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MG MGA - Refitting carburettors

Hi
Just a very simple question please. I have just removed my carbs for refurbishment, but found it incredibly difficult to remove the two nuts underneath, holding carb assembly to engine. Especially the rear one. What bothers me is doing them up is likely to be very much worse!
Is there a trick or special tool I should know about? Many thanks
Graham M V

Graham. Open end spanner and the ability to lay on the fender on your stomach while reaching under the heat shield with your arm. Easier for someone with smaller arms and hands to do than for male adults. Patience is your friend here as it takes a long time to do the nuts up tightly.

Les
Les Bengtson

Graham, I use an open ended spanner with a slight bend and have no real difficulty. And my hands are large. Experiment with the degree of bend - I put it in a vise and gave it a tap with a hammer - just bend near the head of the shank.
Good luck, Barry
BM Gannon

Graham,I agree with Barry.Buy cheap spanners at the local auto store (eg Super Cheap here in Aus at $1 each) and bend or cut and weld them every which way.It makes the job easy. Jim.
jim mckenzie

Graham, to make it easier, clean up the stud and nuts with a re-threading tool or taps and dies so that the nuts goes on easily. This way you can use your fingers for most of the turning and only have a few turns remaining with the spanner. I found that the short stubby open ended spanner work best. I always tighten the top one first that makes the bottom ones easier. Make sure that both carb shafts are in line or it might bind later.

Andy
Andy Preston

OK thanks. So I guess lots of grazed knuckles and bad language is the only way!

Can I also check the correct anchor point for the throtle return spring please. Mine was simply hooked round the bottom of the heat shield which I doubt is correct.
Should it be to the small anchor bracket welded on the angled chassis member. I am not sure as this looks a bit like a PO modification and it was previously anchoring a spring to the choke lever assembley (but I have already been told the "choke spring" simply should not have been there. Presumably it was a (failed) attempt to correct the problem with the choke not disengaging properly).
I have looked on various carb diagrams but cannot see the spring anchorage clearly anywhere.
The "top" end of the throttle spring was on the clamp attached to the throttle cable which looks correct.
Many thanks for all the help
Graham M V

OK thanks. So I guess lots of grazed knuckles and bad language is the only way!

Can I also check the correct anchor point for the throtle return spring please. Mine was simply hooked round the bottom of the heat shield which I doubt is correct.
Should it be to the small anchor bracket welded on the angled chassis member. I am not sure as this looks a bit like a PO modification and it was previously anchoring a spring to the choke lever assembley (but I have already been told the "choke spring" simply should not have been there. Presumably it was a (failed) attempt to correct the problem with the choke not disengaging properly).
I have looked on various carb diagrams but cannot see the spring anchorage clearly anywhere.
The "top" end of the throttle spring was on the clamp attached to the throttle cable which looks correct.
Graham M V

Graham

...and I thought it was just me that found it difficult to access those bolts. Fitting that flame trap in position can also be fun.

Yes, the spring should attach through the hole in the bottom of the bracket, also fiddlesome. Image attached. Don't ask me how I got the camera there, perhaps I should weld the spanner to it!

Steve

Steve Gyles

Attached is a picture of a set of Jim McK. 1/2" and 9/16" bent spanners ($4) for working on the carbies and such, plus the more expensive (less efficient) Alden racheting open ended spanner (~$25).
Mike

Mike Ellsmore

I have a feeling Graham is missing the spring brackets, no doubt because the last guy couldn't figure out how to get those nuts off either! We used to see a lot of cars with springs going to that frame bracket.
I've got a good collection of 2" long wrenches, originally for carbs, but they are incredibly useful in all sorts of places, like behind the instrument panel. I even brazed a loop on the 9/16" one and used to have it on a rawhide lanyard to my belt, along with the SU jet adjusting wrench.

FRM
FR Millmore

Thanks. Steve the photo is exceptionaly helpful as I didn't know there should be that black anchor bracket on the bottom of my carburettor! Its not even shown on the exploded diagrams of the carburettor but I now see it on the "engine controls" diagram. My bracket is obviously home-made as it is welded lower down on to the chassis member. So thanks also to FRM as you guessed right (I assume just a typo as FRM refers to brackets - i.e. in plural, but assume only one bracket).
Well I need to get one of those and am sure it will make it even more difficult to get to that bolt underneath! - but maybe solved with Mike's spanners!

I would be lost without your help so really grateful for input.
Graham M V

Graham

FRM is correct with the plural. The first bracket is the one fitted to the carburettor mounting stud (item 40 in the attached image), anchoring the bottom of the spring. The other is the spring upper mounting bracket (item 29 in the attached image). This tab locates on the accelerator clamping spindle.

Steve

Steve Gyles

Graham and others,
I have removed my carbs two are three times by removing the entire assembly.....intake manifold, heat shield, both carbs, etc come as one unit.
The heat shield makes it more difficult to access the intake manifold nuts, but can be done.
No messing with the linkage on re-assembly....and saves on replacing gaskets.
To get the nuts started again one handed. I put a little grease on my finger tip to hold the nut to my finger. I agree, keep the threads clean helps a great deal.
Ray Ammeter

I almost do the same as you Ray, but take the heat shield out separately.

As an aside I threaded the throttle outer cable anchor to set it at an appropriate angle to avoid the cable touching the rocker cover.

Steve

Steve Gyles

Thanks Steve. I do at least have item 29!
I took my carbs off with the linkages all in place. Is it easier to put them back after fitting carbs?
Graham M V

Graham

Like Ray, I tend to keep them both linked together. Saves having to refer to the manual to see how to connect them all up again - memory fades as you grow old. Once fitted, you will need to slacken the central throttle spindle when you balance the carbs, but that is about it.

Over the years I have cheated a bit when setting the mixture (number of flats on the jet nut) by measuring the depth of each jet below the bridge before taking the carbs apart. I then set the jets (with new glands etc) to the same depth. Seems to work quite accurately and saves a lot of messing around.

Steve
(written late at night after a bottle of wine - hic. I will defend myself in the morning!)
Steve Gyles

Many thanks all cheats gratefully received! Will probably send them off to be professionally refurbished as worried I wont be able to drill through the spindle accurately with only a hand drill. Main downside is the turnaround is 6 to 8 weeks and not so much satisfaction.
Thanks for all the help
Graham M V

Graham

Some suppliers do exchange services. My carbs were well past their sell-by date after 22 years in a barn. Bob West did a straight swap for me, plus a bit of money from me to him. Might cut your turnround time to a week instead of 2 months.

Steve
Steve Gyles

I phoned around all the suppliers and nobody had a unit they could offer on exchange. But I spoke with Bob West and he offered as 3 week turnaround which is very much better, so thanks for that Steve.
A little more expensive than the company I was going to use but not that much in it. I am happy knowing they are going to someone who I have only heard good reports of and that they are coming back quicker!
Graham V

Graham, I found that cutting an open ended spanner in half made taking the carb nuts off a whole lot easier. You still need to feel the spanner onto the nut but this is easier due to the shorter length. Undo the bottom nut first and do it up last when tightening it back down.
It works for me!!

Neil
Neil Purves

Thanks for the tip Neil - seems like a good idea
Graham V

This thread was discussed between 05/02/2010 and 09/02/2010

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This thread is from the archive. The Live MG MGA BBS is active now.