I am in no way an expert on carburetors – it’s been more then 20 years since I’ve dealt with them – but I don’t recall putting oil I n any of them, seems that will result in a lot of smoke and stalling. I was not aware carburetors had pistons, either.
Please post a diagram of the carburetor showing the piston and a passage from the service manual indicating carburetor oiling.
In the mean time I still think your carbs are shot and need to be replaced or rebuilt.
10 is the piston, 57 the damper. On the pictuere is the 175 CD (Constant depression) for M115, which should be filled with motor oil in summer and ATF in winter. The 175 CDT (which Haroundb has in his car) needs ATF all year.
It looks the same as the Stromberg in the 240 series Volvos. I always kept ATF in mine (moderate climate) all year around. It's no panic, it just dampens the movement of the needle. If the diaphram rips, however, you will know right away(unlike another kind of diaphram where you find out 9 months later).
Thanks for the info, looks straight forward to me, Haroundb, tell your mechanic to do what he needs to do or you do it yourself. Let us know if the problem goes away. If not you may still need to replace the carbs.
its the same carb used on early English cars as well in the summer or hot places a 10 30 motor oil and in the cold AFT -- BUT its really a driving thing you can use an eye dropper and to suck oil out if car is flat and wont rev up, the oil is too thick needs to be thinner a pop or a hesitation, you might want a little thicker oil i hope you get what i mean -- please note if the car is not driven much the rubber boot under the top can leak causing all kinds of running and idle problems -- real easy to change and the mix has a screw that you can adjust the mixture on the side geta book its a real easy - dumb carb nothing that cant be adjusted out of it -- pares or trips you will need a ( forgot the name )( unison i think ) i am sure that is not how to spell it - its used to balance them -- more than one buy the volume of air entering the carb -- have a book i think that shows the carb on a Benz send me the year and # of car i will look -- jz
sorry i did not read the post till after and i was not thinking newer benz i have the book and took pictures i hope they came out -- sorry if i stepped on your answer -- jz
Thanks very very very much for the great input people, I really appreciate it and now I feel right between my brothers. I will do what is right to be done, I know more enlightened about my carb, thanks to everyone especially johnjzjz for his effort.
I am in no way an expert on carburetors – it’s been more then 20 years since I’ve dealt with them – but I don’t recall putting oil I n any of them, seems that will result in a lot of smoke and stalling. I was not aware carburetors had pistons, either.
I have access to a lot of data about your carb, which is a Stromberg 175 CDT. Most of it in german. If you tell me, what your promblem is, it is not unlikely, that I can help you.
I'd never heard of using oil in a carb till I had a 1967 Datsun 1600. Turned out you could "tune" the resonsiveness of the carb by changing the viscosity of the oil that was in it. The extremes were Marvel Mystery Oil to 10W30. I don't think anything like this was ever used on American cars, so it's definitely a "foreign" concept.
Again. There is no "rule" about what oil to use. Off course there are specifications, but it is not problem trying to use some different viscosities. The oil is not there for greasing or cooling purposes (like engine or transmission oil), but only for damping the piston. And since the viscositiy of the oil is linked to temprature, different oil is used in different climates.
Not to mention personal preferences, or wear during use. My mini (British car) is using the same system, and I use regular enige oil (15W40). But in cold winters I sometimes change it tot "house hold oil".. Nothing special. Just a lot less thick..
I have access to a lot of data about your carb, which is a Stromberg 175 CDT. Most of it in german. If you tell me, what your promblem is, it is not unlikely, that I can help you.
I want the way to calibrate the carb to the correct level. I had lots of ups and downs by many mechanics. Everyone had his own ideas, so I need to know how to reset it to the correct value.
Also need to know if it correct to put additives into the gas tank so to clean the carb. I don't know if this worths money paid or just simply a waste of time and money. I care for my car, I respect people who do so, many said that I just have to drive till a real problem happens but this is totally not me.
Thanks for the big help martin and sure I will ask your kind help because you are a kind man.
Thanks everyone for the great replies and please keep the wonderful input.
The dashpot on these carbs modulates the response of the needle valve to throttle input. If the oil is too viscous the throttle response will suffer.
What usually happens is the piston of the dashpot wears and the oil runs out. Then the owner puts in a heavy oil to try to stop the leaking, and finds his throttle response is terrible.
The solution in that case is to rebuild the carb. You can buy rebuild kits that are fairly easy to install, takes about an hour.
My extensive experience with the SU semi-side-draft carbs on MGs, which used the dashpot technology, caused me to refer to these engines as having "Same-Day Throttle Response".
I want the way to calibrate the carb to the correct level. I had lots of ups and downs by many mechanics. Everyone had his own ideas, so I need to know how to reset it to the correct value.
Also need to know if it correct to put additives into the gas tank so to clean the carb. I don't know if this worths money paid or just simply a waste of time and money. I care for my car, I respect people who do so, many said that I just have to drive till a real problem happens but this is totally not me.
Thanks for the big help martin and sure I will ask your kind help because you are a kind man.
Thanks everyone for the great replies and please keep the wonderful input.
You're welcome! The calibration of the carb has to be done with a warm engine with a Co-analyzer.
Here's the basic data:
RPM (warm): 850±50
CO (warm): 1.5 ± 0.5 Vol. %
RPM (cold): 1700±100
CO (cold): 7±1 Vol.%
I would not recommend to use any cleaning additives, first you don't really know the effects, and then the carb is a really simple thing - you can open it easy, clean the dirty parts, replace what needs to be replaced (like diaphragm and needle), and re assable it.
QUOTE :: I want the way to calibrate the carb to the correct level --- best thing to do is not that i cant telll you but the english car guys, will have pictures and methods, that can be used buy you at no cost, and show in picture form -- that is the best way to get to what you want to do -- jz
You're welcome! The calibration of the carb has to be done with a warm engine with a Co-analyzer.
Here's the basic data:
RPM (warm): 850±50
CO (warm): 1.5 ± 0.5 Vol. %
RPM (cold): 1700±100
CO (cold): 7±1 Vol.%
I would not recommend to use any cleaning additives, first you don't really know the effects, and then the carb is a really simple thing - you can open it easy, clean the dirty parts, replace what needs to be replaced (like diaphragm and needle), and re assable it.
QUOTE :: I want the way to calibrate the carb to the correct level --- best thing to do is not that i cant telll you but the english car guys, will have pictures and methods, that can be used buy you at no cost, and show in picture form -- that is the best way to get to what you want to do -- jz
You're welcome! The calibration of the carb has to be done with a warm engine with a Co-analyzer.
Here's the basic data:
RPM (warm): 850±50
CO (warm): 1.5 ± 0.5 Vol. %
RPM (cold): 1700±100
CO (cold): 7±1 Vol.%
I would not recommend to use any cleaning additives, first you don't really know the effects, and then the carb is a really simple thing - you can open it easy, clean the dirty parts, replace what needs to be replaced (like diaphragm and needle), and re assable it.
I was just wondering how come when it is cold it gets a higher RPM and when warm a lower one? Also I don't have an RPM in my Benz, how can I go around this?
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