Gary Lewis Posted January 9, 2018 Share Posted January 9, 2018 If everything else is still the original, specifically timing, you would need to lean the main jet slightly. That being said, first I would look at the plugs and second if it needs "tweaking" there should be a small aluminum plug, like a miniature freeze plug in the top of the carb where the air filter sits (BTW, that air filter is cute, but even for a one barrel is too small), under that plug is a hole down to the small Philips head screw on the metering rod hanger, clockwise is richer, counterclockwise is leaner. Since the YF metering rod is similar to the older carburetors it has both a vacuum and mechanical control. At cruise the mechanical linkage limits the down travel so the mixture is partially dependent of throttle opening. Bill - That's exactly the kind of info I was looking for. Instead of you writing a "book", how 'bout writing a page on tuning YF's? I can put it on the website on the current YFA page, but put the existing info on rebuilding in one tab and your "tuning" writeup in another tab. Link to comment Share on other sites More sharing options...
85lebaront2 Posted January 9, 2018 Share Posted January 9, 2018 Bill - That's exactly the kind of info I was looking for. Instead of you writing a "book", how 'bout writing a page on tuning YF's? I can put it on the website on the current YFA page, but put the existing info on rebuilding in one tab and your "tuning" writeup in another tab. Ok, but I will let you set up the tabs, maybe for all the carburetors? I can even speak VV if needed. Link to comment Share on other sites More sharing options...
Ford F834 Posted January 9, 2018 Author Share Posted January 9, 2018 If everything else is still the original, specifically timing, you would need to lean the main jet slightly. That being said, first I would look at the plugs and second if it needs "tweaking" there should be a small aluminum plug, like a miniature freeze plug in the top of the carb where the air filter sits (BTW, that air filter is cute, but even for a one barrel is too small), under that plug is a hole down to the small Philips head screw on the metering rod hanger, clockwise is richer, counterclockwise is leaner. Since the YF metering rod is similar to the older carburetors it has both a vacuum and mechanical control. At cruise the mechanical linkage limits the down travel so the mixture is partially dependent of throttle opening. Awesome info., thank you Bill! That air cleaner was an emergency solution from when my '68 broke down on the side of the road and I bought that junkyard carb to get it home. It is indeed horrible and causes a noticeable loss of power. I now have one of the large flat style straight six air cleaners on it that David sent me. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 9, 2018 Share Posted January 9, 2018 Ok, but I will let you set up the tabs, maybe for all the carburetors? I can even speak VV if needed. You just send me documents, in pdf or Word, and I’ll set up the tabs and do all the website work. Thanks! Link to comment Share on other sites More sharing options...
85lebaront2 Posted January 10, 2018 Share Posted January 10, 2018 Awesome info., thank you Bill! That air cleaner was an emergency solution from when my '68 broke down on the side of the road and I bought that junkyard carb to get it home. It is indeed horrible and causes a noticeable loss of power. I now have one of the large flat style straight six air cleaners on it that David sent me. Looks good! Glad I could help you with it. Link to comment Share on other sites More sharing options...
Ford F834 Posted February 8, 2018 Author Share Posted February 8, 2018 Awesome info., thank you Bill! That air cleaner was an emergency solution from when my '68 broke down on the side of the road and I bought that junkyard carb to get it home. It is indeed horrible and causes a noticeable loss of power. I now have one of the large flat style straight six air cleaners on it that David sent me. This morning I filled up the truck and got my first unloaded mpg calculation. Unloaded, yes, but the day that I drove it to work it decided to snow. So about 75% was through slush and powder, about 50% in 4wd with the hubs locked in. Speed was about 62 below snow line, then decreasing to 25 in places. I measured 153.0 miles with the gps and 10.17 gallons of fuel calculating out to 15.04mpg. Not bad. I will say that with the hubs locked in for snow the front end was getting noisy around 45mph. It works fine for now and for what I need it for but will need attention at some point. I am driving the truck to work tonight, and will pick up my Diesel engine block from the machinist in the morning. We will see what the next run will return for mileage... being higher speed but no snow. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 8, 2018 Share Posted February 8, 2018 This morning I filled up the truck and got my first unloaded mpg calculation. Unloaded, yes, but the day that I drove it to work it decided to snow. So about 75% was through slush and powder, about 50% in 4wd with the hubs locked in. Speed was about 62 below snow line, then decreasing to 25 in places. I measured 153.0 miles with the gps and 10.17 gallons of fuel calculating out to 15.04mpg. Not bad. I will say that with the hubs locked in for snow the front end was getting noisy around 45mph. It works fine for now and for what I need it for but will need attention at some point. I am driving the truck to work tonight, and will pick up my Diesel engine block from the machinist in the morning. We will see what the next run will return for mileage... being higher speed but no snow. That's good MPG for those conditions. And I suspect it'll be more like 17 when you get a good reading w/o the adverse conditions. As for the front end, check out the u-joints - both in the drive shaft as well as the axle shafts. The axle shaft ones are a bear to change, but can cause noise. Try leaving it in 2Hi and locking in one hub to check for noise. Then swap to the other hub to see if anything changes. Or, go to 4Hi and leave the hubs unlocked. Link to comment Share on other sites More sharing options...
