Hi all,

I have a 71(ish) mini and I have just gotten it running after it was sitting for around 13 years.

I have dual HS4 carbs, and to be honest we don't actually know which engine the car has. The previous owner said it should be either a 1380 or 1275.

I followed some stuff i read online, adjusted idle, tried the colortune system. I tried a unisyn device but i can't get it working properly (the level never rises)

The car idles horribly and surges up or dies down and stalls but oddly enough it does drive well after it gets going.

Any advice / links / procedures?

Lastly here are some engine bay shots, maybe somebody can identify this engine





thanks

 

a few questions cuz it certainly appears the car is modded so we might also try to determine if it is a re-vin (I think this is a later year car ... re-vin to get in the country ... then heavily modified .... This is not a horrible thing .. until you start trying to sort it and buy parts!)

I see a KM1 grill and mustache trim ... what tail lites? rounded or rectangle (picture will help us ID)

Got an interior pic or two?

How does the dizzy attach to the block (an indicator of an A vs A+ engine ... a 1380 would have to be A+ which would be a re-engine in a 71) if there is a bolt on a collar around the shaft it is an A ... if a bolt goes thru a single hole in a finger clamp, A+ (picture) .... also if the dip stick fits into a tube attached to the block, A; if the dipstick sits flush to the block, A+

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#1 tuning rule: NEVER mess with the fuel system until you are 110% sure the ignition is spot on.

Have you checked the timing and if so where is it?

Have you replaced the points? (I recommend ditching the points and going Pertronix BUT WARNING you need to know FOR SURE what dizzy you have and part of this is knowing what BLOCK you have {A or A+})

coil looks new in picture but is it? Also question dizzy car, plug & coil wires, and dizzy rotor.

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haynes has a carb adjustment procedure .... have you followed one? Brookstone also has a good book about the SU carbs but the 'seat of the pants' adjustment proc' is the same as what's in Haynes.

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electric fuel pump or mechanical? From the hose routing I suspect mechanical .... are you sure fuel is flowing well?

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are you in the US?

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many Mini experts say that you can never properly tune the SU carbs except on a 'rolling road' aka a DYNO, and with an assortment of 'needles' in hand.

What they are saying is ..... if the prior owner swapped out the engine, and changed the carbs and air cleaners and maybe even the exhaust then the car will NEVER run right until the proper needle(s) for the SU carbs are installed. In an SU the running profile is all in the needle ...... just changing to a cone filter on a single carb car requires a different needle from stock . . .

In the UK you can find shops that have this expertise (I read). In the US there are a few shops but for the most part you can try and talk it out with one of the major part suppliers who are talk friendly. I've had good experience with Mini Mania and Seven Enterprises. When I lived near VA Beach, Abacus Racing was a godsend
http://www.abacusracing.com/ The owner collected Healey's ....

 

1. Rectangular lights
2. The block has a threaded part coming off and it's held on with a nut. the dipstick sits flush.
3. Have not checked timing yet
4. coil is not new, just cleaned. Same with rest of it. We just cleaned it, and it all looks to be in good shape.
5.I followed the stuff in the haynes manual... it still is not right
6. Mechanical fuel pump. It does seem to be working correctly. We removed it, cleaned it reinstalled it.


I am in the US. The original owner imported this car from the UK.

I am in Maryland. If you know a shop around that area which i could take the car to get properly tuned up that would be fantastic



Also, i rebuilt and cleaned the carbs with a lite carb rebuild kit from 7mini. It had some new springs, the thing which goes from the float to the needle and a few other bits.
Kit didn't have needles so whatever it had is still in there.


A few more pics as well

 

1. Rectangular lights

OK .. we confirm that the front metal has been replaced to make it look like a MK1

2. The block has a threaded part coming off and it's held on with a nut. the dipstick sits flush.

Not sure I follow your "nut" description, but if the dip sits flush to the block it sounds A+ to me .... if it IS a 71, it is re-engined . . .


