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Mr Royston Goodman
United Kingdom
14 Posts |
 Posted - 25/06/2025 : 19:09:37
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I've just dipped my toes into the MMM world and purchased an M Type. Can anyone advise me what model of SU carb this is, and where in the UK can I purchase a service kit, float needle, jet, and carb needle?
Royston Goodman |
Edited by - Mr Royston Goodman on 25/06/2025 19:11:33 |
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coracle
United Kingdom
2305 Posts |
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Mr Royston Goodman
United Kingdom
14 Posts |
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sam christie
United Kingdom
3195 Posts |
Posted - 26/06/2025 : 09:26:36
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You certainly seem to have an original M-type carburettor including the float chamber which is commonly seen replaced with a later equivalent.
Sam |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 26/06/2025 : 09:53:27
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Excellent information Sam, thank you for the confirmation. The issue is the float needle is not seating in the base of the bowl, so fuel flows freely, all the time...not ideal. I can see the needle is worn and they say not to attempt to correct this??? I'm hoping SU/Burlen can come up with a solution.
Royston Goodman |
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Keith Durston
United Kingdom
756 Posts |
Posted - 26/06/2025 : 11:33:24
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Royston, I have had the same issue with my M Type carb and Burlen supplied me with a new style float valve that was in a nylon carrier and included, if I remember rightly, a light weight spring to help it seal. I could not get this to work correctly and I assumed/deduced it was probably because the petrol pressure was purely gravity and not from a pump. I resorted to carefully regrinding the old stlye pointed steel needles mating them with the brass seat until I had a good seal again. I am still using this 12 years later with no problems. If you look at your needle and seat you will probably see signs of a ring where the the seal is made. You need to regrind this with fine grinding paste and finally cutting oil until it has gone and then check the seal with petrol.
Good luck,
Keith |
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sam christie
United Kingdom
3195 Posts |
Posted - 26/06/2025 : 11:41:38
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Thanks Royston, though I have failed to answer the question as to which model of SU carb this is.
The alloy the old flat topped float chambers were made from ages badly and they prove increasingly troublesome. It might be easier to use a later float chamber and I am sure Burlen will advise about this.
Sam |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 26/06/2025 : 12:09:28
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Thank you Keith, sounds positive, so I'll give that a bash in the first instance. Failing that I'll go down the route Sam has suggested. Nothing to lose. krgds Royston
quote:
Originally posted by Keith Durston
Royston, I have had the same issue with my M Type carb and Burlen supplied me with a new style float valve that was in a nylon carrier and included, if I remember rightly, a light weight spring to help it seal. I could not get this to work correctly and I assumed/deduced it was probably because the petrol pressure was purely gravity and not from a pump. I resorted to carefully regrinding the old stlye pointed steel needles mating them with the brass seat until I had a good seal again. I am still using this 12 years later with no problems. If you look at your needle and seat you will probably see signs of a ring where the the seal is made. You need to regrind this with fine grinding paste and finally cutting oil until it has gone and then check the seal with petrol.
Good luck,
Keith
Royston Goodman |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 26/06/2025 : 12:12:17
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Hi Sam, I'll try the method that Keith has suggested. If that doesn't work, then I'll opt for the replacement float chamber. If I find out the model details for Burlen on the original float chamber, I'll post them back here.
krgds Royston
quote:
Originally posted by sam christie
Thanks Royston, though I have failed to answer the question as to which model of SU carb this is.
The alloy the old flat topped float chambers were made from ages badly and they prove increasingly troublesome. It might be easier to use a later float chamber and I am sure Burlen will advise about this.
Sam
Royston Goodman |
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Nick Feakes
USA
3619 Posts |
Posted - 26/06/2025 : 14:42:17
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Royston
Welcome to the forums. Have you had a look at the technical downloads section? Go to triple-mregister.org (or click on Home in blue at the top of the page), then from the menu of the left select Document downloads then Technical You will find a huge amount of information about almost every aspect of our cars, gathered over many years.
Also try using the "Search" function from the top of the page (in blue). That will give you access to the thousands of pages that have been archived over the years.
Nick
Webmaster |
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DK6780
United Kingdom
437 Posts |
Posted - 26/06/2025 : 15:47:23
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| Interesting that you have that carb on such a late car - I'd expect it to be the other type. There's a lot written and said that the earlier float chambers are unreliable but my experience (on other car makes) is that they work well. But on MGs I only have the later type so can't comment directly. If you want to swap to one of the later float chambers I'd be happy to oblige. |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 26/06/2025 : 16:33:48
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Thanks Duncan, I have contacted Burlen, I doubt they will be able to help, so I may come back to you on that. rgds Royston
Royston Goodman |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 26/06/2025 : 16:40:33
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Thanks Nick, extremely helpful, it's a great site. krgds Royston
Royston Goodman |
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LewPalmer
USA
3370 Posts |
Posted - 26/06/2025 : 22:12:11
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On 2M1281, I had the later style float bowl, but through a trade, was able to acquire the flat-top bowl. I have since sold the car, but to the best of my knowledge, the flat-top bowl is still functioning. well. It simply looks the part.
Lew Palmer
PA1169, NA0651 |
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TomDrewett
United Kingdom
308 Posts |
Posted - 28/06/2025 : 16:10:36
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Royston
When I was in the same spot I did get a replacement needle, I’m sure Burlen provided it, but I will check my notes
Tom |
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Mr Royston Goodman
United Kingdom
14 Posts |
Posted - 28/06/2025 : 19:05:48
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Thanks Tom, I've forwared all the details to them, hopefully they will have an answer, I'd rather keep the setup the way it is, good solution from one of the other responders, to finely grind the float pin into it's seat, I'll definately give that a go if Burlen don't have the best solution. krgds Royston
quote:
Originally posted by TomDrewett
Royston
When I was in the same spot I did get a replacement needle, I’m sure Burlen provided it, but I will check my notes
Tom
Royston Goodman |
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Topic |
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M Type Carburettor
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