I'm just here to look a things I did years ago as a young man and maybe to remind myself of just what might need doing once more before my number is up. I bought a car for my 25th birthday. I'm still driving it today. I turn 71 in about 7 months. Excellent to watch these videos and thanks for the memories. Aug 12 2021. Tom T.
It's pretty amazing to me just how much information is available now that you wouldn't have had 50 years ago. Not to mention how easy it is to have cheap parts delivered to your door. Great job keeping it driving! Age is just a number... so long as you can ignore poor eyesight, and a few other quirks.... anyway 70 is young now according to the irs. You have to be 72 before they start making you withdraw retirement funds nowadays. ;) Stay young, and keep that car on the road!
@@midwestmotoringIts the parts I worry about. Once you'd walk into an auto shop and talk with a man about just about anything. Now you walk into a boutique with funky bopping music going and some 'bun boi' serving you and not having a single clue as to what you want and the usual words coming out of their mouths...... "Nah, Can't help ya". I was just setting up some light rubber sheet to be stored in the car as emergency carby diaphragm material. I go out doing a lot of timber cutting in isolated areas and need to be ready for any emergency. That's what brought me here to your videos. Excellent they are too.
I hear you. I'm hanging on to being in my 30s for dear life and I'm already frustrated with people my own age. My favorite question to get is "what kind of car is that for?" They went out of business about the same time AutoZone was founded. You haven't had it in stock in decades. Stop asking that and just let me look at the rolls of heater hose you keep in the back already!
@@midwestmotoring I specifically refuse to go to the parts shop (headbanging music boutique cosmetic gear for sale), in my home town but will drive for an hour to look around at other places. And yep... Every single time no matter where I go comes the usual, "What's it for" with the person whose asking not having a single clue as to what even a 'set of points' means, let alone an oil seal and a 'collapsible spacer for a Salisbury Diff. I need to find a good online parts dealer. LandRovers. Any ideas.
Sadly not. I've heard Atlantic British is decent with tech support on old Land Rover, but haven't had any experience myself. Could be worth checking out.
This is great info for me. Just bought my first 1974 TR6 to totally restore but l wanted to try and start it to see if it runs. Now l will feel a lot better about rebuilding the carburetors! Thanks! Dave in AZ
The TR6 is a great car to restore. The separate chassis means you can get a really good look at every square inch and separate the jobs to be done. Just take your time with the restoration and don't get discouraged. Good luck!
Excellent explanations! Many Thanks! I disassembled the temp compensator because it was stuck. After 50 years, both the plastic pin was rough and the socket slightly oxidized. I stretched a small rag into the cordless screwdriver and polished the bushing bright with aluminum polish. I did the same with the pen. Now nothing is stuck.
I have another section of questions about my choke - I am "lucky" enough to have a Series II XJ6C that has the water choke system. I have taken it apart and am cleaning it up, but there is a screw hole on both carbs that looks like an adjustment screw but is missing the screw. should there be a screw here? In general, are these chokes any good and, if not, should I just convert it over to an old style choke and bypass the coolant lines? According to my father in law, these chokes have never worked well at all. Thanks again!
Yeah, I'm not a super big fan of the water chokes, though if I'm being honest it's partly because I don't have them in my cars so I'm just less used to them. Triumph had a sort of auto choke they used on the TR7 which was more or less a separate carburetor bolted where the choke goes. It works fairly well, but I'm not sure it'd fit on your Jag or if the one on the XJ6 is that same system. In truth, if there's a kit for a manual choke it wouldn't hurt to put that on as it'd be more reliable and remove a potential leak spot (that is, unless you're going for originality).
Got it - seems to me to be very complicated and not really doing much to make things better. The Jag Chilton's guide has some info on setting/adjusting it, but I think they have the parts diagramed wrong as you can't actually do what they say to do. Going to just do the rebuild as is and see what we get, but at some point may pull the motor to clean up the engine bay and could do a manual choke kit then (if I can find one). Thanks again!!
Most parts on these carbs can be made operational by simply cleaning them. I don't find they much needs to be adjusted except for the float height and the needle/jet.
On the bypass valve, didn’t you say in the previous video that it had a vacuum leak where that external screw was? How did you fix that? Did the new diaphragm fix it?