3. Have not checked timing yet
4. coil is not new, just cleaned. Same with rest of it. We just cleaned it, and it all looks to be in good shape.


DO NOT FUTZ with fuel system until you are 110% sure ignition is right. I don't say this because I read it ... I DID read it, and verified it ... MANY times!

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I'm reading "it was sitting for around 13 years." as meaning the pictures I see are from when you got it .... but how far IS this car from the 'not running for 13 years'????
5.I followed the stuff in the haynes manual... it still is not right
6. Mechanical fuel pump. It does seem to be working correctly. We removed it, cleaned it reinstalled it.

are we just trying to debug a modified motor and everything else is 'colored bubbles'? ... That is NOT a 71 interior!

 

OK i should have clarified a little bit.

Yeah it does seem our car is a combination of many years?
We also think it was just registered as a 71 simply so it could be imported under the 25 year rule.
Who knows what year it ACTUALLY is, but yes it's likely got nothing 71 about it.

The photos are not from when we got it, they are some in progress photos.

The whole process so far has been:
1. Got car, it was sitting in a garage and had not run for 13 years approx. removed fuel tank and saw it was rusted to crap. Sent that out to be refurbished.
2. removed carbs and fuel pump. Cleaned the pump and reinstalled it with a new gasket
3. Got the carb rebuild kit, took apart the carbs, cleaned them and rebuilt with the kit.
4. replaced all dryrotted hoses, cleaned fuel lines. Flushed cooling system, clean radiator, replace radiator fan. New belt as well.

I'm sure im missing a few things but that's the main stuff done so far.

But yea, the main issue to debug right now is the motor. It's just not running correctly at all.

For the carbs i believe what i did was screw the mixture screw all the way in, then back out 2 turns just like it says in the Haynes manual. That worked for the initial startup, and we actually had it idling somewhat decently and consistently.

We then checked the mixture with the colortune kit and it was too lean, we adjusted it till it was blueish like the instructions say, but then the idle was again terrible.

So it sounds like the next thing to do is timing, so we will try that next.

 

So .. you have done fuel while ignoring ignition .......

if you ain't got good spark you can't run well . . .

timing and points for sure ...... probably a coil

I had mine for a few years running OK when I finally went to the Pert' with a new cap, coil, rotor, plugs and wires ... on top of a timing check

OMG what a difference ....

best money I've spent on mine - which I've owned since '04

most ignition parts are not expensive ..... but do not age well . . .

 

McGee's Custom Minis in Annapolis - John McGee - if he's feeling better now - he was in a bad Mini accident recently.

 

As far as a tune up goes, I always start with a good valve clearance adjustment, if you have a tight valve it's never going to idle correctly......


On the Unisyn, are you aware that you can turn the center plate in to give a smaller aperture, then you can get more vacuum past the plate and cause the bubble to rise in the tube?


Also, first release the linkage connection between the carbs so you can adjust them independently, then make your adjustments.


But, check valve clearances, then ignition, then carbs last.

 

Thanks, i'll look at that shop. Maybe its better to have a pro do it.

I did release the linkage connection and I am aware about the plate which turns. But, it's weird. Now what it's doing is when i turn it to the point where the thing rises, the idle shoots up to like 4.5k and kind of just stays there until i turn the car back off an on, then it's back to a low idle.

I'll check timing, ignition etc and then go back to trying carbs again last.

 

Check for play in the throttle shafts, that can screw with an idle too, as sometimes it causes the throttle plates to hang open.....although I've never had one go to 4500 from that. You did leave all the return springs on, right? It should have one on each carb and one for the middle link too......


Make sure all the gaskets between the carbs and manifold are good and the carbs are on tight - nuts cinched up etc. Make sure the manifold to head gasket is good too. Check for any open vacuum ports......

 

Return springs are on, throttle dosen't have any play that i can see. The gaskets between carbs and manifold also are brand new, no leaks.

