I was wondering, a mini with a side draft carb has some problems to start using the starter engine when cold and significantly even more when hot - but since it starts fine in a rolling start (without using the starter) the carb cant be the one to blame and it has to be the electrical system, right? I mean if the carb was off then it wouldnt start in a rolling start either?

Battery loosing its umph? All its available capacity is being used to turn the motor and little left over to generate a fat enough spark. Or the coil maybe dieing or the plugs need cleaning or leads replacing or the points resetting or...

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Don't pump the throttle when hot, if using a Weber or Dellorto! A pump or 2 is OK when cold, but it's real easy to flood the motor when hot. Just crack the throttle & turn the key..

(OTOH, an SU doesn't have an accelerator pump so makes no difference. Pumping one of these does SFA).

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

you could have rust or other chit on the termanals so at crank over the voltage is droping to much to give enuff spark to start
makka

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Anonymous moderation means the agro that is built up towards the mods isn't aimed at an individual (fewer "Makk" attacks). Less stress for mods means less moderator "retirements".

Seems like Kevin is spot on the ball, I was actually wondering whether to pump the throttle when hot. I might also reduce the pump stroke tonight.

Thanks doc you are a legend.

Before you play with pump stroke, measure how much thread is sticking past the nuts and write it down in case you wanna go back.....
To reduce effective pump stroke you undo the nuts back towards end of rod, not tighten- watch it or you will get a flat spot...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Yea I've changed it 3 times before (when cleaning the carb and since just to see how it goes) considering it had 30 chokes in there before the original setting shouldnt really be relevant to my car, should it?

What is the real problem? Does it stumble when you open the throttle? Vizard reckons you need more pump stroke on a siamese ported engine, because therre's 2 cyls sucking on the port (unevenly).
What pump jets are it it- that affects it too.

BTW none of this should affect starting....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Well I only have Vizards old book and he gives pretty minimal instructions there. My idea when servicing the carb was that here's a single carb instead of two - siamese port as you said so it'll need a bigger stroke (especialy since I replaced the 30 chokes with 34s). so i increased the stroke somewhat. I reduced it a bit since with no obvious adverse effect and thinking of reducing it again. It doesnt affect starting but wouldnt it reduce the chance of fluding the engine (coz less petrol is pumped when the accelerator is pressed with the engine off)?

Well I only have Vizards old book and he gives pretty minimal instructions there. My idea when servicing the carb was that here's a single carb instead of two - siamese port as you said so it'll need a bigger stroke (especialy since I replaced the 30 chokes with 34s). so i increased the stroke somewhat. I reduced it a bit since with no obvious adverse effect and thinking of reducing it again. It doesnt affect starting but wouldnt it reduce the chance of fluding the engine (coz less petrol is pumped when the accelerator is pressed with the engine off)?

And yea sorry it does stumble, refuses to turn over on the first attempt and in general requires a fair bit of care to start from cold or hot. Oh and sometimes blows a whiff white smoke into the cabin on an usuccesful attempt.

If it refuses to turn over on 1st attempt, the dizzy is probably advanced a little too much.
Mine was like that- it broke 4 starter pinions until I put a kill switch on the 12V+ wire to the coil...
Since I put a Pulsar dizzy in, it doesn't do that.

Practice starting it without pumping the throttle... it really doesn't need it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Well I've got the manual pulsar dizzy, but the timing does feels off a tiny bit at times, I might ask Ivan to go over it with the light next time I'm over castle hill way.