Classic Mini - Help diagnose my problems!
Discussion
pat_y said:
Mini_Lund said:
pat_y said:
Bit left field but dont suppose you could have a blocked exhaust (collasped silencer), this will make it run like a total bucket guaranteed.
Its a straight through system rc40, less than 6 months old, I think its fine 
freddytin said:
OK , remove the oil filler cap, pull the breather tube off at the carb end, then blow into the breather as hard as you can. You should be able to hear air coming out of the rocker cover, if not the breather is blocked.
I can hear air through the breather, nice and easy to push air through. Im unsure if my carburettor is adjusted properly, as mentioned before the piston moves up and down freely, but if I push it up too far it sticks at the top and doesnt fall down. lubricate the hollow shaft it slides on? Unsure if the mixture is set correctly, I know its an 850, but I seem to have a lack of power when i need it the most... what should I adjust?
I have also noticed that there is no difference between the choke all the way in and the choke half-way out. Although the idle speed seems normal to me.
Thanks once again, all of you helping me at PH!
Edited by Mini_Lund on Friday 9th May 17:21
Edited by Mini_Lund on Friday 9th May 17:24
In the 'dashpot' (top of the carb), the hollow tube will lubricate itself as oil 'spills' from the inside of the hollow tube and down its outside. So that looks after itself .
Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it .
Nice looking Mini btw - and it has a registration number local to me.
.Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it
.Nice looking Mini btw - and it has a registration number local to me.
aw51 121565 said:
In the 'dashpot' (top of the carb), the hollow tube will lubricate itself as oil 'spills' from the inside of the hollow tube and down its outside. So that looks after itself .
Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it .
Nice looking Mini btw - and it has a registration number local to me.
Yehr cleaned it all, the whole carb was cleaned in petrol. The carb on the car is the original carb, the head is also the original head. Its basically untouched...until recently .Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it
.Nice looking Mini btw - and it has a registration number local to me.
Since it was the last of the 850's produced by British Leyland, it has a HS4 carb and a Cam 4810 head. (998 head)What area is the plate from?
Edited by Mini_Lund on Friday 9th May 18:03
if you need to adjust the mixture of the fuel jet in the carb- at the bottom of the carb you'll see a nut maybe two with a small pipe going to it, this is a tube/jet that the dash pot needle goes up and down in.
to make it richier you need to lengthen the jet by undoing the lock nut then thighten the other nut up more so you get more thread showing.
to make it leaner slacken the nut off and push the jet further into the carb then when your happy thighten both the nuts up so it locks it together and stops it moving.
if you can't move the jet freely in the carb it will need replacing.
also burning oil and other head issues will make it run rough also running on unleaded fuel will burn the valve seats out unless harder ones have been fitted.
and when running unleaded the timing needs to be retarded a bit to stop it pinking.
to make it richier you need to lengthen the jet by undoing the lock nut then thighten the other nut up more so you get more thread showing.
to make it leaner slacken the nut off and push the jet further into the carb then when your happy thighten both the nuts up so it locks it together and stops it moving.
if you can't move the jet freely in the carb it will need replacing.
also burning oil and other head issues will make it run rough also running on unleaded fuel will burn the valve seats out unless harder ones have been fitted.
and when running unleaded the timing needs to be retarded a bit to stop it pinking.
Well, you've had every possible problem suggested short of Martians landing! Most are improbable.
best thing you can do is to find some village garage where the owner is old and grizzled (ie has worked onj something other than Jap and Frog boxes) and ask him to look at the car.
The commonest problem with lucas ignition is the points closing up as the heel wears causing misfires. However, that wouldnt cause oil smoke from the exhaust. The only thing that would do that is a worn engine, but you'll only find which bit when you take it to bits. Dont worry - BL engines are cheap to work on and quite simple
best thing you can do is to find some village garage where the owner is old and grizzled (ie has worked onj something other than Jap and Frog boxes) and ask him to look at the car.
The commonest problem with lucas ignition is the points closing up as the heel wears causing misfires. However, that wouldnt cause oil smoke from the exhaust. The only thing that would do that is a worn engine, but you'll only find which bit when you take it to bits. Dont worry - BL engines are cheap to work on and quite simple
Mini_Lund said:
Thanks for all of the feedback.
Plugs look normal colour, quite black but with copper deposits.
Plugs shouldn't be black, thats a sign of running rich, very rich!the plugs should be a nice light grey/beige sort of colour.Plugs look normal colour, quite black but with copper deposits.
