T.Colucci Posted August 21 Share Posted August 21 Greetings all. New to the Franklin world, new to the forum. I inherited a 1928 Franklin 12A Coupe from my father, and am diving right into it - fully intending to learn the car bumper to bumper. Already have an issue - car will start but will not stay running and I suspect the carburetor. I have verified the vacuum pump is OK, but did clean, and ultimately remove an inline filter between the tank and the carb - it was filthy, choked up with several years of dry AZ dust. One I did that the car went from not starting at all, to starting, idling (a bit slow), then stalling out - consistently. So I have reason to think that the bowl is probably full of mud? The carb is not the original Stromburg T2 though, so I'm hoping that I could get some feedback on the existing unit. I have not taken it out yet, but so far cannot seen any plate or other lettering. The car ran beautifully with this carb so it is certainly appropriate to the vehicle - and I'm looking for any information on make / model if it looks familiar. I have never taken a carb apart, so you can understand if I'm hesitant to just crack it open without some kind of documentation. Any help would be greatly appreciated. 1 Link to comment Share on other sites More sharing options...
carbking Posted August 21 Share Posted August 21 Looks like a Stromberg U-2, which would be correct for late 1928. Jon 1 Link to comment Share on other sites More sharing options...
SparksNArcs Posted August 21 Share Posted August 21 If the car has been sitting for a long time, the carburetor probably has old gas in it that has turned to varnish. To get it running well you'll need to take the carb apart and thoroughly clean it, blow out all the jets and passages, and put a new set of gaskets in it. Pfitz on here knows his way around Franklin carburetors, I'd get in touch with him for help. 2 Link to comment Share on other sites More sharing options...
T.Colucci Posted August 22 Author Share Posted August 22 On 8/20/2024 at 10:27 PM, carbking said: Looks like a Stromberg U-2, which would be correct for late 1928. Jon Spot on - a bright flashlight and a mirror confirmed U-2. The carburetor, not the band. Now to find some technical documents. Link to comment Share on other sites More sharing options...
PFitz Posted August 22 Share Posted August 22 Welcome TC. Yes, it's a Stromberg U-2, but a cast iron one. An excellent carburetor!!!!! Your '28 would have had a Stomberg T-2 on it originally, but being early pot metal most T-2 have cracked /crumbled to bits. Franklin first used the cast iron U-2 in late '29 Series 13 after realizing problems with the Stromberg pot metal T-2 that was used in '28 and early '29, then the pot metal U-2 of mid '29 production. So, the cast iron U-2 were only used the last few months of '29 production and as such are very rare by now because most that ended up as spares have been grabbed to replace the earlier pot metal carbs - as yours was. Next question is which size U-2 ? Franklin used two sizes matched to their two engine sizes in '29. Both look identical from the outside, but the venturi, jets, and restrictions differ. Put a 135/137 size U-2 on a 130 or Series 12 and it becomes lethargic because the venturi is too big for that smaller engine. Put a 130 U-2 on a 135/137 engine and it runs great but loses some top speed. Been there done the road tests. They are rebuildable and when properly rebuilt they are terrific, but it takes much more than just putting in a "kit" to make them run at their best and not damage the engine. Here's what they look like restored with the correct nickel plating. Paul 3 Link to comment Share on other sites More sharing options...
T.Colucci Posted August 23 Author Share Posted August 23 Paul - thank you for that great information. I'd run through some of the issues above, and based on what I've seen there is a good chance that sediment has gotten into the carb. There was an in-line filter in the place where that tubing is and it was extremely dirty - it has since been removed. There is adequate fuel flow into the carburetor, and the car will now start and idle for a short time now before dying out where before it might start once, and then fizzle out entirely. I have not been able to fully test the vacuum tank, but it was drawing fuel and while the car was running I could see fuel swirling in the gascolator. I'd like to open up the carb and inspect & clean it but am hesitant to do that without having replacement seals and an idea of critical elements to be looking out for. I'll probably scare folks here with this, but I am very dedicated to learning and understanding the parts of the car and would like to carefully do the initial cleaning myself. Hopefully it's as simple as AZ dust clogging up the intakes or float. What guidance can you give that won't be too "dangerous" for a rank amateur to get into that would get me though the basic first steps? Adjustments would be another good topic as there are multiple needles & valves - I have pulled up the Stromburg U-Series manual on the Franklincar web page. The car was my Father's, and it's something I intend to keep as long as I live - so I'm already completely sold on keeping it in top condition and starting to restore it from a PR Driver into a near original condition driver. It's not going to be a garage queen - not by any stretch of the imagination. Link to comment Share on other sites More sharing options...
