Since I'm on a role and haven't posted in many years, here's another dilemma that doesn't seem to really be a dilemma at all, just a quirk. And wondering if it was a normal circumstance? The same 71 Ford Maverick Grabber with 250 ci and what my search identifies as a carter 6163s carb with the large bowl on the front. When I test drove it, the seller had installed a choke and told me it had to be choked to run. I figured it had an air leak somewhere? And since it ran very well, I bought it. Well I get it home and I've tinkered like a mad scientist on this thing and came to the conclusion that it is indeed all original and only 74k miles. But I have replaced all the vac hoses with new ones and have drowned the motor in starter fluid with it running and can't for the life of me figure out where (or if) it is leaking air requiring the choke to be engaged to run. I've squirted every where I can without taking the motor out and running it on a stand so to speak. I have confirmed that the choke is indeed pulled. And what I did was taped the choke handle heavily with gorilla tape. It starts right up almost before the starter touches the flywheel. I can tap it and it will start. And it goes down the road like no other. I've driven it for 3 weeks now 56 miles round trip to work. Travelling anywhere from 5 minute idles at bleeding red lights to 80 mph down the interstate. And she runs like a dream.... As long as I can keep all the hands off the taped choke handle with this "what's this for's"... Is this normal? I rarely ask questions for something that works absolutely fine no matter the instance, but this one really bunfuzzles me. I'm not able to squirt starter fluid near the air horn so you think the carb itself is leaking air somewhere? Does this happen to anyone else? Should I just "rock it" and not ask questions with my taped choke? BTW, without the choke taped, it tries to suck open and looses it's power. Thanks ever again! Jeremy
You have a internal carb issue. If it has to be choked to idle, the basic idle circuit in carb is probably plugged up... Bogging under acceleration is usually float level or power valve related... All these conditions can be improved by partially closing choke... BTW later carbs that had the heated air intake often have the bogg issue without the heat, especially in colder weather...
weird, theres def a fuel issue there, id break out the carb cleaner. if you really get in a pinch I have a stock 250 carb thats clean I will let go relatively cheap. (converted mine to 2bbl). pm if interested, i'll try to dig it up.
The choke having to be partially engaged during idle indicates a lean fuel situation. I didn't read anywhere in your post about making an adjustment to your carburetor's idle mixture or curb idle? Have you performed either of those two procedures?
I did. But funny, I don't recall what the outcome even was at the time? LOL It's probably hard for anybody but me to figure that someone "doesn't recall" but since my collection (hobby) is 30+ and growing... I will go back and do it again this weekend. I would imagine it would not have made much impact on this carb since it seems to have internal air issues as mentioned? Most times when I rig something and it works I run with it... But since you ask, it won't hurt to ask if you think I did it right? I was taught by a professor at a tech school many MANY years ago (25-27 years to be more exact) so I'd say chances of improved technique is very possible since then. The way I learned was to idle it up a tad and screw the mixture screws in all the way and then out 2 complete turns. Then start the vehicle and screw the idle mixture screws in VERY SLOWLY until it starts to bog. And do both screws (if equipped) at the exact same distance. Usually 1/8 of a turn taking note of the flat head location. Then screw back out a quarter turn and roll. And take note how far in you gotta go before this happens. I was told that the further you have to screw it in from 2 turns, the more chances your carb needs attention. And if you go all the way in with no or little effect, you definitely have issues. But on other hand, the more you're able to screw it in to find the bog point, the better fuel economy you will get if you find that point before it goes all the way in. And then after all said and done, if Automatic, engage emergency brake, put in drive, turn on headlights and set curb idle. If manual, just set curb idle. Would this be how you would do it? And would any of this be your thoughts? Everything I learned on carbs was so long ago that it's never really dawned on me that technology might have caught up with me on that category. Any help (tips) would be appreciated!
Easy way is adj mixture screws for max vacuum, then reduce idle and re-adj if necessary... No 1/8 turn at time necessary... Using vac gauge will also tell you if there is a vac leak, late timing, valve sealing issue etc...
... presume the 250's carb is the "RBS" with low fuel bowl. Used to fit the taller decked (stroked 200) 250 small block six under the Maverick hood. If you really have that huge a vacuum leak to be compensated, look under the carb at the EGR return in the intake-to-manifold adapter the carb bolts to. If EGR tube or hose is broken it can result in vacuum problems... haev fun
Never used a vac gauge before. But I will be getting one soon! My old house had some unexpected things to pop up this past week to put a damper in my play time. Plus the holidays and a wife and family. Yes, that's the carb right there! Except it was either converted to or came with a manual choke. Too bad the bowl on these isn't an easy drop like a lawn mower or something. Sure would make it simple to clean it out knowing my gas tank isn't the best of shape. I added a see-thru fuel filter but have no idea how long it ran without a filter from previous owner. I did replace that hose. Along with everything rubber for it appeared everything was original. Didn't look very trusting for a 26 mile one way commute. But on good note, I'm still driving the car like it is. I notice a stumble on high end but figured that had something to do with the carb or the log manifold. I've got a carb rebuild kit on the way but have no idea when I will find time to get around to pulling the carb. Especially since it's still drivable. Thanks again! Ya'll have been a huge help as always!