If you've had the carb in pieces and then rebuilt it with a few new parts then it will need to be completely set up again. From memory this will include setting the jet height and the mixture.
you mention there's not much difference when the chokes out, that could because she's running very rich already.
Don't forget if you've had the carb off you'll need to set the idle speed, and the fast idle (the one that makes the engine rev when you pull the choke out).
Get a copy (if you've not already got one) of the light blue haynes book , this should give you plenty of info on the rebuild of the carb, and the setting up of it afterwards.
Ultimately, once you've got the car running acceptably, the only way it'll ever be spot on is to have a rolling road tune, and for that i'd put the electronic ignition back in, as its a truely fit and forget bit of kit, and far more tolerant of dampness etc than a set of points.
freddytin said:
Looks like you're better at checking your e mail than me. 
Its one of the tabs I keep open in firefox; you'd be surprised at how many emails I've had off PH members. Really good to know I'm well looked after at the tender age of 18. I have a vast knowledge of Mini's but still learning, gaining much experience! I'm more hot on Land Rovers to be honest with you, but there has it! ooo just received an email from Tesco... 
Mini_Lund said:
aw51 121565 said:
In the 'dashpot' (top of the carb), the hollow tube will lubricate itself as oil 'spills' from the inside of the hollow tube and down its outside. So that looks after itself .
Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it .
Nice looking Mini btw - and it has a registration number local to me.
Yehr cleaned it all, the whole carb was cleaned in petrol. The carb on the car is the original carb, the head is also the original head. Its basically untouched...until recently .Have you had the dashpot apart and cleaned everything (I mean everything, including the inside of the chamber and outside of the piston) up inside there with white spirit and kitchen paper? It often makes a difference to a poorly running car as a lot of 'sticky crud' can build up and cause the piston to stick.
But don't use any kind of polish, as that messes up the clearances between the piston and chamber and the carb will never ever work again...
Failing this, when did the problem start? Does it go as far back as when you swapped carbs (presuming I am reading that the engine has a non-original carb)? If this last is irrelevant, ignore it
.Nice looking Mini btw - and it has a registration number local to me.
Since it was the last of the 850's produced by British Leyland, it has a HS4 carb and a Cam 4810 head. (998 head)What area is the plate from?
Edited by Mini_Lund on Friday 9th May 18:03
. The car was first registered in Bolton.
Incidentally, what unleaded fuel additive are you using? If the head is original and untouched, then the addition of the recommended amount of one of these to the tank is essential every petrol stop for a pre-89 Mini - the exhaust valve seats won't last long on an A-series engine driven with any kind of verve, and cause loss of compression and (generally) bad running and economy (if the head has been off and hardened valve seats have been fitted, ignore this).
Simple one I know & you've probably checked it already, but are the HT leads on in the correct order.
Firing order is 1342 if my memory serves me....
Is the lead from the coil - dizzy in good order too?
To me your misfire/rough running sounds like it's more an electrical one than mechanical check all connections - including earth straps on the battery and also the engine - usually located on the engine stabiliser to the bulk head - also check all connections on the solenoid and that this is bolted tight to the body (ie:earthed) - usually located o/s inner wing above the clutch housing.
However, it could be fueling too, is your float chamber operating correctly and free from any contamination - dirty petrol in the jet.
When you dismantled the carb did you make sure you put everything back as it was re: carb needle, dashpot spring etc. If you left the spring out of the carb the piston will rise too quickly causing overfueling (too rich).
HTH.
Firing order is 1342 if my memory serves me....
Is the lead from the coil - dizzy in good order too?
To me your misfire/rough running sounds like it's more an electrical one than mechanical check all connections - including earth straps on the battery and also the engine - usually located on the engine stabiliser to the bulk head - also check all connections on the solenoid and that this is bolted tight to the body (ie:earthed) - usually located o/s inner wing above the clutch housing.
However, it could be fueling too, is your float chamber operating correctly and free from any contamination - dirty petrol in the jet.
When you dismantled the carb did you make sure you put everything back as it was re: carb needle, dashpot spring etc. If you left the spring out of the carb the piston will rise too quickly causing overfueling (too rich).
HTH.
my guess is it just needs setting up from stratch rather than messing with different bits at different times. The head gasket could be the issue as they have a habit of popping between 2 and 3, this is normally on bigger a series engines though not 850's. I would say an HS4 is too big for an 850. I would also guess the needle has not been centralized, hence the sticky piston. I would also guess that the butterfly spindle bushes are past there best. ignition parts could also be the issue, they are often very poorly made. the wire from the coil to the points should also be carefully checked as they can break causing missfire when the the dizzy autoadvances.
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