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New Acquisition: Austin Maxi


cbowditch

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My next door neighbour has a 1750 Automatic Maxi when I was about 5 and I remember sitting in the back watching for the gear lever to move when the car changed gear! :oops:

I expected automatic gear levers to magically move themselves when I was a kid too.

 

Life is so full of disappointments.

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Carbs are easy to balance. You want a bit of washer hose small enough to get in your ear. Put the other end across the mouth of the carb with the engine idling. You'll hear one hissing and the other chugging if they're out of balance. Simply twiddle the balance bar until they both sound the same. Job jobbed.

 

Thanks for the hint. By balance bar, you mean the bar that connects the 2 throttles? How do I set the mixture? I have the idle on lowest setting but it seems to be idling too fast. I suspect I need to weaken the mixture off a bit too. Sorry I'm a bit of noob when it comes to carbs. I was quite pleased that I managed to strip them down clean them up and replace the jets without any help  :-D

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assuming they are good old su's,my method was always thus: turn up idle speed a bit.screw OUT mixture nut (rich) until it starts going lumpy,then screw in until the idle speed rises and it runs evenly and fast,then reduce idle speed.for your twin carb setup,im assuming my method would be to do the same to each carb,then adjust the balance bar so that they both open at the same time,from memory there is a clearance to set between the throttle arm and the carb.

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Thanks for the tips platicvandan. That seems to follow the same lines as the Haynes manual, except in a simplified way. There are like 70 steps in the Haynes  :shock:

 

I think the mechanical advance in the dizzy is foobarred. I timed it statically thinking I just needed to fine tune the timing when it was running and found the timing was over 30 degrees out when running! I stopped the engine and again checked the timing statically and it was still spot on. So I started the engine again, and it was 30 degrees out again. I had definitely disconnected the vacuum dizzy, so this difference must be down to the mechanical advance mechanism. I can't think what else would cause it? But it could explain difficulty starting and poor running. Rather than try to track down a replacement points dizzy I have ordered an electronic one since they are available for under £60 on a certain auction site.

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beware of the electronic dizzys,they have a totally generic advance settings and you may find it worse! the mechanical advance rarely plays up on these,usually the vac does (easy to test,suck on the pipe and see if it moves) Static timing only goes so far,really you need to time it when its running,wear and play in the points etc all play their part.make sure the carb dashpots are topped up with thin oil as well.

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I still haven't been able to drive this, since sorting the timing, the ignition light came on. I initially thought it was the 11 year old battery cos I'd discharged it a few times fixing the carb, etc. Well, should have tested it really as the ignition light stayed on after replacing it  :mad:

 

So I tested the alternator and it was fooked! So I had to order a new one and wait a few days. It finally arrived today. Here's new next to old. Now fitted, but I've run out of time tonight, so I'll save the test drive for tomorrow!

post-5681-0-67718500-1506971806_thumb.jpg

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beware of the electronic dizzys,they have a totally generic advance settings and you may find it worse! the mechanical advance rarely plays up on these,usually the vac does (easy to test,suck on the pipe and see if it moves) Static timing only goes so far,really you need to time it when its running,wear and play in the points etc all play their part.make sure the carb dashpots are topped up with thin oil as well.

 

I disconnected vac pipe when setting the timing, so I wouldn't have thought that was responsible. You're right about static timing isn't that accurate but normally gets you within +/- 3 degrees. I didn't expect to be 30 odd degrees out. It was almost in the next cylinder!

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Latest Update: Finally managed to test drive it. Its still running badly once choke is pushed in. When I stopped and opened the bonnet I noticed a load of smoke coming from the area of the n/s carb. The previous owner has fitted some make shift heat shields made from hard board and this is what appears to be smoking. o/s one seems fine. I checked the tightness of the bolts thinking the carb might not be seated down properly; but they are all done up tight. The smoke continued for several minutes after the engine stopped. I'm not sure what's causing that. I'm going to try taking the heat shields off. There is a small blow from the down pipe, but that wouldn't cause so much smoke from n/s carb several minutes after the engine is stopped.

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These heatshields - can you post a photo? The factory fit items are indeed made of some board-like material so they may be correct.

 

You sure oil or something hasn't spilt onto the xhaust and is now burning off?

 

Interesting. Difficult to get a clear pic with them on the car. Some petrol was spilt on the other heat shield when the jet leaked, but that one isn't smoking. Nothing has been spilt on the exhaust and the smoke isn't coming off the down pipe, could be off either the inlet or exhaust manifolds as they are both very close behind the heat shield. The fact the car runs better on choke make me think there is an air leak somewhere leaning the mixture. Coolant Temp seems a bit high also

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Welcome to the madness, mayhem and merrymaking that is Autoshite.

 

Ace car by the way, love the dash! Seems like you are working your way around the various bits and bobs in a most satisfactory manner. The Seller seems to have been a bit of a cunt.

 

We need moar pictures.

 

Whereabouts are you?

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Welcome to the madness, mayhem and merrymaking that is Autoshite.

 

Ace car by the way, love the dash! Seems like you are working your way around the various bits and bobs in a most satisfactory manner. The Seller seems to have been a bit of a cunt.

 

We need moar pictures.

 

Whereabouts are you?

 

Thanks for the words of encouragement. Yeah seller did lie his arse off lol  :-D

 

I'm in Bedfordshire, near Bedford. I will endeavour to put a few pics on as I continue the work

 

A friend of mine suggested smoke could be leaking dashpot oil. And since I just topped up dashpots after putting carbs back together that would make sense. They were empty before

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On the heatshield...... IIRC - MGBs have a very similar shield in place and it does look to be hardboard but is some other fibrous material...... no clue as to asbestos content and I haven't removed one since the MGB that terrorised my life in 1993. EDIT  -I think my big six Trump had similar too........

 

Always loved these but never been near a genuine decent example - always rotten when I had funds and time to hunt them down. Can't find a single one over here though :-(

 

Welcome and good luck with the smoking bits - just amazed it isn't the Lucas gremlins at it ;-)

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Kevin is a great runner. No oil pressure atm though, so have another engine to go in. ;)

 

Ouch. The Twin Carb has a slightly different camshaft I believe. At least it has a slight difference to valve timing, so I assume that's how its achieved. When you swap the engines over I guess you will re-use the head from the HLS?

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On the heatshield...... IIRC - MGBs have a very similar shield in place and it does look to be hardboard but is some other fibrous material...... no clue as to asbestos content and I haven't removed one since the MGB that terrorised my life in 1993. EDIT  -I think my big six Trump had similar too........

 

Always loved these but never been near a genuine decent example - always rotten when I had funds and time to hunt them down. Can't find a single one over here though :-(

 

Welcome and good luck with the smoking bits - just amazed it isn't the Lucas gremlins at it ;-)

 

I think heatshields must be original then. I thought they were home made because they looked like hard board, but they are a complex shape and I was wondering how anyone could fabricate the curves in them lol  :-D

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