runs rough and I have to keep my foot on the pedal or it will stall. For no good reason I decided to flip the switch to the rear tank (that tank doesn't work, or works poorly, haven't figured out the problem yet) and it settled into what seemed to me to be a pretty normal idle and I didn't have to keep my foot on the pedal. This only lasted a couple minutes because, like I said, the rear tank doesn't send properly. I am also getting fuel coming out of the center of the carb when I give it gas, but the front fuel bowl level looked good last time I checked the sight plug. I just haven't been able to check it again because I can't keep it running long enough. So now I'm even more stumped lol Well, I think the plot just took a significant turn - away from ignition to fuel. So you probably have a carb issue. And I'll guess it is a float level or needle and seat issue. I say that because with the rear tank not supplying fuel the float level would drop as the engine uses fuel. So a too-high fuel level, which could be caused by either a too-high setting or bad needle/seat combo, would go away pretty quickly. Another issue I thought of was the power valve, but it wouldn't change with the removal of fuel pressure when you flipped the switch. So I'd rule that out, although if you are into the carb you might want to replace it anyway. Link to comment Share on other sites More sharing options...
Bullnose Gator Posted November 17, 2021 Author Share Posted November 17, 2021 Well, I think the plot just took a significant turn - away from ignition to fuel. So you probably have a carb issue. And I'll guess it is a float level or needle and seat issue. I say that because with the rear tank not supplying fuel the float level would drop as the engine uses fuel. So a too-high fuel level, which could be caused by either a too-high setting or bad needle/seat combo, would go away pretty quickly. Another issue I thought of was the power valve, but it wouldn't change with the removal of fuel pressure when you flipped the switch. So I'd rule that out, although if you are into the carb you might want to replace it anyway. that's good to hear, i think. I've only messed with the front fuel bowl so far on the carb, so I'll start with adjusting the float level again first and then read up on how to test the needle and seat operation and the pressure valve. When it's on the front tank and I'm giving it some gas, the engine runs with a chugga-chugga kind of wobble, at a consistent rhythm, does that also sound consistent with how fuel is flowing through the carb? Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 17, 2021 Share Posted November 17, 2021 that's good to hear, i think. I've only messed with the front fuel bowl so far on the carb, so I'll start with adjusting the float level again first and then read up on how to test the needle and seat operation and the pressure valve. When it's on the front tank and I'm giving it some gas, the engine runs with a chugga-chugga kind of wobble, at a consistent rhythm, does that also sound consistent with how fuel is flowing through the carb? I suspect it is the float level, and since that's the easiest thing to adjust I'd start there. It won't hurt anything to have it low. All a little low will do is to cause it to run out of fuel on hard acceleration as you wind it out in a couple of gears. Your description sounds like it is rich, and that is consistent. Link to comment Share on other sites More sharing options...
Bullnose Gator Posted December 10, 2021 Author Share Posted December 10, 2021 I suspect it is the float level, and since that's the easiest thing to adjust I'd start there. It won't hurt anything to have it low. All a little low will do is to cause it to run out of fuel on hard acceleration as you wind it out in a couple of gears. Your description sounds like it is rich, and that is consistent. I adjusted the float level up and down, no position seems to make a difference in the "chugga chugga" rough idle and it still stalls without giving it gas. I took the front fuel bowl off again and the float and needle seem to be doing what they're supposed to. It seems to run with a regular idle until the fuel bowl fills up and then it kicks into the chugga chugga stall routine, which is consistent with what happens when I switch it to the rear tank until it stalls. Any more carb troubleshooting things I can try or should I look into carb rebuild/replace options? Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 11, 2021 Share Posted December 11, 2021 I adjusted the float level up and down, no position seems to make a difference in the "chugga chugga" rough idle and it still stalls without giving it gas. I took the front fuel bowl off again and the float and needle seem to be doing what they're supposed to. It seems to run with a regular idle until the fuel bowl fills up and then it kicks into the chugga chugga stall routine, which is consistent with what happens when I switch it to the rear tank until it stalls. Any more carb troubleshooting things I can try or should I look into carb rebuild/replace options? If I understand what you are saying, that it does the same thing on the front tank as on the rear tank, then that is not what I understood before. And that suggests to me that you have a blown power valve or accelerator pump. If either of those things are bad you'll dump fuel right into the intake, and the higher the fuel level the more fuel since there is more gravitational pressure. Not "fuel pressure" as in pressure from the pump, but gravitational pressure caused by the weight of the ever-higher fuel. Link to comment Share on other sites More sharing options...
