Project 1974 MGB GT - The Mustard (Mit) Mobility Scooter - 6yrs ownership & the end is potentially nigh!

[tooSavvy]

Oh and that is not an Engineers scraper.

At the Vickers Apprentice school, Scotswood Rd, we took blunt files and linished a flat across the end face + brazed a carbide lathe tip on >> then polished on the tooling stone grinder.

 

Fabulous scrapers and never went blunt (vs carbon steel)

 

 

TS

[SiC]

I've decided I'll pop down to Moss when they open again on Wednesday and get this:

 

https://www.moss-europe.co.uk/overhaul-kit-wzx1850x.html

 

Hopefully replacing the main bits that can cause me woes. The throttle shafts seem alright on mine and they reportedly to not cause a problem on HIF carbs - only HS and previous. The rubber seals though can perish and leak. Also the rubber seals on the choke assembly seem to leak after ethanol fuel exposure.

 

Worn needle valves does seem to be very much a thing on HIFs. There is a "premium" replacement called the Groose valves, however recent posts in the MG forums have been saying quality has dropped in them and the standard type has increased.

[Rusty_Rocket]

I'd say that's a really good idea, that way you can rebuild them and forget about it.

The HIF SU is a good reliable carb, it honestly is.  Like you say, they don't suffer spindle/ body wear like the HS type with external float chambers.  I'd say HIF's suffer with flooding just as much as the HS's do, but you won't notice as much as they don't piss fuel all over the place when it happens!

Many a Mini has been lost by the needle valve letting fuel flood the chamber, leaking petrol directly onto the exhaust manifold...

[SiC]

 

 

I'd say HIF's suffer with flooding just as much as the HS's do, but you won't notice as much as they don't piss fuel all over the place when it happens!

Many a Mini has been lost by the needle valve letting fuel flood the chamber, leaking petrol directly onto the exhaust manifold...

That's really interesting that you say that. I was expecting fuel to be really running out if the needle is leaking. Thus the pump running frequently.

 

On the MGB, the carb overflows run down in pipes, past the manifold and to the floor. So I'd probably not have seen them overflowing. Especially if it's a dribble rather than a continuous flow. I'm trying to remember what happened on Friday. I have a vague recollection that the pump was clicking every couple of seconds when the engine was running. Which is possibly more than I would expect.

 

The needle valves do have a very small lip to them, but surely that shouldn't matter too much if there is a matching one on the seat? But I reckon the spring isn't strong enough either. Especially against a new, more powerful pump (it has one of those blue Hardi on it now).

[Rusty_Rocket]

Any wear lip on the needle valve means it's very worn.  My eyes aren't good enough to see the pictures properly on the phone, but any visible wear at all means it's very worn!

Yes, with a fuel return, you probably wouldn't notice the carbs flooding, apart from the running problems.  At least you have a return system, early HS's don't hence the fuel pissing everywhere.

If you think about the wear on the needle valve and seat, if both are worn, the float will be sitting higher than it should, particularly if the level hasn't been set for years by bending the metal arm.  The needle valve's spring should be strong enough to hold the float completely in its lowest position with no fuel in the chamber.

[SiC]

Sorry I didn't mean a fuel return, just pipes that directly dump on the floor.

 

I'm going to take out the needle valves again to have a closer look in daylight and run my finger nail across it. Hopefully this is the root cause of the problem.

 

There is screwdriver pry marks around the base of the float chamber, so it looks like someone has been in here before. Also I'm going to try and get a new set of spark plugs today and see if I can at least get it running.

[SiC]

This is the rear carb.

 

It's really hard to tell with the naked eye but just about is possible to capture with a phone camera, but there is a ever so slight lip. You can feel it with a screwdriver edge but not fingernail. There is also this slightly more polished area.

 

 

 

The seat is hard to tell if it's pitted or just dirt down there. I can't seem to shift it with carb cleaner from a can and I don't have any compressed air.

 

Either way, as I'm not 100% sure I'm going to change them. I mean I've chucked enough money at this old heap, so what's another 50quid to chuck on the bonfire?

[Guest Hooli]

They don't look too bad to me, but then I've seen ones that look better than that leak too. Replacing them seems a good idea.

 

 

There is a bank holiday tomorrow, you could get it done ready for work on weds....

[SiC]

So what have I done today?

 

Bought and fitted a new battery.

