Carburator for dummies

katsi · Post by **katsi** » Thu Jan 12, 2012 10:51 am

Anyone know how to dial in a carb? Mine is definatly off but I have absolutly no clue as how to adjust it. I get A LOT of backfires when I take my foot off the gas. It floods when I try to start it when it's warm but idols fine once I get it started (got to do the peddle to the floor start). I get a very strong fuel smell when I turn it off and I can't find any leaks.

Anyway, this is pretty new territory for me so does anyone know of something I can read to get me up to speed on the subject? I can, however, fix the carb on my lawn mower.

vandor · Post by **vandor** » Thu Jan 12, 2012 11:15 am

If it floods then likely that is not an adjustment issue! I suppose the float level could be off, but it's not something that changes by itself.
Sounds like the carb needs a rebuild.

124JOE · Post by **124JOE** » Thu Jan 12, 2012 12:24 pm

how is your choke?
is is moving to closed?it my be too warm outside
you can leave the car off and check your setings

katsi · Post by **katsi** » Thu Jan 12, 2012 5:16 pm

124JOE wrote:how is your choke?
is is moving to closed?it my be too warm outside
you can leave the car off and check your setings

Will check this eveing.

vandor wrote:If it floods then likely that is not an adjustment issue! I suppose the float level could be off, but it's not something that changes by itself.
Sounds like the carb needs a rebuild.

Yeah, I was just hopeing to fix it before I purchased a rebuild kit from you. Because after I rebuild it, I will then have to take it to a mechanic for the second, correct rebuild.

aj81spider · Post by **aj81spider** » Thu Jan 12, 2012 6:17 pm

Because after I rebuild it, I will then have to take it to a mechanic for the second, correct rebuild.

Hey! That's my plan too!

dmwhiteoak · Post by **dmwhiteoak** » Thu Jan 12, 2012 9:30 pm

There is really not that much too overhauling one of these webers. Just remember where everything goes and take a few pictures before you tear it down. Where is Katy anyway, is that just north of Houston?

blurple124 · Post by **blurple124** » Fri Jan 13, 2012 1:25 am

An easy place to start would be to check all of your engine hoses. It sounds like you have more of an issue than just that, but I had backfiring when I bought mine because the PO hadn't changed the hoses since original (or so it appeared). Lots of air was getting into the engine causing the issue. I changed the hoses, and no issues since!

Like I said, this would be a cheap and easy place to begin.

katsi · Post by **katsi** » Fri Jan 13, 2012 9:57 am

blurple124 wrote:An easy place to start would be to check all of your engine hoses.

I did replace all the fuel hoses and it did improve the carb performance a lot.

dmwhiteoak wrote:Where is Katy anyway, is that just north of Houston?

Just west of Houston.

jsab · Post by **jsab** » Fri Jan 13, 2012 10:41 am

You need to check the vacuum hoses and system also, holes in these will also cause backfiring on deceleration.

katsi · Post by **katsi** » Fri Jan 13, 2012 12:16 pm

jsab wrote:You need to check the vacuum hoses and system also, holes in these will also cause backfiring on deceleration

What vaccume hoses are you referring to?

I changed everything to a very simple webber carb. Most of my vaccuum lines on the intake have been capped off. I have a single plane intake form a 74 (I think) on my 79.

majicwrench · Post by **majicwrench** » Fri Jan 13, 2012 12:23 pm

Backfiring on decell is not really a big issue, and may, or may not be carb related. Holding your foot down and cranking an cranking a flooded engine, that is a carb issue and needs to be adressed.

I cringe every time someone comes into my shop and says "I rebuilt my carb last weekend, and now all it needs is some adjustment...". If you do it yourself get a good manual and a clean work bench, take some pics. The float, needle and seat, and idle circuit are important.
Keith

katsi · Post by **katsi** » Fri Jan 13, 2012 5:41 pm

124JOE wrote:how is your choke?

Perminently open. Will not close. It's a water choke so I bet it's rusted.

I purchased the carb on ebay for the high bid of $24.00. I bolted it on and she fired right up. I did some monor adjustments to the idle screw and it was fine.

After sitting in the garage for over a year, I got the gumption to put in a new suspension (was almost undriveable). Now I'm ready to drive again and she has developed this problem.

Oh yeah, I went to adjust the mixture screw last night and it would not turn either right or left. I gave it a little bit more force, nothing big, and it broke off compleetly. So, I guess the mixture screw adjustment is no longer an option.

majicwrench wrote:Backfiring on decell is not really a big issue, and may, or may not be carb related.

Yeah, only on decelleration. I adjusted the idle screw (the one on the carb throttle) and that didn't help anything. The mixture screw - read above

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