12 replies to this topic

[HurryUpMiniMetro]

Hi all, I'm having a confusing issue with my mini. To start with it's a 1275cc A+ engine. The issue is that sometimes when coming to a stop or accelerating from idle it seems to cut out and just die with only the battery light showing on my dashboard? Weirdly enough it doesn't shudder or anything it just goes completely silently. The other issue which could be related is when accelerating I feel the acceleration sort of dip before returning to normal? Cheers for any help.

Edited by HurryUpMiniMetro, 26 October 2023 - 01:46 PM.

[DeadSquare]

That sounds as though the piston in the carb might be sticking.

 

Unscrew the big knob on the top of the carb and withdraw the damper.  Take the top off the carb, remove the spring and very carefully lift out the piston.  Invert the piston somewhere suitable and drain the oil.

 

Making sure that you take great care of the needle, clean the piston and the inside of the top with a drop of Fairy liquid and Vim  (while the wife is at the hairdresser).

 

Rinse them, dry them, lightly oil them and very carefully re-assemble them.  Almost fill the top of the carb with light oil and screw the damper back in.

 

If that doesn't work, take the bus.

[HurryUpMiniMetro]

That sounds as though the piston in the carb might be sticking.
 
Unscrew the big knob on the top of the carb and withdraw the damper.  Take the top off the carb, remove the spring and very carefully lift out the piston.  Invert the piston somewhere suitable and drain the oil.
 
Making sure that you take great care of the needle, clean the piston and the inside of the top with a drop of Fairy liquid and Vim  (while the wife is at the hairdresser).
 
Rinse them, dry them, lightly oil them and very carefully re-assemble them.  Almost fill the top of the carb with light oil and screw the damper back in.
 
If that doesn't work, take the bus.

I'll have a look at that, I've already been messing around with the dashpot and checking the needle, piston and etc. Just haven't been brave enough yet to separate the dashpot etc.

[Chris1275gt]

I’d also mark the relative position of the suction chamber in relation to the body and replace it as it was and run your finger up inside the suction chamber to feel for any scoring and remove any with a bit of 2000 grit wet and dry very gently.

[bpirie1000]

I would suggest centering the needle back into the carb. Plenty you tube videos explaining things.


https://youtu.be/bYe...2sJWtAaYlAt6H6s

[cal844]

Personally I can't recommend an AC Dodd optimisation session enough (if in the UK)

I had a local to me (central Scotland) specialist who has AC's training and the session totally transformed the car to the point where it got driven more than it had been

[HurryUpMiniMetro]

Right I've checked the carb but weirdly enough the issue is still there and so intermittent, once again stopped in traffic, pulled handbrake up and then the revs began to drop and the engine stalled. Then again went to accelerate into a roundabout and it kicked like a donkey before cutting out? I've also found that when I rev at idle the revs then drop below idle tickover before returning to normal? And also when accelerating and changing up from 2nd into 3rd the car had a loss of power and bogged down. Super confusing 😕

[cal844]

Carb needs set up, classic signs of lean running

Edited by cal844, 01 November 2023 - 05:47 PM.

[68+86auto]

It does sound like a carb issue (probably just tuning). It could be an issue at all rpms but you only really notice it at idle as it is really the most sensitive area.

[andyapanel]

I had this
The solution was to increase the idle slightly
I have no idea how it reduced the idle speed itself, but that is mini carbs for you.

[Lplus]

I had this
The solution was to increase the idle slightly
I have no idea how it reduced the idle speed itself, but that is mini carbs for you.

The idle speed can reduce if the vacuum advance system stops working and the idle timing retards.

[HurryUpMiniMetro]

Mixture adjusted and a little bit of idle adjustment too and she's sounding and driving good, fingers crossed it is all fine 🤞

[bpirie1000]

Well done and thanks for sharing another problem on a mini fixed...