 

Previous was a 063 fitted a couple of months ago by the last owner but didn't fit properly. The common advice seems that they should fit ok. Problem is, most have tabs on the bottom that foul the sides. To get around this, the last owner put all the wood crap you see in the picture above. The cardboard and ply sheet was the clamp against the metal cover to stop it shorting and hold it in place. Not ideal.

 

I'd previously bought a battery clamp but couldn't fit it with the old battery. This new battery is a 202 size (£40 from ECP with 40% code) and fits a treat. Capacity is slightly less than the 063 but the MGB isn't exactly electrically heavy vehicle.

 

Next up was something that six-cylinder reminded me that I needed to do. I originally planned to put an additional earth lead on the alternator side. However as that was fitted, I couldn't be bothered to remove it again. Instead I cleaned up the existing lead and doubled up with a new one.

 

It'll be interesting if it runs any differently.

 

Finally I've started putting the carbs back on. They'll have to come off again to replace the float needles during the week, but I'm desperate to know if the engine still runs. I'll let the carbs fill up and then clamp the fuel line again to stop the engine being flooded.

 

Speaking of clamping the fuel lines, I've left it clamped the whole time the carbs have been off. When turning the ignition on I get a quick single clunk of the pump. So hopefully this means the fuel system from the pump to the carbs is possible to stay fully pressurised without leaking.

 

With the carbs connected I often got a good 3 to 4 clunks when turning the ignition on after being off for a couple of minutes. So I'm getting pretty certain that the carbs are overflowing and have caused the problem on last Friday. I'll be really interested to see how they react (or if anyone else could tell me from their experience) when full and left for a couple of minutes. I assume that the carbs should be capable of holding fuel pressure for a few minutes?

[SiC]

They don't look too bad to me, but then I've seen ones that look better than that leak too. Replacing them seems a good idea.

 

 

There is a bank holiday tomorrow, you could get it done ready for work on weds....

No work for me this week and after family duties over the next 2 days, I should have plenty of fiddle time. Handily Moss is open during the week too, so I can easily grab any parts I need.

 

I'll then just have to gain enough confidence to go back out in it and hope it doesn't breakdown again. I can only take so much frustration and inconvenience from breaking down.

[Zelandeth]

Personally with regards to earthing, I usually stick a nice beefy earth strap somewhere I can readily see it and easily get to it.  By making it readily serviceable you therefore ensure that it will never require any attention.  Ever.

 

Realistically though that will probably last at least another ten years though.

 

Given the carbs have been giving trouble, I'd tend to suggest changing the needles and seats.  At least you know you're starting from a level playing field then.  Plus you know once they're set up right they shouldn't need faffing around with again for a while then.

[SiC]

Put the carbs back on - those bottom studs are fiddly as anything to get to. I reckon it's why old men buy these cars but never drive them and only polish them. Getting to some of the fixings on the car is rather difficult.

 

Anyway, powered the car up to find the front leaked carb from the base out of the seal. When I was reassembling them, I couldn't get the new rubber seal back on, as for some reason it had stretched.

 

So I used the old seal. Which was a mistake. Anyway I took them off again and trying even harder to get the new one in again.

 

Powered the car back up and checked the overflows for leakages.

[Video]

 

Even if those needle seats are worn, they seem to be still doing their job. I sat 4 minutes with the ignition on and never had another pump click. I wonder if it was that black blob in the needle seat that was there all along and causing the blockage?

 

I tried turning it over but it wouldn't run. It tried to fire and run but couldn't quite manage it. Not sure if it still wet inside or something else is going on.

 

Turning over with no plugs doesn't spit out much fuel. Barely noticeable. I have some brand new plugs to try next. Also put on my spare distributor cap. The rotor arm looks fine and is one of these magical red rotor arms.

 

I'm still going to get a service kit for the carb, even though they appear to be behaving themselves at the moment. I'll probably get a spare coil too, just to have a spare and rule that out.

 

Nearly there but no cigar.

[Skizzer]

Maddening. On the plus side, when you do finally crack it, you'll have renewed most of the fuel and ignition systems so it should* be nice and reliable*. (Terms and conditions apply.)

[SiC]

Maddening. On the plus side, when you do finally crack it, you'll have renewed most of the fuel and ignition systems so it should* be nice and reliable*. (Terms and conditions apply.)

Then I'll probably end up selling it!

 

If it was after Easter, this would have been up for sale/sold and Breadvans Sprint would have been purchased + sat on the drive...

