H1 Carburettor seal replacement

for those with Series MM sidevalve cars produced between September 1948 and February 1953
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gtt1951
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H1 Carburettor seal replacement

Post by gtt1951 »

I've finally got around to taking the leaking carb off my MM side-valve to give it a clean and fit the gasket/seal set I bought from Sparesman.
No wonder it was leaking! No sign of the two small cork seals that surround the jet assembly, no gasket between the suction chamber and carb body, broken cork gland that is held in by the Jet sealing nut and, quite surprisingly, no piston spring!

Before I took it off, the engine was running very sweetly, but the carb was leaking lots of fuel after switching off.
Was the H1 carb one of those that didn't need the long spring?
The Burlen Fuels website for SU carbs shows the H1 main components (and their alternatives), but does not have the spring in its parts list (it is on the exploded diagram as item No. 2).
http://sucarb.co.uk/carbspec/carburetto ... s/id/1896/
If the H1 carb does need a spring, then I have a spare SU HS2 carb that I'm "refurbishing", whose spring I could borrow (if it is the same), or I can pop into Moss Europe (down the road from work) to get one of theirs (for a HS2 carb) at just under £7.00 - but are the springs the same?

Any help gratefully received,

George.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
mike.perry
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Re: H1 Carburettor seal replacement

Post by mike.perry »

There is no piston spring on the Series MM H1, although I do not know what difference it would make fitting one. It is one of the things I want to try out, along with vacuum advance when I set my car up on the rolling road. I need a few more miles running in first.
Carb seal kits are available from Burlen Fuels. I found it easier to strip down and lay out a spare carb so that I could follow the order of the parts when re assembling the rebuilt carb
Last edited by mike.perry on Sat Aug 31, 2013 7:28 pm, edited 1 time in total.
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gtt1951
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Re: H1 Carburettor seal replacement

Post by gtt1951 »

Mike, thanks very much for your answer. I'll put it back without a spring. I only have the 1 MM H1 carb, although the carb on my spare 803 engine looks to be a H1, but of a slightly different external appearance.
I'll have to take the jet out again, as I only realised what the 2 small cork seals were for after I had put that section back together. Should have looked at the book first!
I've got the 2 small seals soaking in some SAE30 oil, at the moment, back home.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
mike.perry
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Re: H1 Carburettor seal replacement

Post by mike.perry »

The 803 H1 is the same as the MM carb as far as the jet design is concerned. The cork seals should be soaked in oil for 24 hrs
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sparesman
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Re: H1 Carburettor seal replacement

Post by sparesman »

Mike
We have lots of original MM/S11 carb seal kits in the club stocks , part number AUE18, so there is no need to tell owners to go to Burlen.Also have some AUE19 kits which are for the early 948 where the only difference is the float chamber diameter.
1934 Morris 10/4 in Dark Green / Black - BGO517
1953 S11 Traveller in Birch Grey - oldest survivor ? Export model now reg PPO924
1953 S11 Traveller in Black - 3rd oldest in UK PPX344
TvdWerf
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Re: H1 Carburettor seal replacement

Post by TvdWerf »

Is this the same as the rebuild kit from ESM?
My H1 was in a box for years, it could be a idea to service this before using...
MM '51 LHD sidevalve
gtt1951
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Re: H1 Carburettor seal replacement

Post by gtt1951 »

mike.perry wrote:The 803 H1 is the same as the MM carb as far as the jet design is concerned. The cork seals should be soaked in oil for 24 hrs
All 3 cork seals have been soaked and now fitted[frame]Image[/frame]The fuel banjo connector had about 4 seals/washers on it and I couldn't see enough in the seal pack to cover this. Turns out that whoever last did any work on this, got the banjo round the wrong way and had to but in extra washer seals to pack it up. On the left you can see a slightly larger diameter seal covering the correct sized one that had slipped down into the banjo recess. There are 2 seals on the right.[frame]Image[/frame]
Fitted the correct way round the 2 remaining seals were all that was needed. Carb now back together (last night) and ready for fitting this morning[frame]Image[/frame][frame]Image[/frame][frame]Image[/frame]
Let's hope that I don't get any leaks now - have to change the fan belt and, at least, the top rad hose too.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
gtt1951
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Re: H1 Carburettor seal replacement

Post by gtt1951 »