PFitz Posted August 23 Share Posted August 23 (edited) Very nice coupe. It takes more than just having the parts to rebuild it, such as are sometimes in a kit. You'd need the special tools to not cause damage, plus the special equipment needed. And then you'd need the experience to know what needs to be checked to make sure it has all the right parts, in the right place, and how to deal with 90+ years of who knows what wear, damage, and/or who has fiddled with it and "inflicted" it with their idea of repairs. Not to insult anyone, but about 30 years ago I tried the kit route and gave it up because I got fed up with the frustration and hassles associated with trying to teach a rather complex job, that needs specialized tools and equipment to be able properly rebuild a carb beyond just a cleaning and putting a kit in. Rinsing out and installing a kit in a carb like your U-2 that has over 130 parts is only half the job. About 50% of my work is fixing what others have already "fixed" and done wrong,.... including by supposedly professional shops. Just in the past year I've had to rebuild several Franklin carbs that owners thought they had rebuilt, or they had paid a carb shop to rebuild, but none could run an engine and two had fuel pouring out risking a fire. Paul Edited August 23 by PFitz (see edit history) 1 Link to comment Share on other sites More sharing options...
Steve Braverman Posted August 23 Share Posted August 23 Paul rebuilt the U2 in my 147 last year. He is highly recommended. If you have not already done so, join the HH Franklin Club. It is an amazing group. 2 Link to comment Share on other sites More sharing options...
PFitz Posted August 23 Share Posted August 23 (edited) Thank you, Steve. FYI, your '30 has the U-3,.... the big brother of the U-2. Very similar, but larger in every respect for the redesigned higher horsepower and greater compression of the '30 and later engines. Your engine would run great until it topped-out at about 45-50 mph with that smaller U-2. Maybe that's not such a bad idea for some owners with a heavy right foot. 😁 Paul Edited August 23 by PFitz (see edit history) 1 Link to comment Share on other sites More sharing options...
T.Colucci Posted August 25 Author Share Posted August 25 On 8/23/2024 at 11:39 AM, Steve Braverman said: Paul rebuilt the U2 in my 147 last year. He is highly recommended. If you have not already done so, join the HH Franklin Club. It is an amazing group. HI Steve - that's the very first thing I did, then I ordered the 1928 owners manual, and printed out the Stewart Vacuum Tank manual. Great site, great people! So - today I checked the distributor, ignition coil, polished everything up and made sure it was seated correctly and everything had contact & good spring tension. The condenser looks like it's pretty new but I was thinking about just putting a new one in for process of elimination. Paul recommended checking the valves (per the manual) so I've got that on my agenda. Still the same, started it this AM after checking, ran for a bit - although I had to keep feathering the choke, but ultimately stopped. While it ran it was smooth - no backfires, so "maybe" I don't have any issues with ignition timing. Still seems to be fuel related, but I'm sure that eliminating everything else I can is the most valuable task. Of course, I know precisely bumpkus about antique car engines so my "experience" is reading everything I can about engine issues and pouring over the owners manual to glean anything I can! Gotta' start somewhere. Link to comment Share on other sites More sharing options...
carbking Posted August 25 Share Posted August 25 If it ran for awhile and then quit, check out the fuel delivery system before throwing rocks at the carburetor There still may be a carburetor issue, but the engine will not function normally if there is insufficient fuel in the carburetor. And while I manufacture the carburetor rebuilding kits, I agree completely with Paul about kitting versus professional rebuilding on the Stromberg U series. The majority of post WWII downdraft carburetors can generally be rebuilt by an avid hobbyist (there are exceptions to this), with a kit for a starting point, and normal mechanic's tools. Many earlier carburetors, including the Stromberg U series, scream for a professional WITH EXPERIENCE ON THAT SERIES and the special tools! The ideal situation would be to reside sufficiently close to the professional, and watch the professional at work. There is a LOT to be said for the old system of apprenticeship. Jon 5 Link to comment Share on other sites More sharing options...
