I think I already know what the problem is but I would like some opinions from the 'knowledgeable'

Symptoms - running very rough, needs choke to start, no power (only up a gentle hill if in first), will not respond to throttle, slowly builds up revs after a 5-10 second delay, plugs on 1 and 4 look good but 2 is 'sooty' and 3 is black and slightly moist.

I haven't done a compression test yet (I need a gauge) and when I rebuilt the HS4 yesterday apart from being badly 'bodged' when last assembled it also had a fair bit of black (carbon??) in the throat on the engine side of the butterfly.

So what do we think?

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"Never attribute to malice that which can be adequately explained by stupidity!"
1972 Mini Clubman 1098
1978 Leyland Mini 998 - she’s gone to a good home

head gasket

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did I tell you that I won a trophy?

Rocker clearances too tight?

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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.

condensor

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Timing way out.... backfiring?

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The best part of fixing your mini is the test drive

Minis..

1976 van daily drive
1975 van
1968 deluxe in the shed
1967 deluxe high strung 1310
1959 austin healey sprite

Vacuum pipe to dissy fall off?
Sucking air?

Points closed up?

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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.

Whoa....that's a broad range....and he's me thinking burnt exhaust valves

In addition I should have mentioned that it is running what look to be almost new NGK BP5ES plugs, the vacuum advance on the carby is blanked and also removed from the dizzy. It only backfires on decel. This Mini is new to me and has been sitting with almost no use for about 6 months at least. I have almost no history of the mechanics of the car because the young fella I bought it from had no mechanical back ground and didn't ask.

I also suspect the fuel may be contaminated so that's coming out next and the tank and lines cleaned....and then that compression test.

Oh and thanks for all the suggestions thus far

_________________
"Never attribute to malice that which can be adequately explained by stupidity!"
1972 Mini Clubman 1098
1978 Leyland Mini 998 - she’s gone to a good home

Bad fuel will give you all your symtoms..

_________________
The best part of fixing your mini is the test drive

Minis..

1976 van daily drive
1975 van
1968 deluxe in the shed
1967 deluxe high strung 1310
1959 austin healey sprite

Its probably the battery Son

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1970 Cooper S ex-Bathurst & ATCC
1964 Austin Cooper S ex-Group C race car
1967 Morris Cooper S ex-Group B
1962 Mini Speed sports sedan
1968-71 ex-Peter Manton Shell car

Where's that Dad?

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"Show me the Mini!"

In the boot son.

I know the exact problem, there's something wrong with the motor thingo under the front cover bit.

Seriously though Id start with comp test before jumping to any conclusions, it might be something else but given your description it sounds like surgery.

R the plug leads on right

It helps if you put your location in , there maybe someone close by that could lend you a compression gauge.

Bloody hell....nobody's called me 'son' in the last decade

I'll update my details but for what it's worth I'm in Albany (West Oz)

My thoughts were 'surgery' too....but I'll go through the basics first (firing order, ignition parts, dizzy which looks really rough, compression test, etc)

We'll get there in the end

_________________
"Never attribute to malice that which can be adequately explained by stupidity!"
1972 Mini Clubman 1098
1978 Leyland Mini 998 - she’s gone to a good home