It's weird, when the throttle things are totally closed the idle still shoots up and i just can't figure out what is causing it.
When i first start the car it's fine like i said but then it just rises up.

Maybe there is a vacuum leak that i need to find.

 

That's what it sounds like to me....or maybe a loose breaker plate in the distributor.


What is the plug behind the left side carb? looks like it's temp sensor in the manifold? Wonder if this was an SPI car converted to carbs?


Are there big fat washers behind the 4 center nuts that attach the intake and exhaust manifolds? Usually the intakes are aluminum, and they're thicker than the exhaust, so you need a fat washer to put the right amount of tension on the two disparate thicknesses.


Does the dist hold down just have one bolt or two?


Is there a crank sensor mounted below the starter - into the bell housing?

 

dizzy clamp for A+





for A




pictures from MiniMania.com

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I too have parts from many years. I refer to it as an ItsAbitsA

It's a bit of this and bits of that ..... but the last MOT document it had when it arrived in the States said it was a 1979 and that matches the 'marks'

BTW ... look at the boot lock plate ... you should see some numbers stamped. This represents week and year of build ...



it is not a part commonly replaced. Similar mark can be found on the wiper motor

 

Hi 71:

You could have a host of issues going on here, I assume it has fresh fuel in it. Did you take the float lids off the carbs and check them. Could be clogged up after sitting for many years and need to be cleaned and or rebuilt. Duel HS4's are a little much for the 1275 or 1380 engines, but are used on them, just need to have the proper needles in them.

Give us a call and we can go over some other possibilities.

Ed 800-946-2642

Drive Hard. Drive Safe. Keep Grinning.

 

Wheeler dealers TV show just did an old Volvo with dual SU carbs, pretty interesting how he tuned them. Worth a watching!

 

you say you 'rebuilt' the carbs ....

So you are SURE the pistons are lifting freely ..... no gunk in there ... and what oil did you fill the pots with?

{after my first rebuild the car ran like crap and the carb leaked .... so I did it again .....

When you are sure everything is right
and the program does not work
something you are sure of
is wrong }

I see a "valve cap' on a line you are not using. Suggestion ... take the cap off and see what happens . . . made this mistake on mine. put a plug on an unused intake line from emissions system, but blocking it caused BIG problems with my HIF-6. Soon as I took plug off .... major improvement. the line needed to suck air .... intended for dirty, but none was bad . . .

 

Those caps are where the breather pipes should go for the crankcase breather, they are before the throttle plate so they should not affect the idle at all.

 

intended for dirty, but none was bad
doesn't cost much to try now does it?

 

Car gas fresh new gas. I took float lids off and checked them, also replaced the pin things inside. And cleaned them out.

Piston lifts freely. SU dashpoit oil is what i used.


BUT i was wrong about the the throttle shafts. I took the carbs off again today and checked it. There is some wiggle. I think that may be my problem....

I need to get new throttle shafts and bushings now.

 

thats a late mini on an old log book from what I can see from pics its 1990 to 1993 pre SPi or MPi as for engine size I would sat std 1275 but the only way to tell the cc is by removing the cylinder and measuring the bore dia....is the timing correct are the leads on the dizzy cap in the correct order 1-4-3-2 in anticlockwise order with NO:1 lead at 2o'clock have you got a spark at the plugs fresh fuel and are the air filters clean

 

It has the extra stud on the left end of the engine, and there's a gap between the valve cover and the heater valve, that makes it a big bore engine......either an actual 1275 Cooper S or a 1300 with the extra studs added.....


You can do that on a small block engine, but they don't look the same.....

 

ah yes I missed the extra studs.......could be just a modified head or could be a worked block again need to measurer bores to tell....but the car is a late 1990-93 shell.......

 

The latest copy of MiniWorld mentions a replacement dash with that setup ... they describe it as "the S Works alloy dashboard for the MPi Mini, as an alternative to the walnut veneered dashboard ,,,"

But only matters IF the dash is original to the (very modified) car . . .