I'm not a big carb guy. I just put a new wiring harness in and got finished. Now that I can start my wife's scout again, the exhaust smells strongly of fuel and dies when I put it in gear unless I double foot it. Oh, we also did I rebuild kit on the scout just prior to the wiring harness. Can anyone give me pointers that I might be able to understand? From what I can see I have 2 air adjustment screws on the lower part of the carb that face forward. And 1 screw on the throttle assembly that will increase the throttle. Please help.
2bbl 2977 problems
- Thread starter timmy
- Start date
Scoutboy74
Moderator
You did a rebuild kit on what? The carb? How was it running and driving prior to the work performed? The idle/air mix screws at the rear of the throttle body should be turned out an equal 1.5 turns from gentle seating. That's a starting point. What type of choke does the carb have and is it adjusted and functioning properly? More to the point, can you open the choke plate fully once the engine is warm enough to run without choke assist? If you were to position yourself so you could look down into the carb with eye protection and a good light, would you see any liquid fuel drooling while the engine is idling? You don't want that.
Did a rebuilt kit on the carb, we had just gotten the motor to run. Did the rebuild kit and got it to start and run but did not drive it. Then I started the rewire process of a whole wiring harness replacement. When that was done I tried to test drive it. I found some stuff that needs more attention along with the stalling. I have done the 1½ turn from seated and have done half and quarter turns from there. And also increased the fuel screw, and adjusted the distributor so it sounds like it's running better. It will stay running if I double foot it. The choke is the original that is mounted on the intake and has a linkage that goes straight up to the carb. It will run fine at high idle and ok at low idle, it's only when you pit it gear that it dies, once you get it going it's ok.
Scoutboy74
Moderator
But you have no idea if the choke is actually working right. On your cold start the plate should be closed with a fast idle. As the engine warms, the plate needs to gradually open, either manually by pull cable or automatically either by hot air or battery voltage. It sounds like what you're describing might be a hot air auto choke setup. Whatever it is, it needs to work right. Pictures would be helpful. What year Scout is this? It also sounds like you're kind of guessing at where the base timing is set. Do you have a timing light? How about a vacuum gauge?
Erik VanRenselaar
Member
I guess timmy figured out the carburetor issue...
yearntolearn
Member
Unfortunately I haven’t figured mine out on my 800a if yall don’t mind me picking this one back up. It’s a 304 with the hot air choke. Not exactly sure this thing is working correctly or at all. I understand the metal windings that make it operate but I don’t see the way it links to the choke plate. I have uninstalled the idle mixture screws that came with the rebuild kit and installed the originals (the new ones are 1/4” longer?) I did this to try and figure out why it’s smoking so bad. Here’s a quick story.
Rebuilt carb
New fuel lines
Rebuilt fuel pump
New valve cover gaskets
New water pump
Rebuilt radiator
Start runs and sounds decent
Exhaust smoke seeming lightish - white that burns the eyes
Plugs are black as night
Thought carb adjustment so started playing with it and ultimately took the mixture screws that came with the kit out and reinstalled the original ones.
Vacuum gauge connected to a Tee intersecting the fuel pump vac line into the top of the block. 1/4 - full turns lean (from 2 turns out for a 2300 Holley) in small increments don’t seem to change much on the gauge. I’ll post pics after work. Thanks for any advice!
Rebuilt carb
New fuel lines
Rebuilt fuel pump
New valve cover gaskets
New water pump
Rebuilt radiator
Start runs and sounds decent
Exhaust smoke seeming lightish - white that burns the eyes
Plugs are black as night
Thought carb adjustment so started playing with it and ultimately took the mixture screws that came with the kit out and reinstalled the original ones.
Vacuum gauge connected to a Tee intersecting the fuel pump vac line into the top of the block. 1/4 - full turns lean (from 2 turns out for a 2300 Holley) in small increments don’t seem to change much on the gauge. I’ll post pics after work. Thanks for any advice!
Attachments
yearntolearn
Member
Only when I was in the carb. I did not do an adjustment through the site glass after install…
yearntolearn
Member
Scoutboy74
Moderator
Regardless of which choke design a given carb has, there are a few basic things most all will have in common. First, when the choke is applied with a cold engine prior to a cold start attempt, the plate should be fully closed. With a cable actuated manual choke, this is accomplished by pulling the dash knob out, with the results being easily verified without the air filter canister in the way. With most auto chokes, the way to actuate them before a cold start is to fully depress the gas pedal. Naturally, there is a fair amount of adjustment that comes into play in properly dialing an auto choke. Once done, the results should display in the plate being fully closed with a throttle pedal stab. You can and should verify what your choke plate looks like prior to a cold start. The next common choke characteristic is they need to open or come off as the running engine builds heat. With a manual choke, this is done by pushing in on the dash knob, partially at first and then eventually all the way so that the plate is fully open. With an auto choke, the opening or pulling off of the choke happens in a slow, gradual motion until a fully open plate is reached. This process will take 5 or more minutes to go from fully closed to fully open, unless the operator decides the engine has warmed enough to stay running at curb idle with no choke applied and chooses to interrupt the gradual pull off by stabbing the throttle to override normal choke function. Once again, this gradual choke pull off from fully closed is something you can verify with the filter canister removed. Just watch it as the engine warms up and see what happens. The other common feature of a choke regardless of design is the incorporation of increased idle speed while the choke is applied. Once again, some adjustment is required to set this up properly, but a high idle speed is very beneficial when attempting to keep a frigid engine running once started. In the case of a manual choke, there is essentially a cam lobe in the choke mechanism that will force the throttle linkage partially open when the dash knob is pulled and the plate is closed. As the knob gets pushed in, the plate will open and the engine speed will also decrease in kind. This continues until the knob has been pushed all the way back in. With an auto choke, there is a different kind of a cam as part of the choke mechanism that has a couple serrated "steps" molded into it. At full application, the engine will be running at a fast idle speed of about 1600 rip-ems and should then auto-magically step down in roughly 200 rpm increments from there several times until the choke has come fully off and normal curb idle is achieved.
