thursty mini

[olly_16]

over the last month or so i have noticed i am going to the garage to get petrol virtualy every other day after filling up. i spoke to a mate who said it sounds like it may need more oil in the carb as it using more petrol than takin air, would he be correct and what carb oil would i need to buy?
many thanks

[Gr4H4m]

The dash pot oil needs checking every service about 3k but if you drive hard, you can use more quickly...

There is a lot of talk about what oil(s) to use, and people use loads of different types... some even mix it to their own special formula... as they say they get better throttle response...

I go with a simple method of what ever goes in the enigne should go in the dash pot. You can buy special dash pot oil from Burlen who are the SU carb people.

Anyway this is the list of oil I have come accross people try...

ATF oil
Burlen SU dash pot oil
3 in 1
20W50 - Thats what I use in my twins
10W40
10W40 mixed 50/50 with 3 in 1

As I say it gets all a bit confusing so uncscrew the dsah pot plunger and have a look inside, you will see an inner neck top up to this level with what ever oil you put in your cars engine.

Your car could need a tune up and might be running rich, or have you checked for a fuel leak...

[olly_16]

their is no fuel leak as i have it parked on the drive and their is no spills on the floor and the only time time it leaks is when i put new oil in the engine. i will have a look tommorow on my day off and see. thanks very much for the info mate

[Deano]

How many gallons per mile you doing?:)

[olly_16]

How many gallons per mile you doing?:)

to be totaly honist mate i dont know all as i know is that on a tenners worth of petrol it will get me to shotton and back and be on the red with driving normal

[TONYELF]

You tried pushing choke back in? LOL What colour are the S/Plugs? is it running fast? Shotton and back should have not used any petrol in that distance.
I'm getting at least 40 mpg out of Elle. bog standard 998cc.(no modifications whatsoever-boring!)
On the Aberystwyth run driving at 50-70 (70+ in places, I was only getting about 23 mpg ! I use Three In One oil in my dashpot or engine oil when I have'nt got 3 in 1.
Sounds daft but are back brakes binding? You will have to look at everything before it bankrupts you !

[Gr4H4m]

to be totaly honist mate i dont know all as i know is that on a tenners worth of petrol it will get me to shotton and back and be on the red with driving normal

Holy smoke like The elf says you could run a super car on that.... I would think if it was that rich you would have very dark plugs. you want a light brown colour... the repair would be cheaper that running it at that rate.:eek:

[Steve]

I would say that it has a leak or the the carb is :mad: if I was I would just buy a second hand carb try and go for hif 38 or 44 as they never let you down. If you have no leaks then replacing the carb would be cheaper than using all that petrol.

[olly_16]

yeh the choke is pushed in after driving for a about 2 mins as i find it runs naff when just started but i have also found that when having the choke fully in slowing down/ or stopping for traffic or traffic likes it likes to stall? any reason for this? it does sound like the engine is running fast,its only been since my last MOT when they had lower the mixture of the carb to pass it through the emmissions, it also has a diff carb nedel from when i had it rolling roaded so would it possably be worth getting it set back up again?

[Gr4H4m]

yeh the choke is pushed in after driving for a about 2 mins as i find it runs naff when just started but i have also found that when having the choke fully in slowing down/ or stopping for traffic or traffic likes it likes to stall? any reason for this? it does sound like the engine is running fast,its only been since my last MOT when they had lower the mixture of the carb to pass it through the emmissions, it also has a diff carb nedel from when i had it rolling roaded so would it possably be worth getting it set back up again?

You do need a bit of choke when starting up.. When you are slowing down the damper rate in the dash pot could be wrong I had this once. have you tried to top it up since you post above? it could cause the engine to stall. It might need thicker oil.

The carb needle at the RR would have been changed to get your mixture correct for power if the MOT station has changed the mixture settings you wont be running right but you would of thought lean not rich.. the engine idle is set with a screw and you should be about 750-850 rpm it depends on the engine.
A RR will beable to set the car up correctly.

[olly_16]

You do need a bit of choke when starting up.. When you are slowing down the damper rate in the dash pot could be wrong I had this once. have you tried to top it up since you post above? it could cause the engine to stall. It might need thicker oil.

The carb needle at the RR would have been changed to get your mixture correct for power if the MOT station has changed the mixture settings you wont be running right but you would of thought lean not rich.. the engine idle is set with a screw and you should be about 750-850 rpm it depends on the engine.
A RR will beable to set the car up correctly.

i am going to check the dash pot and i am also going to get it rolling roaded at some point to get it set up right

[olly_16]

i think i may have found the problem i noticed abit of black soot and the inlet slightly burnt aswell. and when rev the enigine blue smoke coming from the manifold

[Gr4H4m]

i think i may have found the problem i noticed abit of black soot and the inlet slightly burnt aswell. and when rev the enigine blue smoke coming from the manifold

manifold leaking needs sorting mate you can get good think gaskets from the quality factor Chester near staples on greyhound

[Steve]

This may be helpfull.