In that case I fixed it using a different bypass valve I had laying around. Generally though, cleaning the surface, replacing the o ring, and using a sealant are what I would do.
@@midwestmotoring thank you for responding. I thought about using a sealant actually. I’m not sure if the O-ring is in my rebuild kit or not. I guess its in the bypass valve rebuild kit, which is separate. I do have a large assortment of new O-rings though, and I bet one would probably fit.
Most likely. I've found the orings themselves just do a poor job sealing. I set up bypass valves for a given amount of vacuum, so once set I usually just seal the end before reassembly to prevent it leaking.
My bypass valve has the external vacuum tube as well as the screw adjuster. I’ve mistakenly taken the entire valve part and cleaned it. I set it to where the other carb bypass is set and it does work when a vacuum is applied. The question is, is there an adjustment once the car is running?
Hello!! Thank you for these videos - without them I would be lost!! Question on the bypass valve - the kit for this has 5 gaskets and when I took mine apart per your instructions, there was a gasket, the diaphram, and then another gasket. In this video you take it apart and there is just the diaphragm and then you put it together with just the diagram. Which way is correct? If as you did it, how come there are so many duplicate gaskets? Thanks in advance!!
Great question! It's a kit meant to suit different variants, so there's a bunch of gaskets and o rings you may or may not need. As a general rule, put back the gaskets that you took out. The diaphragm is usually sandwiched between 2 gaskets though, so that's likely correct for you.
Hello sir ; first , thank you for the excellent video , couldn’t have done it without you great help , NOW ; could you please have a part number for the two return springs (Excelerator and choke @ 11:04 min.) , I’m going Fing crazy trying to get them , thank you .
Your best bet is a company like Moss Motors. They'll have a parts diagram and can ship the springs to you without needing the factory numbers. Unfortunately I don't know the numbers either, but know that not all chokes had a return spring. If yours didn't have one when you took it apart, it might not need one. You would just need the correct choke cable (the solid rather than stranded one) if you're working on a TR6.
I suppose that's technically possible. As a thought exercise, I see 2 problems. First, you'd need an accurate enough way to measure it. The plunger doesn't move very much, so I imagine a few thousandths one way or another could make a difference. Second, it would be at best a ballpark. In the same way setting the metering needle in a "neutral" position is just a baseline, I'm guessing you'd end up adjusting the bypass valve even after setting it up like you're thinking.
@@midwestmotoring I did a little more searching and I found someone who claimed he set up on bench with vacuum at 20-22 inches. Also Harbor Freight has a Viton o-ring kit that has o-rings that will fit the Stromberg, including the one down around the needle.
I hope you don’t mind me asking for advice, if you do don’t read further, your videos are great. My late 73 Gt6 has a rebuilt engine and has started and ran but not driven. The carbs are cd150se, twin chokes. However, it has developed a problem, it won’t start. The front carb was leaking petrol around the area a where the fuel enters. I thought the flow jet might be blocked but seems clear. After reassembly and hose and pipe replacement things are no better. This time the rear carb is leaking petrol but from the dump canister pipe on the left hand side. These are new old stock carbs but did start up fine and revved ok. Now it fires on two or three cylinders but won’t rev up and after a few moments it dies. Is there any reason why you think there is petrol coming out the emissions pipe? I have a video. Other info: the plungers go up and down freely when the tops are out but it is very difficult to raise them when the tops are in. They raise a little but then it’s very hard to raise by hand. There is petrol also coming out in the main aperture where air goes in. Any suggestions are appreciated. I have a little video I can email you maybe and a pic or two. Kind regards, Ken
So for the leaking fuel a the front of the carbs where the fuel goes in, that's down to a poor seal, way too much pressure, or both. I'd replace the hoses, the hose clamps, and verify the pipe itself is in good shape. If everything is tight, then it won't leak there. Also keep in mind you might be seeing a different leak--for example the float bowl gasket could be leaking. At the rear of the carbs with the emissions control vent... fuel shouldn't be up that high. It's possible you've got too much of a vacuum on the charcoal canister making it through to the carbs. That would be drawing fuel through the vent rather than just venting. I think there should be a restrictor somewhere, or maybe it's in the charcoal canister itself. Unfortunately it's not my area, but that's where my mind is drawn to. Do not block off the fuel vent--it'll just cause excessive pressure and fuel will leak anyway. It shouldn't be difficult to raise the air pistons even with the tops in--at least... it shouldn't be difficult to do it slowly. When everything is assembled, it's intended to slow down how fast the engine can raise the pistons. It'll eventually get to the right height, but not quickly--that makes for a richer mixture when you're accelerating. If the pistons drop back down easily, then it's probably okay. Maybe try a thinner oil in the dashpots if it's still too hard to raise. It sounds like you might have excessive pressure. That would cause fuel leaking from the body of the carb, and probably from the vent. It could also make for a fuel leak where the fuel goes into the carb. I'd get a gauge and plug it in. You should only have 1-2 PSI. Too much more than that and there's your problem. If you have an electric fuel pump, I'd recommend a fuel pressure regulator. I hope that helps!
