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hatepotholez

Engine only runs with starter fluid

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On 3/14/2016 at 4:49 PM, siteunseen said:

Make sure he nozzles are moving freely. Choke cables could hinder that.

nozzles move pretty freely. Still not sure if I connected the choke cable correctly though. 

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You need to loosen the screws on the dome, get the damper moving freely then tighten them down.  That little rubber blob that supposedly lines them up isn't even on mine.  Loosen the screws a little.

The choke is on when the handle is pulled back towards the rear of the car.  When the choke is on the nozzles drop down about an inch.

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    Oh yeah, I've dropped them too.  Now I place a rag with a small hole on the cowl and set the piston on it with the needle protruding thru the rag and into one of the cowl slots. The piston sits securely on the rag and the needle is protected from my clumsiness.

  To be sure the needle isn't the problem, blacken the needle with a Sharpie pen and slide the piston up and down. If there is contact, the black ink will be scraped off revealing the brass contact point. This will also work for locating interference between the piston and chamber.

 The choke is activated when the handle is pulled into the up position. At the carbs., the choke cables pull the fuel nozzles down. This temporarily boosts the amount of fuel in the mixture. Virtually the same action as dropping the nozzles down with the adjustment screws.

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Ok, so handle up and nozzles down. This would let in more fuel. got it!

I loosened the pot and it still doesn't drop down and get's stuck. I also rotated the pot and at certain positions the damper will go up and down slightly. 

Great idea. I will use a sharpie and see where it's hitting and try hitting the emory cloth in that area. 

for the needle does it have to be perfectly at 90 degrees? My needle is bent a little to the side but drops down into the nozzle fine. I have replacement needles, but I prefer not to change out the ones I have just jet.

 

Thanks guys!

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It sounds like the shaft for the pot is bent a bit. Try swapping the pots between carbs. Maybe it will work better. At least if the problem moves with the pot or not you will know which component is actually at fault.

Have you inspected the bore the pot rides in? Perhaps there is a some debris in there or maybe it is not round or not straight. What type of measuring tools do you have to inspect such things?

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50 minutes ago, beermanpete said:

It sounds like the shaft for the pot is bent a bit. Try swapping the pots between carbs. Maybe it will work better. At least if the problem moves with the pot or not you will know which component is actually at fault.

Have you inspected the bore the pot rides in? Perhaps there is a some debris in there or maybe it is not round or not straight. What type of measuring tools do you have to inspect such things?

I believe we might have something at my job to measure the bore. Something is bent or there is a nick somewhere binding when the pot and damper are installed. 

I cleaned out the bore, I ran a papertowel soaked in carb cleaner through it and then cleaned it all off with carb cleaner. When its all installed this is when I have the sticking issue. It was bad and then got worse after it fell. 

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  Have you tried beermanpete's advice about swapping pots (and pistons) between carbs? You'll be able to tell which part is bent, Piston or pot. IMO I'd start looking for replacement part(s) ASAP. I doubt if it's worth the time and money to try to straighten it. Whatever "it" is.

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Are the carbs 4-screws ? The early carbs have a much different procedure for aligning the nozzles. I can't explain it because I have 3-screws with a fixed lateral location for the nozzles, so I never bothered to learn it. The ZTherapy video explains it in detail, though. Also, it should be in the '71 FSM.  

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I have a 3 pot, i'll go back to the Ztherapy DVD. Apparently I skipped through this part.

Mark, I have not and I might not since the rear carb is working beatifully lol.   

I'm trying to source parts as we speak.

 

 

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10 hours ago, siteunseen said:

Chuck the needle in a drill and slowly work it with emory cloth.

 Cliff,  I think a drill motor would be an excellent method to determine straightness of the needle but when finished with this sanding procedure aren't you left with one carb running richer than the other or are you compensating with the nozzle adjustment? It seems to me that new needles would be the better answer. 

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Be careful using abrasives to clean the needles. If any of the original material is removed it will affect the fuel/air mixture. If the needle is bent replace it. They are not hard to get.

The symptoms reported indicate a problem with the damper (pot) at the top of the carb, not the needle. Focus on one issue at a time and do what you can to isolate the various components in the system to determine which part is at fault. For example, remove the pots and see how the vacuum piston moves. If it move freely then the needle and nozzle are ok. Next, add the pot if the vacuum piston now sticks the problem is with the pot or the bore it rides in (in the vacuum piston). If there is still doubt about the culprit, remove the nozzle and/or the needle and check the piston operation again with only the pot. Divide and conquer.

