Hello from the Netherlands, my car is difficult to start afther a few days. So I find out that my float chamber is empty. The gasoline leaks out. NOT at the outsde of the carburetor Now I saw on Quadrajetparts.com that the secondary well plugs can leak. And they had a solution for that. O- ringed plugs. But they are out of business. So any other solutions or ideas? Its a Quadrajet: 17057142
Most of the time it is just the gasoline drying out. The bowl is open to the atmosphere via the vent and gasoline will evaporate. If it truly is the well plugs, you can the carb off and epoxy them over.
Modern gasoline is engineered for a closed fuel system that is not open to the atmosphere; the exact opposite of an engine with a carburetor. Nine out of ten times your problem is caused by fuel evaporation from an open-to-the-atmosphere carbureted fuel system.
So everybody has the same problem with a carburetor? Is Quadrajetparts.com realy out of business. Or is it just temporary.
Yes everyone has the same problem. quadrajet parts .com is permanently closed. The owner passed away recently.
17057142 is a 1977 m4m carburetor Very unlikely to leak at the well plugs. Evaporation and drain back thru the needle and seat are much more common causes of your issue.
Remove the little wire needle hanger. When the bowl level starts to drop due to evaporation, the float won’t pull the needle out of the seat, eliminating drainback.
When you leave the little wire needle hanger, is there is not a good chance that the float needle will stick? I put the epoxy on the well plugs anyway. Better safe than sorry. Any other ideas are very welcome.
If my car will not be started for more than 2-3 days, I use a bottle like this, https://www.amazon.com/gp/product/B005Z4RGQW/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&th=1 to fill the fuel bowl with gasoline.
That’s a good idea Larry. I’m lazier than that though. I just go to Dollar General, or any pharmacy, and buy a baby snot sucker. You know, the little rubber thing you stick up their nose and suck the snot out. It works great.
Yes, I have had two customers send me freshly built carbs, from the same builder who insists on not installing the needle pull wire. The first one was a bit of a head scratcher, it happened on the dyno, and it took a bit (at $100+/hr) to locate the issue.. silly me, I assume that a professional would put all the parts back in... the second one was much quicker, just a shot of air in the fuel inlet and "Pop" it came free. So unless your smarter than the engineer that designed the carb, put all the parts back in folks.. JW
I have one of Ken's electric choke conversions. What I do is open the throttle to set the choke blade. Then fill the bowl through the vent up to a day before I know I will use the car. There is enough evaporation from the bowl that all I have to do is twist the key, and the engine starts instantly, fast idles, and I can drive away even in cold weather without two footing it.
I asked the same question awhile ago... I just run the starter for 1 Mississippi 2 Mississippi 3 Mississippi. That lets the pump fill the card with enough fuel... Then I pump the throttle once or twice hit the stater .. fires right up..... Yes I do have Ken's electric choke also....
Interesting, since I never thought of removing the little clip but read that Cliff does it, or maybe used to. Maybe he will weigh in. I had one that someone drilled out the primary jets to at least .080” that was causing the engine to foul most of the plugs at slow speeds. Burns-your-eyes rich, sucking fuel worse than a Holley. Probably worked great on the dyno, but people don’t drive dynos. And this was fresh off the dyno, with supposedly great A/F numbers. Caused me all sorts of fits at $100/hr. Cliff found that when that carb was sent to him, and he pin-checked them. I would have never thought to do that, because who drills jets to get more fuel on a 450HP build? Silly me, live and learn..
I've seen carb kits come with a different type of needle/seat combo that doesn't use the hanger. That might be the "correct" way to make that modification. I've never put one in myself. I never trusted it.
One of the tid bits that I read from Cliff not long ago was the fact that the needle clip is a tuned part. Set up so that with very little movement of float the needle starts to lift. Never thought about such a little seemingly insignificant part being tunable and important.