@@midwestmotoring thanks very much for replying so promptly. I have replaced all hoses and new pipes. My car does not have an emissions canister from new but I bought the carbs but did not recognize the emissions pipe in the side, this was not on the original carbs. I will check the fuel pressure too although it’s a new standard fuel pump. I will keep you posted. Is there any of sending a very short video. Thanks again
Hi there. A question: from 14:28, your right thumb is by a small sprung (I believe) value or piston. It is part of the body of the carb. What is that? Should it move when the throttle is opened just a little bit (either as you demonstrate the 'chock'/ starter box doing, or when you touch the throttle with your foot)? Mine are seized solid on two carburettors, which does 'feel' right. There is an intermediate adjustment screw, suggesting something happens. How would you service that part? Great vid., by the way. Exactly what I need for my Saab 99. Thanks.
I think what you're referring to is a valve built into the carb body. It's part of the float bowl vent, and directs the vent towards either the air cleaner or to the charcoal canister on emissions controlled cars. I address it in the "Rebuilding Zenith-Stromberg CD-175 Carburetors - Disassembly" video at about 25:30. It is supposed to move, but it's not uncommon for it to be stuck. You would ideally free the valve, but earlier carbs didn't have it so it's possible to live without it. If it's frozen where the valve opens towards the exterior vent (to the charcoal canister), you could be venting fuel fumes to the atmosphere--but you should NOT cover the vent. The modification that's not uncommon to do is to open the vent permanently to the inside (towards the air cleaner) so that excess pressure in the float chamber vents into the air cleaner and gets recycled into the carburetor.
My starter box does not have a spring, just a brass pin with a ball bearing ( spring loaded ) that fits into the indent on the cam of the box. Is the spring absolutely necessary ? Hope this reaches somebody.
To whom it concerns, thank so much for your response. Next question : what is the function of the bearing and indent ? When i took the carb. out the bearing was not riding the cam ( nor is it on the other carb. ) and I’m sure had not been for quite some time. I tapped it back into place to allow contact but not sure it’s necessary? Thanks again
Just disassembled the CD175 on a 1973 TR6, the Bypass Valve gasket has been added too, so it blocks off both ports and will not function. Any reason this would have been done? I can provide pictures if it would help. I have no history on the car, but attempting to rebuild the carbs so they work as intended in 1973. Thanks, Robert in OR
Hi Robert, good question. As with many things, the number one reason to block something off is usually due to a lack of understanding of what it does and how to make it work. It's possible the bypass valve was leaking (an easy fix if it was). Or perhaps someone noticed that earlier carbs didn't have the part and disabled it thinking that it detracts from performance (it doesn't). Very commonly with the bypass valves, the diaphragm dries out and stops working--but a new one isn't included in most rebuild kits. It's possible a previous owner saw the gasket was missing and made a new one to block off the unit rather than wait for the correct part. In any case, you're doing the correct thing by putting it back to stock. I'm not suggesting modifying cars is bad, but it's a whole lot better when everything works as a system!
@@midwestmotoring Correct, the rebuild kit from TRF does not contain the diaphragm nor the small o-ring for the adjustable needle. Just a small piece of additional gasket material added on top of the original gasket to cover the ports. Nice video's by the way. Thanks, Robert in OR
Glad I can help. For the life of me, I don't know why they don't include the bypass valve stuff in the rebuild kits. They're ALWAYS dried out and cracked.
I have a 76 Tr6 with 175's. The bypass valves have ports that tie directly from the valves to the distributor. Is this correct? Or should they tie to manifold vacuum as well?