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31 minutes ago, beermanpete said:

Be careful using abrasives to clean the needles. If any of the original material is removed it will affect the fuel/air mixture. If the needle is bent replace it. They are not hard to get.

The symptoms reported indicate a problem with the damper (pot) at the top of the carb, not the needle. Focus on one issue at a time and do what you can to isolate the various components in the system to determine which part is at fault. For example, remove the pots and see how the vacuum piston moves. If it move freely then the needle and nozzle are ok. Next, add the pot if the vacuum piston now sticks the problem is with the pot or the bore it rides in (in the vacuum piston). If there is still doubt about the culprit, remove the nozzle and/or the needle and check the piston operation again with only the pot. Divide and conquer.

I did exactly what you are describing. Everything is fine once the pot is screwed down then it starts sticking. I can't remember if I always had this problem with the front carb. 

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What about the hole in the top of the nozzle? It seems like Steve from the dvd mentions someway to compensate if that hole is off centered. Maybe the drill thing I was thinking of had something to do with that? I'm not sure though, it's been awhile since I've watched it. I think that maybe my mistake Mark, I was thinking there was a way to keep them from binding in the nozzle.

Sorry for any bad advice.

 

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3 hours ago, hatepotholez said:

I did exactly what you are describing. Everything is fine once the pot is screwed down then it starts sticking. I can't remember if I always had this problem with the front carb. 

Good. The needles are fine. The next step is to swap the pots to the alternate carbs and see if the problem moves to the rear carb or stays in the front carb.

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Despite the simplicity of the carbs design, they are actually precision instruments with some very precise dimensions in a couple spots. I'm not completely sure what part you dropped, but if you dropped the dome or the piston on the floor and bent either piece, then I think you're in the market for replacement parts. The clearance fit between those two parts is crucial and if it's not right, it will affect mixture ratio.

If you're sanding parts to get the piston to rise and fall smoothly after dropping something, then the whole "constant velocity" part of your CV carb could be thrown off. :(

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So, I ran the car with no screws attaching the pots. 

Car runs beautifully. I have a pot and piston on order. This should solve the trick. fingers crossed. 

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That was a good idea. I had never thought of running them with out the screws

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Earlier you said that you have a 3 pot. (I'm assuming that means you have three screws holding the suction chamber to the carb body?)

I've not messed with those personally and am wondering...  Does that version have the little epoxy alignment nubbies sticking up into suction chamber to align the chamber to the body? If that's the case, then there's no guarantee that a replacement suction chamber will align correctly onto your existing body. It's a surmountable issue, but something to watch out for.

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Mine have or had rubber nipples to align the dome to the body. I broke them off after watching the DVD. Steve says to loosely tighten the screws and find the smoothest spot then tighten them down. Ignoring those things. He says most are gone anyway if they've been apart.

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2 hours ago, Patcon said:

That was a good idea. I had never thought of running them with out the screws

Thanks!

1 hour ago, Captain Obvious said:

Earlier you said that you have a 3 pot. (I'm assuming that means you have three screws holding the suction chamber to the carb body?)

I've not messed with those personally and am wondering...  Does that version have the little epoxy alignment nubbies sticking up into suction chamber to align the chamber to the body? If that's the case, then there's no guarantee that a replacement suction chamber will align correctly onto your existing body. It's a surmountable issue, but something to watch out for.

Yes, I have those. It was suggested before to remove those alignment tabs. I would prefer not to do this until I am out of choices.

1 hour ago, siteunseen said:

Mine have or had rubber nipples to align the dome to the body. I broke them off after watching the DVD. Steve says to loosely tighten the screws and find the smoothest spot then tighten them down. Ignoring those things. He says most are gone anyway if they've been apart.

Were you also having sticking issue with the piston and damper?

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I honestly don't know, I watched the DVD a couple of times then rebuilt the two carbs.  They were original to the car and it had been sitting for 10 years.  During the rebuilding I found the nozzles weren't dropping down and the float chambers were crudded up, the float valves were sticking too.  Now they're nice and shiny and work like new (I'm guessing-I was 3 years old when they were new). :)

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