73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: txchainsawgogi on February 07, 2011, 06:36:29 pm
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ok, so im replacing the carb as soon as i can but i still need to get to work (and my motorcycle has a flat rear tire) so any suggestions would be nice.
the carb was leaking pretty bad and it was causing it to run terribly. i replaced the main gasket between the intake and the carb, then it ran really well twice... and now today its leaking again.
its coming from the sides near the vacuum break assembly and at the top right hand side from (what looks like) out of the pump assembly rod.
are all my o rings just shot to heck from old age?
ill try to get these pics to work...
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You could do a quick rebuild in a few hours. It looks like your accelerator pump is leaking, but I'm not sure where the fuel is coming from on the other side of the carb. If its all running out of the accelerator pump and running down the other side you can take the air horn off and replace it without even taking the carb. off the truck--far less than an hour's work.
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I am with jaredts, it is not hard to rebuild your carb., it looks like your floats might be sticking also flooding your carb and running out where ever it can. I would say buy a kit, take it off and rebuild, then your o-rings, gaskets, floats and needle and seat would all be new. I didn't look too close if it was a q-jet, but if it was make sure to get new throttle bushings also.
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I'm a little scared to do a rebuild on it, I don't want to waste the time and money and have it still be messed up.
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I'd do a quick rebuild, it's prolly fairly clean in there. I wouldn't worry about the throttle bushings right now. That can wait until you get time to refurbish the carb right or if you prefer, to put an aftermarket carb on there. Just keep track of everything as you reseal the carb.
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No need to waste money on buying a aftermarket carb. If your going to go through the hassle (which isnt much) of rebuilding the carb (which wont take long-couple hours at most), DO the throttle bushings. Rebuild kits are cheap. Buy a book on how to rebuild and tune them properly as well. They have them in the book section at the auto parts stores.
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the thing about it is that i need it fixed soon. i cant get a good rebuild kit locally so i'd have to mail order it :(. i can get a rebuilt rochester locally though.
i'll see what kind of kits autozone/oreilly has... but last time i checked they only had brands that i saw had a negative rep on here.
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The oreillys here had a Walker brand rebuild kit for the stock rochester qjet for like 16 bucks. Maybe yours will have it to?
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I'd say, you're better off getting a new tire for the motorcycle and taking your time with the rebuild. But when I was in Austin last thursday, it was like 17 degrees in the morning. Brrrrrrr. I'd steer away from those parts store rebuilds.
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When you do order the kit, make sure it has the throttle bushings. Check with summit or jegs too. I think there is a online carb place that has them too, someone posted something about it on here. Try searching it.
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Search for cliff's high performance. Has a good book out too.
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I've never done throttle bushings. The reason is that it requires special tools. You can buy a kit that comes with a long reamer that guarantees the two bushing bores are parallel so the shaft can have a tight fit but not bind. This kit is a little on the expensive side for me (well over $100 iirc). You can do a cheap parts store rebuild for under $30, but if the bushings are necessary I personally wouldn't do it myself. Its not that I think its hard, its just that you're getting into enough money that its not worth it to me compared to buying a rebuilt carb. that already has bushings installed. Unless the shaft is really loose a rebuild will yield acceptable results. If rebuilding it yourself is not in the cards than shop around for a rebuilt one or get a brand new quadrajet from Edelbrock (I think they're still available) or dare I say it--an aftermarket carb.--blasphemy!
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I got the bushing kit from Cliff's and it was about $75 if I remember right. It came with the special bit and enough extra screws and bushings to do 2 carbs. I used it successfully on my own and on my neighbor's q-jet from an 80 K10. The most tedious part was bending the linkage arm so that the main throttle shaft will come unhooked and slide out without breaking the rod. It's really a pretty easy task but there is some risk of screwing it up big time.
To anyone that does this themselves:
DO NOT try to remove the little screws holding the throttle plates in the traditional manner.
DO twist the heads off by overtightening and then use a very sharp small vice grip to grab the other end and thread them the rest of the way out. They are peened on the end and do want want to be threaded back through the hole.
Only drill as deep as you have to, but make sure that the bushing doesn't extend past the outside edge of the plate or the end of the shaft won't stick out of the other end far enough to put everything back together.
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I'm gonna do the rebuild to fix the leak, but imholding off on the bushings myself.
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Before you rip anything apart you can diagnose whether the throttle shaft is leaking or not pretty easily. Grab the throttle on the driver's side of the carb where the cables hook up. Without turning it (to give it more gas) just pull the entire thing forward, and push it back towards the firewall a few times. If you can hear any whistling or it makes the idle surge you know that it's leaking. Also if it feels like there is excessive play it probably leaks when the throttle is opened up a bit, or it's going to be starting to leak very soon. If it's good and tight, don't worry about it, but if it's sloppy or it obviously leaks, don't waste your time and money on rebuilding the carb unless you put the bushings in too. It will never ever run right. The bushing install is nothing to be worried about. You can't really screw up drilling the holes because of the way the bit is designed. I've got a picture of it on here someplace in another thread. About the worst thing that can happen is you break the linkage rod or twist off one of the screws and can't get it out, but if you take your time you'd have no trouble at all. But definitely check it before you take the carb off.
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Ah dang I already bought the kit. I'll try this before I take the carb off though...
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Grim, I did what you said. No surging or whistling. The linkage actually felt really tight, not too tight...just normal.
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Glad to hear it. You should be good to go after the rebuild 8)
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I'm a little confused by the rods on the linkages... as in what order to remove them so I can seperate the carb body. Hope I can get it back together!
This rochester is way more complex than motorcycle carbs that I'm used to.
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Your leak on the bottom is most likely the plugs on the bottom of the carb. They are known to leak. the fix for it, and it will probly mention it in the rebuild instructions is to put two pools of epoxy over them.
(http://i1198.photobucket.com/albums/aa446/acefoxx/plugs.gif)
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great. everything was going fine until this little piece of plastic (that isnt even in either diagram i have) broke into 3 pieces. i'll try and post a photo of it, and where it goes...
what will happen if i put it back together without it? it seems like the metering rods wont be in the right place without it. its total bs because not only is it not in the rebuild kit, its not in any exploded view diagram AND it doesnt look like its serviceable.
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in the first picture, it goes right in the very middle... in between the butterflies.
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You need it, and Cliff has it for $8.
http://www.cliffshighperformance.com/parts.html#a
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godddd thats such bs. i really dont have time to order things online... which is the main reason i bothered rebuilding the carb. im sick of trying to get rides to work.
i dont even understand how im supposed to put a new one onto that shaft.
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order that there book on rochesters as well.......... i might. even though i dont use the gas carb all that much....
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In the time it took you to post that online, you could have ordered the part ;) Also order the book so when I take my q-jet off the shelf and rebuild it you can help me out ;D
Hang in there, you'll get it.
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You might have to hit a junkyard to see if there's one you can steal. Or a speedshop like Austin Performance and Specialty. I've never used them, just googled a little.
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Haha yeah I couldhave ordered it...but id still have to wait a week!
I THINK I fixed it using a washer and drimmel. But I still plan on getting the actual part. Also figured out how to get the butterfly rod thing out. Everything is back together but I'm a little worried about the linkage on the passenger side of the carb...guess ill see in the morning how it runs(or doesn't).
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be careful with that. A washer is the last thing you want bouncing around in the engine
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true, but its a little plastic one almost the exact same as the one that broke. looks like the same material as the one on the cliff's website.