Hi Shane. I could be wrong but I think those are meant to go to manifold vacuum and not the distributor. Maybe someone else will chime in? I believe the distributor should be connected to a fitting on the bottom of one of the carbs, possibly through a thermostatic switch near the radiator.
A good reference is the moss Motors website. They have pictures of the various configurations under emissions control under the intake tab. Sounds like you may have parts from a 74 TR6? I believe early bypass valves got their manifold signal from a tube on the top of the bypass valves like what you're describing instead of a hole machined in... so your bypass valves may not be original to the car. The system also could vary country by country, or by state if you're in the US. You also might be missing some parts. Sorry that's not super helpful... :(
@@midwestmotoring Thank you for replying, I have been able to get my dads car running after 7 years of sitting because of your videos. I am currently fighting a high idle, I've rebuilt both carbs and bypass valves. In doing that I noticed whoever did it before me closed off the trim screws and adjusted the metering needles to max fuel (all the way up) so I put everything back to how it was. It still acts like it needs more fuel so im assuming i have a vacuum leak.
Most often when I find the needles tuned as rich as they'll go, it's either a vacuum leak or the floats not set correctly. Poor ignition timing can also cause similar problems.
@@shaneroot9159 Shane, in my '71 I rebuilt the bypass valve as recommended, and it would just opened wide immediately. Idle was way too fast and pulling way too much air. Maybe it needs a stronger spring. IDK. Whatever, I finally just sealed it off. Put tape over the brass valve. I could not get it to work and the car would idle at 1800-2000 no matter how the fuel was tweaked. It's not a critical feature. More a pollution control valve for deceleration.
I'm just here to look a things I did years ago as a young man and maybe to remind myself of just what might need doing once more before my number is up. I bought a car for my 25th birthday. I'm still driving it today. I turn 71 in about 7 months. Excellent to watch these videos and thanks for the memories. Aug 12 2021. Tom T.
It's pretty amazing to me just how much information is available now that you wouldn't have had 50 years ago. Not to mention how easy it is to have cheap parts delivered to your door. Great job keeping it driving! Age is just a number... so long as you can ignore poor eyesight, and a few other quirks.... anyway 70 is young now according to the irs. You have to be 72 before they start making you withdraw retirement funds nowadays. ;) Stay young, and keep that car on the road!
@@midwestmotoringIts the parts I worry about. Once you'd walk into an auto shop and talk with a man about just about anything. Now you walk into a boutique with funky bopping music going and some 'bun boi' serving you and not having a single clue as to what you want and the usual words coming out of their mouths...... "Nah, Can't help ya". I was just setting up some light rubber sheet to be stored in the car as emergency carby diaphragm material. I go out doing a lot of timber cutting in isolated areas and need to be ready for any emergency. That's what brought me here to your videos. Excellent they are too.
I hear you. I'm hanging on to being in my 30s for dear life and I'm already frustrated with people my own age. My favorite question to get is "what kind of car is that for?" They went out of business about the same time AutoZone was founded. You haven't had it in stock in decades. Stop asking that and just let me look at the rolls of heater hose you keep in the back already!
@@midwestmotoring I specifically refuse to go to the parts shop (headbanging music boutique cosmetic gear for sale), in my home town but will drive for an hour to look around at other places. And yep... Every single time no matter where I go comes the usual, "What's it for" with the person whose asking not having a single clue as to what even a 'set of points' means, let alone an oil seal and a 'collapsible spacer for a Salisbury Diff. I need to find a good online parts dealer. LandRovers. Any ideas.
Sadly not. I've heard Atlantic British is decent with tech support on old Land Rover, but haven't had any experience myself. Could be worth checking out.
This is great info for me. Just bought my first 1974 TR6 to totally restore but l wanted to try and start it to see if it runs. Now l will feel a lot better about rebuilding the carburetors! Thanks!
Dave in AZ
Good luck! Restoring a TR6 is just a lot of little jobs put together. They're great cars!
The TR6 is a great car to restore. The separate chassis means you can get a really good look at every square inch and separate the jobs to be done. Just take your time with the restoration and don't get discouraged. Good luck!
Excellent explanations! Many Thanks! I disassembled the temp compensator because it was stuck. After 50 years, both the plastic pin was rough and the socket slightly oxidized. I stretched a small rag into the cordless screwdriver and polished the bushing bright with aluminum polish. I did the same with the pen. Now nothing is stuck.