Carburettor back on, but did have a slight leak[frame]Image[/frame]A bit of tightening (with the spanner in the picture) and all became well[frame]Image[/frame]Adjusting the mixture, by ear, wasn't as easy as the HS2 carb on my Traveller - very difficult to hear the changes. Resorted to using my old Gunson's Colortune, and I was only a little bit weak. Sounds OK now, but not road tested as had to see to the frayed fan belt and perished top hose - Oh Dear :(
See new thread on "replacing Series MM Side-valve fan belt.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
gtt1951
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Re: H1 Carburettor seal replacement

Post by gtt1951 »

sparesman wrote:Mike
We have lots of original MM/S11 carb seal kits in the club stocks , part number AUE18, so there is no need to tell owners to go to Burlen.Also have some AUE19 kits which are for the early 948 where the only difference is the float chamber diameter.
Bryan, the seal kit I used was bought from you, but the estimated original 10/6 price tag seems to have morphed into £8 :wink:
I did look at the Burlen's offerings and some of their kits have many more parts/bits that you may not need. I could have done with a kit that had gaskets for both the air silencer and the inlet manifold joint - that is why I didn't take off the air silencer component whilst servicing the carb (the manifold gasket was reused as I took this off very carefully and all the other carb gaskets I have are a lot larger).
Regards
George.
Image
'50 Low-light with 918 Side-valve engine,
'51 High-light with Side-valve 918 engine,
'55 4-dr with 803 engine,
'56 Traveller with 1098 engine.
sparesman
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Re: H1 Carburettor seal replacement

Post by sparesman »

gtt1951 wrote:
sparesman wrote:Mike
We have lots of original MM/S11 carb seal kits in the club stocks , part number AUE18, so there is no need to tell owners to go to Burlen.Also have some AUE19 kits which are for the early 948 where the only difference is the float chamber diameter.
Bryan, the seal kit I used was bought from you, but the estimated original 10/6 price tag seems to have morphed into £8 :wink:
I did look at the Burlen's offerings and some of their kits have many more parts/bits that you may not need. I could have done with a kit that had gaskets for both the air silencer and the inlet manifold joint - that is why I didn't take off the air silencer component whilst servicing the carb (the manifold gasket was reused as I took this off very carefully and all the other carb gaskets I have are a lot larger).
Regards
George.
George
I am sure that we had to pay a lot more than 10/6 to buy the kits.As you know most of the parts we have are original parts whenever I can find them not modern repro items but I do try to ensure the selling price is lower than the repro parts whenever possible.I may have the other gaskets you mentioned but given the POs extortionate prices for posting items thicker than 5mm postage would probably be more than value of the gaskets.
1934 Morris 10/4 in Dark Green / Black - BGO517
1953 S11 Traveller in Birch Grey - oldest survivor ? Export model now reg PPO924
1953 S11 Traveller in Black - 3rd oldest in UK PPX344
beavan
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Re: H1 Carburettor seal replacement

Post by beavan »

Just reading through this as I am going to the similar process of changing the gaskets on my carb. It’s an 803cc. I called Burlen Fuel Systems who advised me that there is no piston spring on some models, the way of determining this is by weighing the piston, if it is 7.3 ounces it does not need a spring.
philthehill
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Re: H1 Carburettor seal replacement

Post by philthehill »

You do not have to weigh the piston to determine if the damper spring is required or not.
There is an obvious steel weight which sits in the upper well of the piston. If the weight is there then the spring is not required.
It should also be noted that some weighted damper pistons do not have the damper oil piston only the screwed cap.

gtt1951
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Re: H1 Carburettor seal replacement

Post by gtt1951 »

Revisiting this dated post, I'm saddened to see that all the photographs have been lost.
Which website move did this? The 1st or the 2nd?
I thought I read somewhere that the images had been saved - not a lot of use, reading articles that rely on embedded images, if all these have gone!
What possessed the MMOC to screw things up so badly????
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geoberni
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Re: H1 Carburettor seal replacement

Post by geoberni »

gtt1951 wrote: Fri Nov 11, 2022 6:55 pm
What possessed the MMOC to screw things up so badly????
As a Member, but nothing to do with MMOC organisation structure nor this message board, I thought I'd reply to your post.

It is apparent that in the past, the MMOC has been badly let down by service providers in hosting this site.
Sometimes these things happen and nothing can be done about it, especially when dealing with IT.
I know simply from reading the threads this past 5 years that there have been problems with different hosting providers.

So simply as a fellow member, I find your initial question fair enough, but your final accusation somewhat abrupt and unnecessary addition.
I'll now leave it to one of the backroom volunteers to give you a more detailed explanation if they so wish.
Basil the 1955 series II

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