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Carb issues any suggestions?


phillobbezoo

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So on my 2012 I just picked up I ordered a rebuild kit for the carb, put it all together and it runs like a top after a few adjustments. I walked away to put away the tools came back 10 mins later and gas was leaking from the bowl gasket, checked the screws and they are tight and yes I made sure the old gasket was scraped off and clean before I put it all back together any thoughts?

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Hmmm...From the bowl gasket? Sounds like the needle isn't seating. Do you have the metal tip needle with n o-ring seal seat or the viton tipped needle with a brass seat. You can use a q-tip with some black rouge to polish the brass seats. Chuck the q-tip in a hand drill. The paper stem doesn't hold up to too much pressure...it actually works pretty good.

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Phil, 620 was leaking from what I thought was fuel bowl gasket, turned out to be holes in the fuel bowl after cleaning. I bought new gasket and the like but ended up epoxing the bowl stopped leak. Just my $.02

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Okay so I pulled the carb back off adjust the seat check it before I put it all back together to make sure it was closing and it was put it back together started up walked away came back and it's still leaking around bowl gasket so I dunno

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When you had it apart, did you shake the float to see if it had fuel in it? (Meaning a pinhole somewhere in the float) or if its a plastic float than like bob said could be dissolved by the fuel.

How did it look? Any rust/ off colored spots?

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Didn't shake it around really, didn't notice any rust but there was a few off colored spots I guess but I dunno, I guess I'll have to take it back apart and pay a little closer attention to the float I guess, maybe I'll just order a new one. Does any one kno if this is the right part number for the float 299707? Thanks for your help I appreciate it

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Yep, take it out and shake the float. Amazing what a little water in the bowl will do to the float when it freezes. I successfully soldered a tiny crack on my Lincoln Welder Briggs twin because I didn't want to wait for a new one. Found a great tutorial on one of the hot rod sites for soldering floats.... was easy.

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You may want to check the carb flange surfaces for warpage with a straight edge as these pot metal carbs are prone to that due to over tightening the 4 screws. As I recall, the top body of the carb is more prone to this kind of damage. A replacement top body "was" pretty reasonable from Briggs, like in the $30 range, but like everything else it's probably more now.

Tom (PK)

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Yeah I found a whole new carb for like $50 on eBay it's suppose to be the replacement carb for these engines thinking of just buying a new one and being done with it

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IDK if i would buy a brand new carb, call me a pessimist but i bet if you buy a new carb it will be a knockoff of somewhere, and not last you nearly as long as the one you have. If i were to look for another carb, i would look for a used or rebuilt carb of the same era. But that's just me you do what you feel comfortable with. Also, if this is a brass float, than the little tab that the needle valve sits on could just be bent. And that is a very easy adjustment to make. The part number i came up with for a float is 692265 but i almost guarantee that is plastic. Also, your part number 299707 comes up with a brass or plastic float they both use the same part number now. As much as i hate plastic floats, i will admit i haven't had one issue with mine for almost 3 years now.

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It is a brass float I did adjust the tab on it, I'm wondering the old gasket I took off/wrecked when I took it apart was thicker then the new one and it was almost like rubber it was different then the new paper gasket i got with the rebuilt kit, I starting to wonder if one of the halfs is tweaked just a little, I know the top half of the carb is still like 45$ bucks or something like that, I'm out at the lake I guess I'll have to check it out next week

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You could try using two gaskets. If your top half is warped, I have a procedure for fixing that. Contact me off list so I can send pictures. edstoller at earthlink dot net

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Has anyone used these after market carbs good or bad??? I know when I use to race atv's everything aftermarket was better then stock but that's a very different world, any thoughts ???

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Okay so I got home from the lake went out to the barn and pulled carb back apart, checked the float and is fine. Got a torpedo level out and the top half of the carb is warped set the halfs together with out the gasket in and you can see light inbetween the screw flanges so should I buy a new top half or a whole new aftermarket carb price difference is about $13 between the 2 thanks

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Phil,

If it were me, I'd opt to buy the B&S top half of the carb (now ~~$34 from Jacks). When you buy a complete knock-off China eBay carb, you really don't know what kind of quality you're getting. The B&S PN 299687 top half includes all the known wear items; throttle shaft, butterfly, idle stop lever w/roll pin, etc. If the lower body gasket surface is true/not warped, then you'd essentially have a brand new carb since you already have the rebuild kit parts.

Tom (PK)

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I just went through the same thing on a 101. There are variations in the carb over the years. My kit came with two needles. One was packaged with a new seat and one was in with the rest of the parts.

Since my carb does not use a threaded in seat I used the float needle that was in with the rest of the parts and it turned out to be too short. The tractor would start, the bowl would fill with gas but the needle would not close off the flow cause it was not long enough and the fuel would just keep pouring in and overflow out the bottom of the carb.

I opened the package with the needle and seat and found the needle in there was slightly longer. I swapped them out and after I got the float level set the problem went away.

Compare your old needle with the new one for length and see if your kit came with more than one needle.

The generic kits often come with the extra parts that account for the minor variations in the carb design over the years, you just have to figure out which parts are correct for your application.

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I'm wondering if that might be part of the problem, I got the top half of the carb today put it all together tonight, and it's not leaking around the gasket anymore, but I still noticed a small trickel of gas going down the air intake tube not bad and it only does it when it's not running so I'm going to pull it back apart tomorrow night maybe and play with the needle some more I guess starting to get frustrated

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If it runs but leaks gas, an inline fuel shut off solves the problem nicely. I put them on all gravity systems. Saves the needles, too

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I imagine he is using a manual shut off I put one on my big ten even tho I got the carb to stop leaking but readjust the float several times before I got it right

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Thanks Phil. I have a 3112V with the exact same problem. I am going to try the things mentioned above, but I can say PO did some "work" and there is now an aluminum seat (kind that doesnt screw out, but will come out with finesse). I got a couple of carb kits, some with viton tips, some with aluminum and a viton ring. Same result with all of them. My question is, with the aluminum seat, should it be flush with the upper body surface, protrude at all? If I use the alum needle (or does it matter?), should the viton ring stay in the seat (mine falls out).

Thanks guys!!! Many Many Many hours being frustrated with pools of gas on the garage floor. Im with ya Phil!

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Manual, in-line. Most engines with a gravity feed have a shut off on the bottom of the tank. I open it fully or remove it, and install an in-line valve. Auto causes problems, manual rarely has a problem

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Thanks MrSteele, I have heard about auto shut offs on motorcycles and seems like were mentioned in a tractor site and was interested in hearing anyones experience. I don't always remember to turn off the manual valve

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