67.5. 1600. Carb issue

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Gregs672000
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Re: 67.5. 1600. Carb issue

Post by Gregs672000 »

Bajaroadster, my suggestion as always is to be systematic in your approach. You have done well to read up on the carbs and how they work. What you have is a graduated or tapered needle that sits into a nozzle (basically a tube with a hole in it that delivers fuel to the carb) that increases in flow when the vacuum from the engine causes the carbs piston to raise, thus pulling up the needle which progressively feeds more fuel to the engine since the needle is tapered. The taper of the needle determines the overall air to fuel ratio. At idle the needle is sitting in the nozzle which allows little fuel to get past it. By adjusting the knob or dial on the nozzle you are changing the position of the nozzle on the needle by raising or lowering it, thus changing the amount of fuel, both at idle and then as the vacuum causes the carbs piston to raise and expose more space around the needle while you drive. Tighten it and you lean, loosen and you richen.

Your back carb is rich. That can be due to a sunk float (pushes fuel past the needle due to increased pressure that is not being regulated by the needle and seat via the float) so check that. Carbs airflow must be equal, so a unisyn or similar carb flow meter is required (get a "Snail" version if you don't already have a tool) and make sure they are the same (if you struggle here we'll discuss carb linkage so you can adjust). Then the nozzle adjustment needs to be equal for both carbs. I won't discuss adjustment at this moment because you have probably already read about it, but it's important to understand that when you're disabling one carb at idle (pushing up the plunger underneath the carb) you're checking the air/fuel ratio on the OTHER carb. When you push up the plunger on one carb to test the other carb, idle should raise up for a second then drop, with the engine acting like it's running on two cylinders but not dying. I might try leaning it until it dies while testing, then adjust it a 1/4 turn richer until it continues to run while testing, then do the same to the other carb and see how it runs. Backfiring through the carbs while driving is too lean (white plugs), black of course is too rich and the car is boggy. Continue to adjust as needed. If you're unable to adjust it or lean it out then there may be worn parts that need attention.

Hope this helps!
Greg Burrows
'67 2000 #588
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bajaroadster
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Re: 67.5. 1600. Carb issue

Post by bajaroadster »

Thanks Greg. The confirmation that pushing the plunger on one carb is checking the other carb is helpful, as several of the tutorials ive read or watched do not address that fact. I tried the low tech version of testing air flow with a length of garden hose yesterday and honestly could not detect a difference.Either they are reasonably close or my old man hearing isnt sharp enough to be any help. Its to the local parts store today to see if I can purchase or order a carb flow meter of some sort.
Is Gordon Glasgow still up in your neck of the woods?
Ive seen normal. It aint pretty.
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Gregs672000
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Re: 67.5. 1600. Carb issue

Post by Gregs672000 »

Yes on Gordon, but I have not seen him in about a year with COVID and all. The garden hose method is crude at best, and just a small difference in flow will make them not run right. Both the unisyn and the Snail are listed on amazon if you want to see them. The difference is the Snail does not block airflow so you can hold it on the throat and check things more easily, while the unisyn is momentary and will drop flow if you hold it over the carb for long.
Greg Burrows
'67 2000 #588
Tacoma, WA
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Re: 67.5. 1600. Carb issue

Post by bajaroadster »

A trip this morning to the local Autozone (yes, we actually have one here) was fruitless. Not in stock and nothing in all of the stores in Baja to have one shipped even though the Edelbrock unisyn shows up on their website. Welcome to Mexico. I will have to wait until I have a friend travelling this way that can bring me one. Amazon does have a presence in Mexico, but ALOT of things normally available from them are not in country and the cost to ship them internationally is cost prohibitive. Going to check with my local mechanic to see if he possibly has one. Until then...........
Greg, hooked up with Gordon some 30 years ago when I was visiting some friends in Tacoma. If I remember correctly, he also was driving a black 67 2000 at the time.
Ive seen normal. It aint pretty.
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Gregs672000
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Re: 67.5. 1600. Carb issue

Post by Gregs672000 »

Yep! Gordon was the first Roadster owner I ever met. I can still remember calling him the first time. When I told his wife JoAnne that I had a 67 2000 she just about dropped the phone, and seconds later Gordon was on the phone "Hello! Hello! You have a 67 2000!" He and a buddy came over the next day and his beautiful black 67 2000 (431 i think?) was the first I'd ever seen up close other than my rust bucket. Total inspiration. I was so sad to hear it had been hit on the way home from Shasta several years back I think it was, but it's fixed and waiting on an engine I think. Gordon came through for me recently 2 years ago with a replacement block and crank after I buggered up mine.

If I still had my unisyn I'd send it to you. Any idea what the shipping would be to You? Someone could buy one here and send it on to you, or send one to borrow maybe?
Greg Burrows
'67 2000 #588
Tacoma, WA
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Re: 67.5. 1600. Carb issue

Post by unklpat »

Why don't you figure out what other small parts you might need, and I'll find out what max weight for the minimum shipping costs might be to get them to you. I'll need your address. Pat
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Re: 67.5. 1600. Carb issue

Post by bajaroadster »

Greg and Pat. Very much appreciate your offers. Ive been here almost 4 years now and have explored all the options for shipping here. Really no way around the crazy fees to move things across the border. I was so spoiled by living in the states and having almost anything showing uo at my door with a few clicks that it was very frustrating to no longer have that option. Ive accepted that one of the downsides to living in paradise is that things are not as convenient here sometimes. A small price to pay, and a good lesson in patience. It has made me creative in finding alternate solutions. I am retired and have plenty of time. I have several friends that visit from the states and several friends that live here that visit the states on a fairly regular basis. I just have things shipped to them in the states and they bring the items with them. The additional charges for shipping across the border can sometimes double the cost. So, I will be able to purchase one and have it here before to long. And in the meantime, the car is running well enough to enjoy it still, and there is always something else to tinker with.
Greg, tell Gordon hello for me next time you run across him.
Ive seen normal. It aint pretty.
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spl310
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Re: 67.5. 1600. Carb issue

Post by spl310 »

Bajaroadster - if there are any air cooled volkswagen specialists in the area - see them about the Unisyn.
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unklpat
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Re: 67.5. 1600. Carb issue

Post by unklpat »

I could mail you my "just SU" dvd from Z-therapy. You would have all the instruction you need. Find a Unisyn to borrow, and all good. Pat