T.Colucci Posted August 25 Author Share Posted August 25 (edited) 4 hours ago, carbking said: If it ran for awhile and then quit, check out the fuel delivery system before throwing rocks at the carburetor There still may be a carburetor issue, but the engine will not function normally if there is insufficient fuel in the carburetor. Jon - I still have the Stewart Vacuum tank. I have made sure that there are no blockages in the vent tube, the tube to the manifold is clear, Gascolator is clean and clear, and I disconnected the fuel line below the petcock and dumped a good part of the tank, then refilled it from the top (replicating the "limp home" method mentioned in the owners manual). The mechanisms all appear to be in good working condition, and I ran a pipe cleaner through the gas line from the vacuum tank to the carburetor. That should rule out blockage at least. I know it won't completely rule out a vacuum leak if that could be another possibility. I did something a little different today - I opened the petcock and left it for a couple hours, then went out and started the car. Fired right up, and once got going I was able to close the choke. Initially it was a bit choppy and I got a small backfire once, then it smoothed out. I added throttle so it was running at what I would guess to be around the 20mph range and I let it go. I It ran for just shy of two minutes and then sputter, sputter, stall. Let it sit for about 15 minutes and then did the same thing, but this time only got about 45 seconds. Would it stand to reason then that it likely burned through the fuel that was was in the bowl and what was coming in through the fuel line - but ultimately starved out because not enough is getting through the carb? The fact that it starts so readily and runs should rule out the electrical system. I'm still going to check my valve settings too though. (0.010 gap!) That's pretty well explained in the owners manual - although I do have to figure out turning the motor over by hand and make sure I have the right tool for that. Edited August 25 by T.Colucci spelling (see edit history) Link to comment Share on other sites More sharing options...
carbking Posted August 25 Share Posted August 25 Someone with more experience with vacuum tanks needs to jump in here. In the meantime, guessing you maybe have a vacuum lock on the tank??? Also possible the fuel valve in the carburetor is not functioning normally. Something in the fuel delivery system seems haywire. Jon Link to comment Share on other sites More sharing options...
PFitz Posted August 26 Share Posted August 26 (edited) If the vac tank is functioning properly, you will hear the rpm drop slightly as it cycles on and starts drawing fuel from the gas tank. Then you will see some bubbles and turbulence in the Gascolator's glass sediment bowl that is attached to the side of the vac tank top casting. The bubbles don't necessarily mean an air leak. Some air gets trapped up in the top of the Gascolator bowl area and gets stirred around as fresh gas pours in. When the vac tank stops cycling the air bubbles go back up to be trapped in the top of the sediment bowl area. If there actually is an air leak - most commonly because the pot metal casting of the Gascolator top warps - the sediment bowl will go empty. I can fix that kind of leak. If the fuel lines are clear, and the sediment bowl looks like it stays full, and the car always starts with the choke handle pulled out but then quits when the choke handle is pushed in, the problem is most likely not the vac tank but the carb. However, If you wish, when you bring the carb, bring the vac tank also. I can check the vac tank and Gascolator and rebuild if needed. Paul Edited August 26 by PFitz (see edit history) Link to comment Share on other sites More sharing options...
hchris Posted August 26 Share Posted August 26 FWIW, just to add to the above. As well as looking for a rev drop when the vac pump kicks in, with your hand on the fuel inlet pipe to the vac tank, you'll feel a temperature drop as the fuel flows in. Link to comment Share on other sites More sharing options...
PFitz Posted August 26 Share Posted August 26 10 hours ago, hchris said: FWIW, just to add to the above. As well as looking for a rev drop when the vac pump kicks in, with your hand on the fuel inlet pipe to the vac tank, you'll feel a temperature drop as the fuel flows in. This could be misleading for knowing if the vac tank is working or not. Franklins have the exhaust system running parallel and inches away from the fuel line all the way back to the gas tank, so not likely to feel any temp change as fuel flows in. However, the fuel line on a 27 comes right into the Gascolator attached to the outboard side of the top casting of the vac tank. The turbulence of gas going into the glass sediment bowl, and the few trapped bubbles it causes to swirl around, is easily visible when it is drawing fuel. Paul Link to comment Share on other sites More sharing options...
