can't go above 60

[little_pete]

Thanks for your help

My concern is the sudden blackened plugs in the 3 (and somewhat in 2) compared with relatively good looking plugs in 1&4 . There's been a lot of choke idling and previously the carb was too rich hence the soot on the rest of the plug, but the tips are starting to show a better colour, where as 3 just looks totally different. I know theres always a difference because of the way the head is but I've never seen it quite so bad. I might take it in for a second opinion at least with a more experienced ear they can make sure the timing is correct and hopefully determine the rumbling.

[bmcecosse]

Take it for a good thrash - a good long uphill gradient is ideal - and switch off at speed and drift to a halt - and whip the plugs out. How do they look then?

[little_pete]

Thats what I did originally, went to get petrol, my house is on a hill gave it the beans on the way up but it was rumbling a bit, took it home backed off the timing and checked the plugs. Swapped 1&3 and weakened the mixture. Then I went on a long flat straight and gave it some welly at 60 miles an hour for a bit and then turned off the engine at speed checked again to find the above pictures drove home carefully as I didn't know whats wrong.

[bmcecosse]

Do you have any other Axx needles you could try?

[little_pete]

I have an AEM from the original carb (one of the later Minis just before SPI I think it's 1990)

[bmcecosse]

That will be more suitable I think - try it! See the difference on minty lamb.... http://www.mintylamb.co.uk/suneedle/

[little_pete]

Nice tool! but I don't know what to do with it.

I presume larger diameter is a weaker mixture?
So is the AEM weaker overall and much weaker at the top end?

[bmcecosse]

I had hoped the link would throw up the comparison I had on my screen with AEM and AAA. But if you do that - you will see there is little difference at first - although AEM is always slightly weaker until about half way along the needle - when the AAA gets to be quite a bit richer. No harm trying the AEM !

[little_pete]

Yeah I worked it out no problem exactly as I understand it, I'll try it tomorrow. Thanks

[little_pete]

OK an update, I changed the needle and of course messed up the mixture, I foolishly started doing the mixture when it still wasn't cold ended up being too rich then I put it down too much. still have white plugs but getting darker. I was driving carefully until I got the mixture close. No.3 plug started to get a grey tip showing signs of life. I thought changing the lead to the old lead (changed only a few months ago) and fingers crossed it looks better under load still lots of soot, but the tips getting white. Overall still too lean under load will fiddle more (I've never got the lift carb piston on idle to work, it just wants to stall).

I backed off the timing some more but this is starting to really effect the idle speed.

Also I have smoke, it's quite white maybe a hint of blue and it lingers so I think oil. This is how it happens, idling setting up carb so rev a little every minute. After 10 minutes there is the smoking coming from the exhaust A quick high rev gives a nice plume of the smoke and then it's clear until I leave it for another 10 minutes and the smoke occurs again.

I've taken the filler oil filler cap off (little whisp when taking off, but every car I've owned has done this) then I give a quick high rev, no extra smoke.

Valve stem guides? (I hope so as I'm changing the head anyway)

Performance wise: I'm going 70 plus until I hit a bump and then slow down again due to my fear. Less severe flat spots. Probably as good as it will get with a random needle. I still need to richen the mixture.

Thanks for all the advice

[bmcecosse]

You should set the ignition timing for 'best idle' and then check it's not pinking. Then the mixture - you only lift the piston about 1/8" - any higher and it will always stall. Is the vacuum advance working ok?

[little_pete]

OK the rumbling was proper knocking/pinking, took it to another garage who have set the timing and driven it, said it's driving very well, they don't seem too fussed about the sooty plug, said it's probably burning oil on that cylinder but unless I want to strip the engine then don't worry about it for now. Will get the cylinder head changed and hope that worn valve stems etc are the cause of the oil in the cylinder.

Thanks for the help. I'll report back with the new cylinder head, though quite happy with the power now the timing is correct, could just do with a bit more oomph on inclines, I feel the car struggles to keep a good 50 on some steeper hills and I don't really want to scream up them in 3rd. I'm slightly spoilt by my modern being a turbo diesel Alfa for that car the world seems flat.

[bmcecosse]

Well yes - it's not going to match a turbo diesel......unless you FIT a turbo diesel..........

[little_pete]

Just been for a 300 mile jaunt up to Manchester up and over the pennines the only thing that slowed me down was a kia picante.

Getting brake judder 60-40mph below that the brakes are fine. I normally try to use the engine for this kind of braking but there is the odd occasion where it is needed and obviously it's not normal. Suspension bushes? I get the odd knock but only on potholes, not during normal driving. I have no idea if the wheels are balanced but at certain speeds on the motorway the car is more shaky.

Major issues was the fuel it was using, (lots of it) and the little petrol pump ticks away quite quickly.

I had a look at and manifold gasket appears to be wet like it's soaking up petrol. so I have a problem around this area, but why so much fuel? surely that should give me leaness I checked the plugs they are pretty dark rich if anything and no.3 is still black. Float valve in the Dashpot? I fitted a new valve and set it with a ruler as described on the SU HIF instructions, perhaps I did it wrong or the float doesn't actually float? Doesn't appear to be any evidence on the overflow pipe.

