Motorcraft DOPF?

spikeomatic

Well-known member
Have a stock 200 for my 68 falcon .just upgrading the ignition to Duraspark II ,maybe a header? it came with one of those replacement Holleys DOPF L .is this a carb worth rebuilding?haven't heard much about them?
 
If your carb is the same as the one in the link then I had the same type too. I rebuilt mine I found three stripped threads. Tried to heli-coil them with various success. It was my first time trying. Anyway, I put it on and the car can great. THEN I read and believed the BS from Pony Carb about better gas mileage and improved performance and bought one of their 1 bbls. It was a total POS. It had the choke coil on backwards; hesitated coming off idle; had the same gas mileage, etc. After being insult just one time too many from Pony's owner, Jon, I put the DOPF back on and drove the car for many trouble-fee years.

I like the DOPF style because it has the vac choke pull-off. Had a great idle. Decent gas mileage. Good performance (for a stocker). The only problem I found was trying to find a choke coil and cover for it, never did find one. Mine did have the SCV, which was correct for the stock LoM dizzy on my '65.
 
Howdy Spike:
If your carb is a Service Replacement from FoMoCo then it would be a Holley #1940. The #1940 first appeared in the 1970 year, which further muddies the puzzle. The down side is that the 1940 was a one-size-fits-all replacement for a variety of Autolite 1100s and 1101s that were no longer available. They had SCV and Non-SCVs. Getting the right one, in the right box for the right engine ocassionally happened as intended. In general, they were down on mileage to the OEM carbs. All things considered, I'd be looking for a 1970 and later Carter YF from a 1970 200 engine.

Good luck.

Adios, David
 
thanks all!great info, advice. don't think I'll be spending 400 on a 1bbl anytime soon.what did the carter Yf's come on? what passenger cars? trucks?
 
I got a YF off of a '76 Granada and a '74 Maverick (I think). To be honest with you I've tried both but never got them to idle correctly. It seemed it was way too lean. I'd like to know who has run one and what the idle jet and air bleed sizes are on the ones that run right.
 
Howdy Spike:

after 1970 all Ford 200s got the Carter YF. The last year was 1979. I'd reference on from the early 70s, C8 to D3. You will likely need to modify your linkage or switch to a throttle cable system- not a bad idea anyway. A Carter should run as good as an 1100, and maybe get a little better economy because of the vacuum actuated metering system.

Mugsy- a poor idle sounds like a vacuum leak, ignition problems or a dirty carb. What solved the poor idle quality? YFs are notorious for a weak accelerator pump system, just like 1100s, but are noted for a smooth idle. The vacuum metering system allows them to give pretty good performance over a wide application range.

Adios, David
 
First off not to hi-jack this thread....

Dave,

I've checked extensively for a vac leak using carb cleaner and cannot find one. Along the base, carb seams, throttle shaft penetration, etc.

Also along with the very poor idle it had a miss with the brand new DS-II dizzy (from O'Rielly's) including a new control box etc. Swapped boxes no change; changed volts to coil from 6V to 12 V, no change; new plug wires, no change; changed to new plugs with smaller gap, no change; went back to stock gap in plugs, no change; cleaned interior terminals on cap, no change; disconnected PVC hose and plugged nipple, no change. Finally swapped dizzy to a JY one and the miss went away!!! Still idles like dirt. Finally drilled out the bottom restriction on the idle jet with a drill a few .00X" larger and the idle improved. Drilled the restriction out larger and it got better still. Drilled out the top of the idle jet, that resulted in the very minor improvement. I have also played around with the idle mixture screw and no change. Well actually if it out 1.5 turns it barely runs. I get highest vacuum around 2.5 turns out. I can drive it and stop at traffic lights with it 3 turns out. I also moved the CI adjustable timing chain set from -2* (I was hoping to move the power band up a little in the rpm range) to 4* advanced. Idle got a little better. But again, at traffic lights I have to put it in neutral to keep it idling, in gear it will barely idle. And when out of gear it idles very nicely, only when its in gear does the idle quality go to crap. And finally, during running it runs fine, just the idle while in gear.
 
Howdy All:

Mugs- Wow!! Very thorough. I'm impressed. I'd suggest that you try a different YF. Maybe one from a 240 or a 250 for a slightly richer idle circuit. This isn't usually a problem. Like I say, the YFs were used on a bunch of 200s from 1970 to 1979. Is it possible that your YF was built for a 170? Or a Calif/emmissions 200 from '66 or '67? They were quite lean. Just some thoughts. If IIWIYS, I'd be looking to try a differnt YF to try for comparison.

Adios, David
 
Like I said, I liked my 1940. All around good, functioning carb. Rebuilding is pretty easy and straight forward, esp if you have done carbs before. Mine had several issues, but the only one that I would tell you to watch for is the internal passages to the choke coil. The one on my car was plugged with dirt and crud. There wasn't any vacuum at the coil so the choke didn't warm and pull off. Make sure that's all cleaned. Then follow the instructions on setting all parameters back to factory spec.

Dave- thanks for the compliment. Being Irish AND and an engineer helps :wink: As I said earlier, I'd love to get the idle jet size and air bleed size from someone who has a functioning YF on 200. I have a third one on it and still has idle issues. :bang:
 
Looks good from what I remember mine looked like. Also, see the threads on the warm air feed to the choke. On mine those threads are the same as a 1/4" tube compression fitting. I went to the hardware store and bought a compression union, took the ferrule and nut off, slide them over the end of a 1/4" copper tube and used that. Make sure you put some type of insulation over the choke tube too. The radiator fan creates enough air flow to cool off the choke tube and delays the choke from fully opening.
 
got the carb all rebuilt ,just need a new dash pot?is this really needed? holley/autozoon has a universal one for 37.bucks?
 
From what I've read the dashpot is needed for auto tranny equipped cars. I can't say if its really needed or that mine have worked as designed.
 
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