Ford F834 Posted February 9, 2018 Author Share Posted February 9, 2018 That's good MPG for those conditions. And I suspect it'll be more like 17 when you get a good reading w/o the adverse conditions. As for the front end, check out the u-joints - both in the drive shaft as well as the axle shafts. The axle shaft ones are a bear to change, but can cause noise. Try leaving it in 2Hi and locking in one hub to check for noise. Then swap to the other hub to see if anything changes. Or, go to 4Hi and leave the hubs unlocked. Thanks Gary. The front driveshaft u-joints are new, and the slip yoke is solid so it has to be the axle shafts 😔. With the hubs locked in I hear it in both 2Hi and 4Hi. It needs upper ball joints also. I was not able to get them to move in my driveway, but the guys at the tire shop pried with a long bar against the concrete floor and showed me the play... barely any on the passenger side but noticeable on the driver side. I just can't do a full rebuild on it at this point. Yeah it has some wear but it's still useable I am still having some carb issues. It starved out once on the snow day going downhill at 73 mph. (Fastest I have ever pushed it since I've owned it... and no that wasn't in the snow!). It did it again on my way to work tonight after a coffee stop just as I got it going in 4th gear. I guess I will do the solvent dunk + carb kit and hope that takes care of it. With my current timing and tune up the truck feels the best on the highway running 62-64mph. My tach is reading right about 2,000 + change which is reasonably accurate. Pulling the mountain grades I hold 52-55 mph in 4th just letting it do its thing without flooring it. The grades include some pretty long stretches at 6%. Pretty tame straight six stuff, I know, but a bench mark for later reference as I work at tuning it up. I hear no pinging or knocking, fuel is 87 octane regular. Verde valley is ~3,200' climbing to just over 7,000' near my job. Perhaps I can squeeze just a bit more out of it 😉 Link to comment Share on other sites More sharing options...
1986F150Six Posted February 9, 2018 Share Posted February 9, 2018 Thanks Gary. The front driveshaft u-joints are new, and the slip yoke is solid so it has to be the axle shafts 😔. With the hubs locked in I hear it in both 2Hi and 4Hi. It needs upper ball joints also. I was not able to get them to move in my driveway, but the guys at the tire shop pried with a long bar against the concrete floor and showed me the play... barely any on the passenger side but noticeable on the driver side. I just can't do a full rebuild on it at this point. Yeah it has some wear but it's still useable I am still having some carb issues. It starved out once on the snow day going downhill at 73 mph. (Fastest I have ever pushed it since I've owned it... and no that wasn't in the snow!). It did it again on my way to work tonight after a coffee stop just as I got it going in 4th gear. I guess I will do the solvent dunk + carb kit and hope that takes care of it. With my current timing and tune up the truck feels the best on the highway running 62-64mph. My tach is reading right about 2,000 + change which is reasonably accurate. Pulling the mountain grades I hold 52-55 mph in 4th just letting it do its thing without flooring it. The grades include some pretty long stretches at 6%. Pretty tame straight six stuff, I know, but a bench mark for later reference as I work at tuning it up. I hear no pinging or knocking, fuel is 87 octane regular. Verde valley is ~3,200' climbing to just over 7,000' near my job. Perhaps I can squeeze just a bit more out of it 😉 That sounds good, Jonathan, except for the fuel starvation issue. The Frenchtown Flyer has in previous threads, indicated that with the aerodynamics of this body, the fuel consumption significantly increases after 62 mph. I get my best mileage @ ~60 mph. My son's truck gets its best @ ~65 mph. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 9, 2018 Share Posted February 9, 2018 Thanks Gary. The front driveshaft u-joints are new, and the slip yoke is solid so it has to be the axle shafts 😔. With the hubs locked in I hear it in both 2Hi and 4Hi. It needs upper ball joints also. I was not able to get them to move in my driveway, but the guys at the tire shop pried with a long bar against the concrete floor and showed me the play... barely any on the passenger side but noticeable on the driver side. I just can't do a full rebuild on it at this point. Yeah it has some wear but it's still useable I am still having some carb issues. It starved out once on the snow day going downhill at 73 mph. (Fastest I have ever pushed it since I've owned it... and no that wasn't in the snow!). It did it again on my way to work tonight after a coffee stop just as I got it going in 4th gear. I guess I will do the solvent dunk + carb kit and hope that takes care of it. With my current timing and tune up the truck feels the best on the highway running 62-64mph. My tach is reading right about 2,000 + change which is reasonably accurate. Pulling the mountain grades I hold 52-55 mph in 4th just letting it do its thing without flooring it. The grades include some pretty long stretches at 6%. Pretty tame straight six stuff, I know, but a bench mark for later reference as I work at tuning it up. I hear no pinging or knocking, fuel is 87 octane regular. Verde valley is ~3,200' climbing to just over 7,000' near my job. Perhaps I can squeeze just a bit more out of it 😉 Yes, the aerodynamics are worse than a proverbial barn door as these trucks have recesses, like headlights, that capture the air. That's why Ford flushed them in '87. Could your fuel problem be icing? Do you have heat plumbed to the air cleaner? As for timing and tune, have you ever had pinging? If not, you probably don't have enough advance dialed in. I think we've talked about that before, but best MPG is going to be just short of pinging. And that occurs at part-throttle, which means you need to adjust the vacuum advance. Link to comment Share on other sites More sharing options...
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