Glad it helped!
I have another section of questions about my choke - I am "lucky" enough to have a Series II XJ6C that has the water choke system. I have taken it apart and am cleaning it up, but there is a screw hole on both carbs that looks like an adjustment screw but is missing the screw. should there be a screw here? In general, are these chokes any good and, if not, should I just convert it over to an old style choke and bypass the coolant lines? According to my father in law, these chokes have never worked well at all. Thanks again!
Yeah, I'm not a super big fan of the water chokes, though if I'm being honest it's partly because I don't have them in my cars so I'm just less used to them. Triumph had a sort of auto choke they used on the TR7 which was more or less a separate carburetor bolted where the choke goes. It works fairly well, but I'm not sure it'd fit on your Jag or if the one on the XJ6 is that same system. In truth, if there's a kit for a manual choke it wouldn't hurt to put that on as it'd be more reliable and remove a potential leak spot (that is, unless you're going for originality).
Got it - seems to me to be very complicated and not really doing much to make things better. The Jag Chilton's guide has some info on setting/adjusting it, but I think they have the parts diagramed wrong as you can't actually do what they say to do. Going to just do the rebuild as is and see what we get, but at some point may pull the motor to clean up the engine bay and could do a manual choke kit then (if I can find one). Thanks again!!
Most parts on these carbs can be made operational by simply cleaning them. I don't find they much needs to be adjusted except for the float height and the needle/jet.
On the bypass valve, didn’t you say in the previous video that it had a vacuum leak where that external screw was? How did you fix that? Did the new diaphragm fix it?
In that case I fixed it using a different bypass valve I had laying around. Generally though, cleaning the surface, replacing the o ring, and using a sealant are what I would do.
@@midwestmotoring thank you for responding. I thought about using a sealant actually. I’m not sure if the O-ring is in my rebuild kit or not. I guess its in the bypass valve rebuild kit, which is separate. I do have a large assortment of new O-rings though, and I bet one would probably fit.
Most likely. I've found the orings themselves just do a poor job sealing. I set up bypass valves for a given amount of vacuum, so once set I usually just seal the end before reassembly to prevent it leaking.
My bypass valve has the external vacuum tube as well as the screw adjuster. I’ve mistakenly taken the entire valve part and cleaned it. I set it to where the other carb bypass is set and it does work when a vacuum is applied.
The question is, is there an adjustment once the car is running?
Yes, but realistically if you can get the idle set under 1000 then it doesn't need adjustment
Hello!! Thank you for these videos - without them I would be lost!! Question on the bypass valve - the kit for this has 5 gaskets and when I took mine apart per your instructions, there was a gasket, the diaphram, and then another gasket. In this video you take it apart and there is just the diaphragm and then you put it together with just the diagram. Which way is correct? If as you did it, how come there are so many duplicate gaskets? Thanks in advance!!
Great question! It's a kit meant to suit different variants, so there's a bunch of gaskets and o rings you may or may not need. As a general rule, put back the gaskets that you took out. The diaphragm is usually sandwiched between 2 gaskets though, so that's likely correct for you.
thank you! @@midwestmotoring
Hello sir ; first , thank you for the excellent video , couldn’t have done it without you great help , NOW ; could you please have a part number for the two return springs (Excelerator and choke @ 11:04 min.) , I’m going Fing crazy trying to get them , thank you .
Your best bet is a company like Moss Motors. They'll have a parts diagram and can ship the springs to you without needing the factory numbers. Unfortunately I don't know the numbers either, but know that not all chokes had a return spring. If yours didn't have one when you took it apart, it might not need one. You would just need the correct choke cable (the solid rather than stranded one) if you're working on a TR6.
Well it helps more to know it's function. Thanks
Happy to help. The carburetors on these cars are actually an elegant design. They're just often misunderstood.
Can the bypass be adjusted properly with the vacuum gauge? In other words how many inches of vacuum for a given opening? Great set of videos BTW.
I suppose that's technically possible. As a thought exercise, I see 2 problems. First, you'd need an accurate enough way to measure it. The plunger doesn't move very much, so I imagine a few thousandths one way or another could make a difference. Second, it would be at best a ballpark. In the same way setting the metering needle in a "neutral" position is just a baseline, I'm guessing you'd end up adjusting the bypass valve even after setting it up like you're thinking.