Couple of things. The bottom plug leaking thing is mostly a myth. ALL q-jets leaked from 1965-68, the ones that used the thin brass cups in the rear and little lead tapped in plugs in the front. By 1969 Rochester realized their mistake and made the castings thicker and started pressing in solid aluminum rear plugs and sealing them (basically running a high speed swaging apparatus over them). Leaks in and after 1969 are rare, but in in and all cases leak test your casting BEFORE making any repairs to is. If you find a leak at the large rear plugs 99 times out of 100 a few gently taps with a small machinist hammer will stop them. I'll add here that pulling out solid aluminum plugs and installing those POS "O" ring plugs is going BACKWARDS as every single carb I've ever worked on that had them leaked right thru that junk like Niagra Falls! Front plugs eventually got the same treatment as the rear ones, swaged in aluminum plugs so leaks there were eliminated by the early 1970's although I've seen a few later Carter units still used soft leak plugs in the front. IF you find a front plug leaking it MUST be removed and the casting tapped for screw in plugs coated with Marine Tex or fuel grade epoxy. JB Weld is USELESS for that issue BTW, and 100 percent of the carbs I've had in here repaired with JB Weld that were leaking leaked right thru it and 95 times out of 100 the glue was soft and either fell off or I could peal it right off with a pocket knife. I'll also add here that smearing "monkey chit" over rear plugs is STOOPID right to start with as it can and will hold the main casting away from the baseplate and cause an internal vacuum leak when the gasket fails to seal and binding of the secondary throttle shaft. I'm probably helping out some "builders" with that statement but I'm not doing carbs these days unless I need to re-stock the Bourbon bar so it may help folks with those issues that can't figure out why their engine idles too fast or refuses to return to idle after a full throttle blast. Let's move on. My rebuild kits come with a solid fuel inlet seat, the "windowed" variety are outdated and obsolete as there is ZERO improvement in fuel flow vs the solid one. The solid fuel inlet seats were in place by the mid-1970's to keep the carb from draining back and they also started using those restrictive spring loaded check valves in the fuel filters (not recommended) to help prevent that issue. I do NOT advocate leaving the clip off the needle even though with a full fledge race car and electric pump you might get away with it. The clip isn't your enemy anyhow and it's ONLY purpose is to raise the needle when the carb dries up to keep it from getting "glued" in requiring beating on the casting, blowing high pressure air into the inlet, or removing the top to free it up. While were are on that subject you MUST custom fit and "adjust" the clip or it's not doing anything and can and will get cocked sideways and cause a flooding issue. Plus it gets installed open end facing the front (that's the fuel filter housing end) of the carb, NEVER hook it in either one of the holes in the float arm as it can get bound up and cause a flooding issue. One more important tid-bit. On every single Forum, Blog or Website you visit and the empty Q-jet bowl topic comes up there will ALWAYS be a host of gurus, resident experts and folks who needed to keep their day jobs chiming in saying that "your bottom plugs are leaking" causing difficult or no-starts after a day or two of sitting. In reality in almost all cases it is either a choke issue, or the accl pump seal has failed or you have a fuel delivery issue not returning fuel to the bowl. I see THOUSANDS of "blue" accl pump seals causing this issue as they swell up in this new fuel and stick tight in the bore not allowing fuel past them on the upstroke of the pump. So you crank and crank can pump and pump and crank and crank and pump and pump and eventually the engine will fire up or you just get all pissed off and dump a little fuel in it to get things going, sound familiar? In closing I'll add that my rebuild kits come with a USA made lifetime warranty seal on them AND the N/S assembly has no windows and the real .135" high flow variety.....hope this helps some.... https://cliffshighperformance.com/product-category/quadrajet-rebuild-kits PS: pic below of three seals, all spent a couple of hours in 93 octane with 10 percent ethanol. The left seal is from a NAPA kit for early carbs, the middle seal a Walker kit, and my USA made seal. Which one do you want in your carb?...