I had no issues with the performance of the car except the fuel consumption

Oh the gearbox while mostly fine sometimes it's difficult coming out of 2nd, and at one point I couldn't get it into 1st or 2nd at the lights. But most of the time it's fine.

[bmcecosse]

In reverse order - perhaps the clutch is not clearing properly - how much free play at the pedal? And try an oil change in the gearbox - 20W50 is fine, although original was SAE 30 spec. Dark plugs and heavy fuel consumption tell me too rich - weaken it. How 'bad' was the consumption? 25/30 mpg if being pushed along and hilly is to be expected...... It's very easy to static balance Minor wheels on a front hub - and usually that is enough. Rumbles when braking could very well be suspension bushes - worth changing to polyurethane, or just worn shoes and /or heavy dust accumulation in the drums.

[little_pete]

Will take a look at the clutch I was going to grease all the mechanism from the pedal as it has a dry creaky feel. Hard to tell from memory about an inch before I start getting to the clutch. doesn't appear to slip at all. pressing all the way down slows the idle somewhat I was told this was bad so always take it out of gear whenever I'm stopped.

More a visible shaking of the steering wheel even with my hands on it than a rumble.

Static balance is this just spinning the wheel and seeing that it never tends to land in the same place?

I get lots of clicks of the petrol pump when just pootling around even a series of 4 in a row, which is why I was thinking the float/valve in the Carb and the wet gasket isn't right? I had taken it to a (different) garage who set the timing as it was indeed pinking heavily (more than a little ping) and a they had set the mixture with an analyser before the journey I had driven it about 20 miles and the plugs were grey white (little lean in my opinion) (except my problem no.3) and i haven't touched the carb.

[bmcecosse]

Yes - spin and settle the wheels - add weights as necessary. Plugs sound ok then? 'Wet' gasket can't be right - you need to find out what that is......

[little_pete]

One of my front wheels has something inside the tyre, you can hear it rolling around when you spin the wheel! or when it's off you can bounce the wheel and feel it bouncing around. never seen this before. I'm expecting some stray wheel nut.

Also one of the drum brakes has a sizeable chip out of the rim, doesn't go onto the braking surface I imagine somones tries to lever it off and chipped it. probably not great for balancing.

The drums grind in one place so I can't do that static balance. untrue drums?

On other notes my epic engine woes. my Manifold gasket is still sopping wet, found a hole in my carb someone has blanked off a port below the petrol overflow tube (normally to connect the fuel to a second carb) but it leaks, it's very near the top of the chamber but still shouldn't be there. I really don't see how this can make the manifold wet as there is a heat shield in front of the carb which would surely catch any drips. everything else appears to be fine... needle valve is new as is it's seat, the float floats in water and doesn't appear to have a leak the jet is new. Took off the manifold and re attached it. Just got to plug the hole in the carb petrol's expensive!

[bmcecosse]

Slacken off the brakes to do the balancing. They usually touch slightly - but you should easily get a good idea if there is any wild out-of-balance. Thing inside the tyre could be remains of old valve - or a puncture repair, or could it be water - used to detect a leak and some has seeped inside. Probably best to pop the tyre off a bead to find out what it is.

[little_pete]

OK so been for some proper runs with the plugged up carb, running very well (70+ is easy for the car now but I only do that to test it and cruise around 60 sometimes overtake at 70) but still the fuel pump is ticking more than I thought it should. I've done no fuel calculations yet, mainly my fuel gauge is buggered (only reading 1/4 when full) and so I top it up wherever possible.

Is fuel vapourisation a real possibility in this weather? I've read people suggest that it's unlikely to happen on a minor with the huge bonnet space.

Here is the behaviour:
- With engine off the fuel pump ticks rapidly to fill the float bowl. OK this is normal
- After a few seconds the fuel pump will then tick again wait a second tick again (still with the engine off) I thought this would suggest a leak?
- With the engine on idle the ticking gets more rapid. OK this is normal sometimes if I leave it idling I'll get the rapid ticking every now and again
- under light acceleration I get a burst of ticking. OK it needs more fuel but seems to be trying to pump an awful lot of fuel in there?
- under heavy right cornering at slow speeds (round about etc) I get rapid ticking though I'm not really accelerating much just enough to corner well.
- under cruise it ticks like idle
- up hill more rapid ticking OK i presume
- cruising down hill 4th gear no accelerator or very little still ticking a little more than idle

The carb is a HIF38 the pump is an SU I think it's a 'pointless' one as I can't seem to remove the back to clean anything. (pump is apparently about 2 years old and from the looks of it's shiny newness and the newness of all the pipe work I'd guess this is correct)
The carb I've put a new needle and seat in plus a new filter inside it (and replaced all gaskets). Set the float level to the body of the carb, submerged the float in water, it popped straight back no signs of a leak. Fuel pump filter is clear, replaced pump to carb pipe. looked underneath the car for obvious leaks to the fuel tank. plugs are on the lean side if anything. I've reattached the inlet manifold and it seems to be better (the wet gasket never fully dried, perhaps it's oil (I thought petrol would evaporate at least over a few days), it has been to a garage I don't know if they sprayed it to test for leaks)

I'm going on a long journey and want to make sure I'm not squirting expensive petrol anywhere other than the engine.