[captain_70s]

If you find MGB tinkering irritating don't get a Doloshite! All the joys of twin carbs with a more complex engine and plenty of BL engineering "solutions"!

[Mr_Bo11ox]

This is annoying me and it's not even my friggin car. These old carb-and-points set ups were dog shit when new, and now all the new parts are made from chinesium it's even harder. The only way is to plough on like you are doing fiddling with it. You will soon get it running, then you've got to use it a few times a week to build up the karma!!! Defo get a decent electronic ignition set up if you haven't already. fucking points are ridiculous in 2017, only the most luddite beardy car-show mental will persevere with those nowadays.

[Guest Hooli]

I'll disgaree there.

 

I 'upgraded' my Bonnie to points as the leccy ignition was so unreliable, I was replacing the damn things more often than the service time for points.

[Angrydicky]

Yeah there are shit leccy ignitions and good ones. Powerspark is the best, never had any issues with them and most of my classic car owning mates run them with no problems.

[Mr_Bo11ox]

Admittedly I suspect electronic ignition sets are as prone to chinesium content as replacement sets of points & condensers. I guess it's a case of buying the right one from the right place.

[danthecapriman]

I've got Pertronix leccy ignition in the Mercury. It's brilliant, not cheap but works perfect and fits well and easily. They seem mainly American though.

I've got a kit (can't remember the brand) for the Capri too when the time comes. I'll get it running on the old points/condenser first as I know it works on them as they are then swap over once I know everything else is ok. I'm done with points/condensers now. Points are ok but the modern condensers are utter shit. I've had loads that were faulty straight out the box. It worked ok when new and there weren't many affordable alternatives but things move on and since it's all hidden from view in the dizzy it seems silly not to take advantage of modern electrics, especially when it makes such a big difference.

Of course it's like many things, nothing is fault proof and even these can be faulty. But on the whole I find they're a massive win.

[Guest Hooli]

The crap ones I had were a series of the highly regarded (always recommended on classic bike pages) Boyer Bransden. I was lucky to get 2k miles before they blew the output transistors even though they were fitted exactly as the instructions said.

 

Odd really as the same place make a replacement reg/rec that allows you to run with no battery and that works perfectly. I've added a battery since due to low voltage at idle fouling the plugs, especially if the lights are on.

[SiC]

Just speaking to my old man about this. He was a mechanic around the time this technology was about. One of the reasons he stop being a mechanic was getting fed up fixing the same old problems and welding up all the holes. Consequently he can't see why anyone ever would want to own a 70s car.

 

Anyway he reckons it's probably more timing and an ignition problem. Especially as it's backfiring. Possibly even the condenser. His one memory form his old lecturer was "Getting a good condenser is like finding a good partner. Once you get a good one, you need to keep good hold of them."

 

Thoughts on the problems I've had being the condenser? I'll check the capacitance later today/tomorrow once off family duties.

 

I'm wondering if the modern condenser has kicked the bucket. Luckily I went on a rampage at the NEC and have plenty of spare points and condensers. Hell, I even have a whole brand new spare 45D distributor that I bought!

[Guest Hooli]

Sling another one on as a test, it's the easiest way to know.

 

I seem to recall that with the ignition on if you open the points & see a spark it's proof your condensor isn't working.

[danthecapriman]

I've had exactly this on the Mercury. It was working well, put it away for winter then went to use the car and it'd either run awfully or not run at all. Just cranking over and over. I tried loads of things to sort the problem before finding the condenser was the most likely culprit.

I changed the dead one for a brand new one. Same. That was brand new and fucked straight out the (Indian!) box. Stuck another new one on of a different brand (Chinese!), that worked for a while then fucked up itself. Then I got angry and got a cheap electronic set up which didn't even fit properly so that went back for refund and then finally bit the bullet and bought the Pertronix electronic kit from the states. It fits perfectly and works as it should faultlessly. It's been in there a couple of years now and I've never touched it since.

 

The old points system was always the weak link on old cars. It was the best/cheapest way to do the job, at the time there weren't the electronic tech we have now so really it was all that was available. It's easy now to stand back and criticise it but plenty of cars used it for many many years and it's worked all that time. Even now there's loads of cars that have survived to now still using it. The problem comes when your using a system like that that's prone to damp, wear, etc etc anyway then try adding new components from shit cheap sources that just compounds the problems. It's pretty poor state of affairs really in this day and age with all our tech and know how that the quality of such stupidly simple bits of kit like a car condenser can't be made in a decent quality that it isn't a complete lottery of wether or not it'll work.