IMHO, auto chokes tend to be fussy and finicky and require periodic adjustment to maintain optimum performance as the seasons change. They're also prone to sticking and stubbornly refusing to do the incremental rip-em step down process, which results in the maximum fast idle remaining engaged even as the choke plate has fully opened. The hot air auto choke deign you have is a very primitive and cumbersome setup that is likely to be more trouble than it will be worth to make work properly. It's basically not so hot garbage. That leaves you with two options. Convert to a 12 volt electric auto choke or convert to a manual choke. Holley offers after market conversion kits to modify your carb either way. Electric auto chokes can be nice when they're setup properly, but again this can prove to be a tedious process with much trial and error often required. A manual choke, while certainly not nearly as sexy, is about as simple and basic and reliable as it gets. It does require some attention and input from the driver as the engine warms. Definitely not a set it and forget it option, but let's face it. You're not as much of a multi-tasker in the morning while you're warming up the Scout as you think you might be. It's a good opportunity to sit there and sip on that cup of morning mud as you attend to your low tech, but ultra-simple and reliable manual choke.
IMHO, auto chokes tend to be fussy and finicky and require periodic adjustment to maintain optimum performance as the seasons change. They're also prone to sticking and stubbornly refusing to do the incremental rip-em step down process, which results in the maximum fast idle remaining engaged even as the choke plate has fully opened. The hot air auto choke deign you have is a very primitive and cumbersome setup that is likely to be more trouble than it will be worth to make work properly. It's basically not so hot garbage. That leaves you with two options. Convert to a 12 volt electric auto choke or convert to a manual choke. Holley offers after market conversion kits to modify your carb either way. Electric auto chokes can be nice when they're setup properly, but again this can prove to be a tedious process with much trial and error often required. A manual choke, while certainly not nearly as sexy, is about as simple and basic and reliable as it gets. It does require some attention and input from the driver as the engine warms. Definitely not a set it and forget it option, but let's face it. You're not as much of a multi-tasker in the morning while you're warming up the Scout as you think you might be. It's a good opportunity to sit there and sip on that cup of morning mud as you attend to your low tech, but ultra-simple and reliable manual choke.
yearntolearn
Member
I appreciate the responses - So, I opened the fuel bowl site screw and it’s not as if fuel was pouring out, which is how I imagined a high fuel level. I do notice minimal wetness around the curb tho so I guess I need to check torque on those bolts. For the choke plate, what I mean is I’m not confident in the auto choke windings capability of engaging the plate to close. As if I missed a step when reinstalling the choke. The choke plate is always opened - regardless of temps. Which in Maryland I guess could be possible for another couple weeks…I’ll take a video of the choke plate linkage when I get home if that helps.
yearntolearn
Member
Ok - choke spring was not seated properly - so that’s fixed and now choke plate functions and choke opened choke plate upon warming! Nice!
So I bled the fuel bowl per book and started up - the level was just at the bottom of the screw hole but some did trickle out so I lowered a touch. Question - the 2300c fuel bowl spec says 3/8” at 5.5psi. Which I guess I need to measure that as well?
I reset the needles 3 turns off seat per book as well. Not much of a difference on the vacuum gauge when trying to lean out. Thinking my gauge is bogus. Burning eye smoke still present although before I started to attempt to lean best idle I thought it was nice and steady.
So I bled the fuel bowl per book and started up - the level was just at the bottom of the screw hole but some did trickle out so I lowered a touch. Question - the 2300c fuel bowl spec says 3/8” at 5.5psi. Which I guess I need to measure that as well?
I reset the needles 3 turns off seat per book as well. Not much of a difference on the vacuum gauge when trying to lean out. Thinking my gauge is bogus. Burning eye smoke still present although before I started to attempt to lean best idle I thought it was nice and steady.
yearntolearn
Member
I’m waiting on a timing light and new vac gauge for that.Was mostly going by sound until I couldn't get rid of the issue. Hoping I have it by Monday.
yearntolearn
Member
Welp - Timing light worked for a second and then both the light and the tach stopped working. Deeming the tool useless. It wasn’t exactly cheap but I figured I’d ask if there’s a brand you guys use? I tried the innova 5568 and will be returning.
Scoutboy74
Moderator
How do you have it hooked up? Tachometer receives input from coil negative post, so if something is wrong with that connection that could foul it up. Most timing lights are pretty basic as far as connections. Good contact with battery posts and inductive clamp on #8 plug wire for International V8 engines. Most other makes time off #1 wire.