Some later Mini models are equipped with special emission carburettors which have plastic seals fitted at the adjustment points to render them 'tamperproof. The purpose of this is to prevent unqualified persons from making adjustments which could increase emissions above a predetermined level, either through lack of understanding or unsuitable measuring equipment.
These seals must be destroyed in order to gain access to the idle speed screw and/or mixture adjusting nut. The idle speed screw is sealed by a small plastic push-fit plug, and the mixture adjusting nut by a two-piece snap-fit plastic cover. With these carburettors it is advised that no attempt be made to remove the sealing plugs or covers or alter the settings of the sealed adjusters.
On carburettors of the conventional type, without seals, the idle adjustment is carried out in the normal manner.

Damper Oil Level The oil level in the carburettor damper reservoir must be maintained approximately 0.5 in (13 mm) above the top of the hollow piston rod .
To check the level, unscrew the damper cap from the top of the suction chamber and withdraw the cap and damper. Top up if necessary with light oil (preferably SAE 20 grade). Push the damper assembly back into position and screw the cap firmly into place.
Failure to maintain the oil at the correct level will cause the piston to flutter and reduce acceleration.

Slow Running Adjustment Before attempting to adjust the carburettor slow-running setting, ensure that all other items relevant to good engine performance are in good condition and/or correctly adjusted (e.g. contact breaker points, ignition timing, spark plugs, valve clearances, etc.). Also check the air cleaner to ensure that the element is clean, and check that the throttle operation is free and unrestricted.
Carburettor tuning should be confined to setting the idling and fast idling speeds and the mixture at idle speed. A reliable tachometer should be used if possible - make use of the car's tachometer if one is fitted.
On vehicles fitted with emission control equipment, refer to the EMISSION CONTROL SYSTEMS section before attempting to carry out any tuning or servicing operations on the carburettor.
Where a vehicle must conform to exhaust emission control regulations, adjustments should only be carried out if the use of a reliable tachometer and exhaust gas analyzer (CO meter) are available.
1. Check the oil level in the piston damper, as detailed above, and top up if necessary.
2. Check that the throttle moves freely without signs of of sticking and returns fully when released.
3. Check that the mixture control returns fully when the choke cable is pushed fully home. Also check that the cable has about 1/16 in (2 mm) free-play before it starts to pull on the lever.
4. Check that a small clearance exists between the end of the fast idle screw and the fast idle cam.
5. Raise the carburettor piston and check that it falls freely onto the carburettor bridge with a distinct metallic click when released. The piston can be raised for this purpose either with the piston lifting pin at the side of the carburettor, or directly with a finger at the air intake. In this latter case the air cleaner must first be removed to gain access. If the piston fails to fall freely, the jet must be centred as detailed in the FUEL SYSTEM section.
6. Connect a suitable tachometer to the engine, if available.
7. On models with automatic transmission, move the selector into the 'N' position and fully apply the handbrake.
8. Start the engine and run it at fast idle until it has attained its normal running temperature. Continue to run it for a further five minutes.
9. Temporarily increase the engine speed to approximately 2,500 rpm, and maintain this speed for about half a minute to clear the inlet manifold of excess fuel.
Repeat this procedure at three minute intervals if the remainder of the adjustments cannot be completed within this period of time.
10. Check the idle speed and adjust if necessary by turning the throttle adjusting screw. The idle speed should be about 750 - 800 rpm for most later models, or 500 - 650 for models up to 1972. Refer to 'Tune-Up Data' at the end of the section for a list of the precise specified figures, if required.
11. Now adjust the idle mixture by turning the jet adjusting nut one flat at a time, up or down, until the fastest idle speed consistent with smooth running is achieved (Point A on graph in ). Turning the nut up will weaken the mixture, and down will enrich it. Now turn the nut up slowly (weakening) until the engine speed just starts to fall (point B on graph). This should give the weakest position for maximum speed.
12. Recheck the idle speed and adjust if necessary to obtain the specified idle speed.
13. The mixture strength can be checked on lifting the piston approximately 1/32 in (0.8 mm) with the lifting pin.
a) If the engine speed momentarily increases very slightly, the mixture is correct.
b) If the engine speed increases, and continues to do so, the mixture is too rich.
c) If the engine speed decreases, the mixture strength is too weak.
14. When the mixture is correct, the exhaust note should be regular and even. If it is irregular, with a splashy type of misfire and colourless exhaust, the mixture is too weak.
If there is a regular or rhythmical type of misfire in the exhaust beat, together with a blackish exhaust, then the mixture is too rich.
15. On models which must conform to emission control regulations, check that the reading is within the specified limits - normally 3.0 to 4.5% CO - using the exhaust gas analyzer. If the reading falls outside the specified limits, reset the jet adjusting nut by the minimum amount necessary to bring the reading just within the limits. If more than half a turn of the adjusting nut is required, the carburettor should be removed for servicing. 16. To check the fast idle speed, pull out the choke knob until the linkage is just about to move the mixture jet and lock the knob in this position. The fast idle speed should be about 1100 - 1200 rpm, or slightly less for pre '72 models. Again refer to 'Tune-Up Data' for the precise specified figures, if required.
If adjustment is necessary, turn the fast idle screw until the correct fast idle speed is obtained. Push the choke knob fully in and check that a clearance exists between the end of the fast idle screw and the fast idle cam.