car bubbling a bit/running rough ..

[xpress]

hi there, trying to get things right as a sort of pre mot check. the car feels a bit bubbly with full throttle, but idles well and at low/decent revs. just when the throttle is a bit more open, seems a bit "airy".

can you put to me what this could be and how to correct it?

i do remember the guy selling it saying that you correct for unleaded fuel with a leaded head by advancing the timing a bit, but a guy today said that the timing sounded a bit too fast, but how can you check the timing by just listening to it? or did he mean the mixture maybe/the idle?

he did say you can get this thing that goes from the king ht lead to the king distributor plug and it helps prolong the spark a bit because he said he used to have one and said the spark was a bit quick on them and needed to be a little bit longer. does this sound right to you? i would have though the spark could have been made a bit longer by changing the gap of the plugs?

i need to get a distributor cap for a moggie do you think gsf would have them and plugs best ones for moggies?

ALSO can someone explain to an idiot like me how to check the timing is right/and where is the mixture idle screws etc? i have the following ..

a multimeter with inductive pickup to check rpm - correct values should be?

a co2 tester - (a big hawk one that looks like it's from the 70s/80s). - can someone tell me in idiot language how to check with it?

or can i check it by ear, the pinking method etc. to adjust until it's running right?

i have a gunson timing gun too and can check timing but i would have to find the mark on the flyweel etc, could someone explain this to me or the bmc way of doing it by ear?

i am pretty good with sound so the doing it by ear might work!

[aupickup]

adjust by advancing and pinking under load up a hill and then retard until the pinking stops

[MarkyB]

timing sounded a bit too fast

Timing can be advanced, retarded or just right.
The tick-over might be fast or slow.
My understanding is the the timing should be retarded slightly to run unleaded.
"Bubbly" and "airy" are not a terms I've ever heard of in relation to an engine, try describing it with more than one word.

Minors don't get checked for emissions anyway so just check all the lights work and see what the MOT man says.

[xpress]

i thought they don't get checked for emissions!

ok here goes, my description of the engine .. poetry. prose ..

"the engine thus so far in my life here uponeth this eart.

a beautiful thing to see

a pumping squirting heaving mass of beauty

that brings great joy to me".

ahem .. ok it sounds a bit flappy, airy, too much air, or like there's a blown exhaust, not complete push, not complete combustion, not burning correctly.

i am going to get a new diz cap and plugs next. where's the mixture control/do you move the centre screw and move the diz a bit, i hear that timing lights are no good, best to do it by the pinking method.

what's pinking? heading towards stalling?

"thank yee. i will be the idiot with the white miner at the meet".

[linearaudio]

Pinking is a nasty light rattly/sizzly noise as you accelerate hard in the low to mid range. Just because it tends to dissapear as you get towards the top end doesn't make it acceptable unless you want nastinesses to occur to the internal combustion process!
May be running rich, possibly a dirty air filter, that would give uneven running note! Over weak tends to show as a slowing of engine towards the top end, backing off the throttle regains momentum.

[MarkyB]

I wasn't having a go, it's really hard to describe the noises and feelings you get about the engine, but to communicate it with other people you need to use concrete terms like missing, or maybe running out of steam.
I'd suggest taking the plugs out and seeing what colour they are, this gives a good indication of what the petrol mixture is.
I'd describe pinking as a kind of tinkly rattle that doesn't sound serious but actually is .
As I said before the Minor doesn't get tested for emmisions beyond visible smoke, so if it's OK apart from not running so great, try it on for an MOT.
Plenty of people here to help you getting it running right.

[bmcecosse]

Get the MOT before you worry about anything else........ And forget all about 'making the spark longer' etc - never heard such rubbish in all my days! Once you have MOT and can take it out for a decent run - that's when to start worrying about timing and mixture.