mat in tn Posted December 11, 2021 Share Posted December 11, 2021 If I understand what you are saying, that it does the same thing on the front tank as on the rear tank, then that is not what I understood before. And that suggests to me that you have a blown power valve or accelerator pump. If either of those things are bad you'll dump fuel right into the intake, and the higher the fuel level the more fuel since there is more gravitational pressure. Not "fuel pressure" as in pressure from the pump, but gravitational pressure caused by the weight of the ever-higher fuel. im assuming that this is a Holley carb based on the front fuel bowl reference. is it a replacement or a factory? more just for specific understanding really. mostly this sounds to me to be that the carb should be rebuilt thoroughly. first thought is that the needle cannot seal off the incoming fuel. if the carb has had the privilege of sitting for any length of time and ever had the chance to dry out then all rubber items are potentially dry rotted from the ethanol evaporation. Link to comment Share on other sites More sharing options...
Bullnose Gator Posted December 13, 2021 Author Share Posted December 13, 2021 If I understand what you are saying, that it does the same thing on the front tank as on the rear tank, then that is not what I understood before. And that suggests to me that you have a blown power valve or accelerator pump. If either of those things are bad you'll dump fuel right into the intake, and the higher the fuel level the more fuel since there is more gravitational pressure. Not "fuel pressure" as in pressure from the pump, but gravitational pressure caused by the weight of the ever-higher fuel. What I mean by it doing the same thing on the front tank is that if I let it sit for a few days and then start it, it starts with a normal idle and then after a few seconds kicks into the rough idle and stalls. It seems as though it runs fine until the fuel bowl fills up, which would make sense that it would run fine when I switch to the rear tank because it is probably just running on the fuel that was in the bowl. Just thinking through it logically, what you're saying about the pressure makes sense though. Link to comment Share on other sites More sharing options...
Bullnose Gator Posted December 13, 2021 Author Share Posted December 13, 2021 im assuming that this is a Holley carb based on the front fuel bowl reference. is it a replacement or a factory? more just for specific understanding really. mostly this sounds to me to be that the carb should be rebuilt thoroughly. first thought is that the needle cannot seal off the incoming fuel. if the carb has had the privilege of sitting for any length of time and ever had the chance to dry out then all rubber items are potentially dry rotted from the ethanol evaporation. It's a motorcraft, made by holley. I believe it is original, except for the front fuel bowl, which I replaced several months ago after I accidentally stripped the fuel filter intake threads. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 13, 2021 Share Posted December 13, 2021 What I mean by it doing the same thing on the front tank is that if I let it sit for a few days and then start it, it starts with a normal idle and then after a few seconds kicks into the rough idle and stalls. It seems as though it runs fine until the fuel bowl fills up, which would make sense that it would run fine when I switch to the rear tank because it is probably just running on the fuel that was in the bowl. Just thinking through it logically, what you're saying about the pressure makes sense though. Your latest description brought something else to mind - the choke. If the choke is set too rich the engine will start running rough and potentially die. What I'd do is start the engine, cold, with the air cleaner off and watch the choke. If it is still on a bunch when the engine starts running rough I'd manually open the choke a bit to see if that helps. If so, we are onto something. Link to comment Share on other sites More sharing options...
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