@@midwestmotoring I did a little more searching and I found someone who claimed he set up on bench with vacuum at 20-22 inches. Also Harbor Freight has a Viton o-ring kit that has o-rings that will fit the Stromberg, including the one down around the needle.
I hope you don’t mind me asking for advice, if you do don’t read further, your videos are great.
My late 73 Gt6 has a rebuilt engine and has started and ran but not driven. The carbs are cd150se, twin chokes. However, it has developed a problem, it won’t start. The front carb was leaking petrol around the area a where the fuel enters. I thought the flow jet might be blocked but seems clear. After reassembly and hose and pipe replacement things are no better. This time the rear carb is leaking petrol but from the dump canister pipe on the left hand side. These are new old stock carbs but did start up fine and revved ok. Now it fires on two or three cylinders but won’t rev up and after a few moments it dies.
Is there any reason why you think there is petrol coming out the emissions pipe? I have a video. Other info: the plungers go up and down freely when the tops are out but it is very difficult to raise them when the tops are in. They raise a little but then it’s very hard to raise by hand. There is petrol also coming out in the main aperture where air goes in.
Any suggestions are appreciated. I have a little video I can email you maybe and a pic or two. Kind regards, Ken
So for the leaking fuel a the front of the carbs where the fuel goes in, that's down to a poor seal, way too much pressure, or both. I'd replace the hoses, the hose clamps, and verify the pipe itself is in good shape. If everything is tight, then it won't leak there. Also keep in mind you might be seeing a different leak--for example the float bowl gasket could be leaking.
At the rear of the carbs with the emissions control vent... fuel shouldn't be up that high. It's possible you've got too much of a vacuum on the charcoal canister making it through to the carbs. That would be drawing fuel through the vent rather than just venting. I think there should be a restrictor somewhere, or maybe it's in the charcoal canister itself. Unfortunately it's not my area, but that's where my mind is drawn to. Do not block off the fuel vent--it'll just cause excessive pressure and fuel will leak anyway.
It shouldn't be difficult to raise the air pistons even with the tops in--at least... it shouldn't be difficult to do it slowly. When everything is assembled, it's intended to slow down how fast the engine can raise the pistons. It'll eventually get to the right height, but not quickly--that makes for a richer mixture when you're accelerating. If the pistons drop back down easily, then it's probably okay. Maybe try a thinner oil in the dashpots if it's still too hard to raise.
It sounds like you might have excessive pressure. That would cause fuel leaking from the body of the carb, and probably from the vent. It could also make for a fuel leak where the fuel goes into the carb. I'd get a gauge and plug it in. You should only have 1-2 PSI. Too much more than that and there's your problem. If you have an electric fuel pump, I'd recommend a fuel pressure regulator.
I hope that helps!
@@midwestmotoring thanks very much for replying so promptly. I have replaced all hoses and new pipes. My car does not have an emissions canister from new but I bought the carbs but did not recognize the emissions pipe in the side, this was not on the original carbs. I will check the fuel pressure too although it’s a new standard fuel pump. I will keep you posted. Is there any of sending a very short video. Thanks again
It's not a problem if you haven't got a canister. Just let the carbs vent to atmosphere. Do not block the vents or they'll leak for sure.
@@midwestmotoring great, that’s the way I have it set up.
Hi there. A question: from 14:28, your right thumb is by a small sprung (I believe) value or piston. It is part of the body of the carb. What is that? Should it move when the throttle is opened just a little bit (either as you demonstrate the 'chock'/ starter box doing, or when you touch the throttle with your foot)? Mine are seized solid on two carburettors, which does 'feel' right. There is an intermediate adjustment screw, suggesting something happens. How would you service that part? Great vid., by the way. Exactly what I need for my Saab 99. Thanks.
I think what you're referring to is a valve built into the carb body. It's part of the float bowl vent, and directs the vent towards either the air cleaner or to the charcoal canister on emissions controlled cars. I address it in the "Rebuilding Zenith-Stromberg CD-175 Carburetors - Disassembly" video at about 25:30. It is supposed to move, but it's not uncommon for it to be stuck. You would ideally free the valve, but earlier carbs didn't have it so it's possible to live without it. If it's frozen where the valve opens towards the exterior vent (to the charcoal canister), you could be venting fuel fumes to the atmosphere--but you should NOT cover the vent. The modification that's not uncommon to do is to open the vent permanently to the inside (towards the air cleaner) so that excess pressure in the float chamber vents into the air cleaner and gets recycled into the carburetor.
