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Gary
Member
Posts: 190

It usually runs on for a couple of seconds after I switch it of.

The spec is:

1275 bored out to 1330 (cam unknown)

Facet Red top fuel pump and fuel regulator (uncalibrated as yet).

1.75" SU carb.

Aldon Yellow dizzy.

9 stud standard 12G940 big valve head.

It does not run hot - in fact it runs a bit cool.

The timing is spot on and it does not pink and it pulls like a train from 1500rpm in top.

The head has been decoked, the valves have been reground and new unleaded valve seats have been fitted by Slark Race Engineering - it also ran on before this work

The pistons have also been decoked.

My thinking is it could be over-fueled but with no carbon in the combustion chambers I dont see how it could "fire" with no spark.

Any suggestions?????

--

Got a life ..... Got a Mini ...... Re-living my youth!!

September 1, 2012 at 4:35 PM Flag Quote & Reply

Ricky & Bianca
Member
Posts: 10

In my experience, this usually this happens if the fuel / air mixture is not rich enough (too much air / too little fuel) which causes spots on the cylinder head, pistons, or the block itself that get too hot which means that any unburnt fuel in the cylinders will continue to ignite even after the ignition has been cut. I would suggest to use a colortune to check it. Hope this helps

October 13, 2012 at 12:37 PM Flag Quote & Reply

Gary
Member
Posts: 190

I also thought that it was due to Carbon build up in the cylinders but after the head work it was fully de-coked and all clean and shiny but still ran on. It ran on worse when it was particularly hot but now I have cured the overheating problem it is much better but still persistent. I know the timing is spot on but the mixture may be off. I did read somewhere that a fault in the alternator circuit can, on switch off, result in a reverse current flow which provides power to the ignition circuit.

--

Got a life ..... Got a Mini ...... Re-living my youth!!

October 13, 2012 at 2:07 PM Flag Quote & Reply

Gary
Member
Posts: 190

I will check the mixture with a colourtune by the way. Good plan.

--

Got a life ..... Got a Mini ...... Re-living my youth!!

October 13, 2012 at 2:08 PM Flag Quote & Reply

Ricky & Bianca
Member
Posts: 10

You can test the alternator by disconnecting it and the engine has warmed up and shut the motor off and see if it stills runs on. That will narrow it down hopefully. Let me know how you got on.

October 14, 2012 at 12:19 PM Flag Quote & Reply

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