I must ad,it if I have points and condenser that work I tend to leave well alone until such time as it doesn't anymore. If you change them at every service like you were meant to there's every chance the new set will be worse than the old working ones. That's why I change to electronic now, it just makes more sense to me and saves me getting angry!

[busmansholiday]

[quote name="Mr_Bo11ox" post="1383589" timestamp="1514204006"

 

only the most luddite beardy car-show mental will persevere with those nowadays.

 

Actually I don't have a beard and showing any of my MG's would get me seriously laughed at, but I do like points, and the rest of the old world shite.

 

If I had time, and my tools, on my way back north from the English Riviera at the end of the week I'd call and give SIC a hand.

[Zelandeth]

The thing with electronic ignition setups is there are good and bad ones.  A good one you can literally fit and forget.  

 

The difference, especially around town and at idle is quite obvious.

 

Still never going to forget when I fitted the EFi setup to the Lada and turned the key with everything lashed together (seriously, the ECU was balanced on the windscreen wipers and I'd stolen a power supply from the rear window heater relay, so that was my ignition switch...), and it just started and ran the smoothest I could ever have asked for.  I was bloody stunned!  I was expecting a half-hearted sneeze or if I was really lucky it would start but run like a sack of spanners...nope!

 

I only had a single gremlin surface during the shakedown which was pretty quickly traced to a vacuum leak.

 

I reckon the sweet spot for ignition systems was the late 80s.  Where they'd done away with the points etc but still used the distributor.  Less prone to randomly falling over and dying like direct ignition coil packs can be, but more likely to just work out the box without being fiddled with every other week than a points based setup is.

 

Only problem I've ever had with that across three Saabs has been once when I was supplied with the wrong rotor arm - that took me over a month to figure out because I'm an idiot.

[Mally]

If you put the 'brand new' distributor on make sure it has a red rotor arm.

Mine didn't and broke down first time I fitted it.

I went back to manufacturers original.

......For a while...............then I got fed up and sold it............. "there's a brand new distributor in the boot".

[mercrocker]

Every time I buy anything with a 45D or 25D distributor I hurl the points, condenser and rotor arm over the hedge and fit either a Pertronix or AccuSpark trigger and module together with a red rotor arm.  

 

Any other combination will give you trouble in short order.  

 

Theoretically, these electronic systems can give trouble but I haven't had any.   If it was me I would replace the whole dizzy as well for what they cost, you can buy them complete with the electronic guts in them.    Trouble-shooting, should it become necessary is not made any more difficult by the conversion, it looks the same as stock except your head won't be under the bonnet.  

 

Just be sure which polarity you buy it for and watch out for leaving the ignition on as this can fry the modules.   Traditional ignition components are so woefully shit these days it isn't worth pissing about with them.   

[SiC]

I've been thinking of getting this:

https://www.moss-europe.co.uk/points-set-contact-breakers-high-quality-gcs107hq.html?assoc=536599

 

And this:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F391439313553

 

I know Dollywobbler has mentioned that he likes that module and has one in his 2cv and now invacar. For me, I like the idea of them more than the a module inside the distributor.

 

The problem with a distributor based module I see, is that it's in a place that gets hot, vibration and very electrically noisy. Not best places for sensitive semiconductors. Also the transistors in them can't be that big to fit and have to dissipate their heat through the distributor. This is what I reckon kills a lot of them.

 

That external module on the other hand lives externally and physically bigger. So it can dissipate heat better, less noise and vibration. What damages points is the fact they've got to switch 5-8A of electricity if connected directly to the coil. This is what pits and wears the contacts. Where as that module can reduce that load way down (as the module is doing the heavy switching) to around 100-200mA. It's possible to have the points switching almost no current, but you don't want no sparking as the arcing helps keep the contacts clean.

 

If you look at the way car manufacturers went, most went with the external module first (ignition amplifier). Later then progressed on to have that and also remove the points with a hall effect sensor.

[SiC]

Interesting article:

http://www.nonlintec.com/sprite/cap_failure/

 

Could explain why Moss feel confident that this "high quality" condenser has never failed for them:

https://www.moss-europe.co.uk/condenser-lead-25d-high-quality-gsc111hq.html?assoc=534797

 

Definitely the next thing I'm going to check is the timing. Then try replacing the condenser and maybe even bung one of the spare points I have on for good luck.