My starter box does not have a spring, just a brass pin with a ball bearing ( spring loaded ) that fits into the indent on the cam of the box. Is the spring absolutely necessary ? Hope this reaches somebody.
Hello! Nope, spring is not necessary. Cars with a solid (not stranded) choke cable didn't have springs.
To whom it concerns, thank so much for your response.
Next question : what is the function of the bearing and indent ? When i took the carb. out the bearing was not riding the cam ( nor is it on the other carb. ) and I’m sure had not been for quite some time. I tapped it back into place to allow contact but not sure it’s necessary? Thanks again
Just disassembled the CD175 on a 1973 TR6, the Bypass Valve gasket has been added too, so it blocks off both ports and will not function. Any reason this would have been done? I can provide pictures if it would help. I have no history on the car, but attempting to rebuild the carbs so they work as intended in 1973. Thanks, Robert in OR
Hi Robert, good question. As with many things, the number one reason to block something off is usually due to a lack of understanding of what it does and how to make it work. It's possible the bypass valve was leaking (an easy fix if it was). Or perhaps someone noticed that earlier carbs didn't have the part and disabled it thinking that it detracts from performance (it doesn't). Very commonly with the bypass valves, the diaphragm dries out and stops working--but a new one isn't included in most rebuild kits. It's possible a previous owner saw the gasket was missing and made a new one to block off the unit rather than wait for the correct part. In any case, you're doing the correct thing by putting it back to stock. I'm not suggesting modifying cars is bad, but it's a whole lot better when everything works as a system!
@@midwestmotoring Correct, the rebuild kit from TRF does not contain the diaphragm nor the small o-ring for the adjustable needle. Just a small piece of additional gasket material added on top of the original gasket to cover the ports. Nice video's by the way. Thanks, Robert in OR
Glad I can help. For the life of me, I don't know why they don't include the bypass valve stuff in the rebuild kits. They're ALWAYS dried out and cracked.
I have a 76 Tr6 with 175's. The bypass valves have ports that tie directly from the valves to the distributor. Is this correct? Or should they tie to manifold vacuum as well?
Hi Shane. I could be wrong but I think those are meant to go to manifold vacuum and not the distributor. Maybe someone else will chime in? I believe the distributor should be connected to a fitting on the bottom of one of the carbs, possibly through a thermostatic switch near the radiator.
A good reference is the moss Motors website. They have pictures of the various configurations under emissions control under the intake tab. Sounds like you may have parts from a 74 TR6? I believe early bypass valves got their manifold signal from a tube on the top of the bypass valves like what you're describing instead of a hole machined in... so your bypass valves may not be original to the car. The system also could vary country by country, or by state if you're in the US. You also might be missing some parts. Sorry that's not super helpful... :(
@@midwestmotoring Thank you for replying, I have been able to get my dads car running after 7 years of sitting because of your videos. I am currently fighting a high idle, I've rebuilt both carbs and bypass valves. In doing that I noticed whoever did it before me closed off the trim screws and adjusted the metering needles to max fuel (all the way up) so I put everything back to how it was. It still acts like it needs more fuel so im assuming i have a vacuum leak.
Most often when I find the needles tuned as rich as they'll go, it's either a vacuum leak or the floats not set correctly. Poor ignition timing can also cause similar problems.
@@shaneroot9159 Shane, in my '71 I rebuilt the bypass valve as recommended, and it would just opened wide immediately. Idle was way too fast and pulling way too much air. Maybe it needs a stronger spring. IDK. Whatever, I finally just sealed it off. Put tape over the brass valve. I could not get it to work and the car would idle at 1800-2000 no matter how the fuel was tweaked. It's not a critical feature. More a pollution control valve for deceleration.
I have a different choke disc in my stromberg. The holes are located mirrored. It can't work in mine
Hmm... I'm not familiar with that design then. Can you send a photo?
@@midwestmotoring where can I send it? I have pictures
@@robvanspijk midwmotoring@gmail.com