T.Colucci Posted September 2 Author Share Posted September 2 Update on the Franklin. Our friend Matt Green called and we talked about the problems I was having. Went out to the car and went over the entire fuel delivery system in extreme detail - vacuum lines, vent lines, etc... Hopped in, hit the starter, and it fired up immediately and started idling, then running at throttle smoothly. So that's the good news. Drove it around the block and just coming up to the driveway it started surging, and pulling in, it stalled out again - but this time I know why. The Gascolator and the in-line filter to the carburetor (which Matt firmly instructed me to re-install) are full of sediment, more directly - choked up foul with sediment. It appears my problems are linked to a very dirty fuel tank and sediment in the lines. A full cleaning from the tank all the way up to the carb is in order, and I'll likely install a fuel filter coming out of the tank. Also on the positive side - now I know for sure that the vacuum tank is drawing, because the Gascolator was clear earlier, that sediment could only have come in from the tank. All things I really could not figure out without getting it running again, at least for a little while. Another day, another adventure. Recommendations - drain and flush, or don't take chances and remove and professionally clean? If it's AZ dirt and dust the hope is it will flush out. If it's rust and a bad tank, I should be able to figure that out with a snake camera along with the necessity of continually having to change out the fuel filter. Fingers crossed that the carburetor is not hopelessly fouled, but with Paul only a hop and skip away from where I live, at least that's only a bit of time and money well spent. Link to comment Share on other sites More sharing options...
PFitz Posted September 3 Share Posted September 3 Whatever crude and rust are in the tank should be properly cleaned out. Best to have it cleaned and sealed or the rust will continue- especially if you use gas with alcohol. And whatever crude is coming loose in the tank is also coating the inside of the fuel line - which is easier to replace than try to clean as a tank. Also need to remove the fuel pickup/sender unit and inspect it for the brass deteriorating. I recommend that you don't try to remove the drain plug. The threads rust in place and to break the rust loose too often takes more than the solder joints can withstand. Seen it happen many times. Odds are that carb will need professional cleaning. Just rinsing or soaking in solvents won't clean the small internal passages. Paul 1 Link to comment Share on other sites More sharing options...
T.Colucci Posted September 3 Author Share Posted September 3 (edited) Thanks Paul - not unexpected to read that. Cheaping out on an antique might keep it running................ For now. Fuel gauge is not working regardless, so that was a known project that will become that much easier by addressing the system as a whole. Oh - and absolutely not on gas with alcohol unless no other choice. Dad insisted on non-ethanol fuel and he likewise drove and worked on antiques for years. I'm taking that advice to heart. Edited September 3 by T.Colucci (see edit history) Link to comment Share on other sites More sharing options...
PFitz Posted September 3 Share Posted September 3 11 hours ago, T.Colucci said: Thanks Paul - not unexpected to read that. Cheaping out on an antique might keep it running................ For now. Fuel gauge is not working regardless, so that was a known project that will become that much easier by addressing the system as a whole. Oh - and absolutely not on gas with alcohol unless no other choice. Dad insisted on non-ethanol fuel and he likewise drove and worked on antiques for years. I'm taking that advice to heart. The fuel gages rarely work. Many owners switch to using a "splinter gauge" - a wooden stick that should be too long to fall inside the tank. I've found a few of the too-short type inside tanks. What sometimes rots out is the fuel pickup tube. Came upon a Series 10 dead on the side of the road during a Franklin Trek. No gas getting to vac tank but gas tank half full. Vac tank check good and I could not find any leaks in fuel line. Had a gas can with me so we put in a gallon, After a bit of cranking it pulled fuel fine and started up. Turns out the pickup tube in the tank was rotted through about halfway up. Could only run on fuel in the top half of the tank. Paul Link to comment Share on other sites More sharing options...
carbking Posted September 3 Share Posted September 3 First time I have heard the term "splinter gauge". We used to cut down a wooden yardstick, so we would have the measurement of how deep was the fuel. Jon Link to comment Share on other sites More sharing options...
PFitz Posted September 3 Share Posted September 3 (edited) 37 minutes ago, carbking said: First time I have heard the term "splinter gauge". We used to cut down a wooden yardstick, so we would have the measurement of how deep was the fuel. Jon Jon, over the years I've cleaned and sealed many tanks. Found a few branches, twigs, and paint stirring sticks in the tank because they were short enough that if grip was lost, they fit completely in. I've made a few "splinter gauges" for customers that didn't want to get involved with having to drop the tank to rebuild the gas gauge systems. The wooden gauges are made out of 1/2 inch wooden dowels that I stamped with 1/4 tank increments. But I always leave them too long to get lost inside the tank. 😉 Paul Edited September 3 by PFitz (see edit history) Link to comment Share on other sites More sharing options...
carbking Posted September 3 Share Posted September 3 Paul - at one time I had a "factory" one with the Ford logo; don't know if it was genuine Ford or A/M. Jon Link to comment Share on other sites More sharing options...
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