hey guys,

I'm a new mini owner and just learning my way around mechanical bits so speak slowly

I've just got a 1275GT which has a 1380 engine in it which has been recently rebuilt. I've got the full list of specs if needed. However i'm finding that i can't start the engine with the clutch in (it simply won't turn over) and if i'm stopped at the lights with the clutch in the engine starts to splutter and die. However if the choke is on the dieing at the lights DOESN'T happen. Idle is quite high (~800-1000, tacho not working) but feels very rough. Previous owner had it dyno tuned but since then put a giant Graham Russell inlet manifold without retuning on it so perhaps that has something to do with it ? Slight rattle in the clutch housing which disappears when clutch is engaged. Clutch has been completely rebuilt with 4 pin diff and all that jazz < 2000km ago.

Any ideas ? i've got it booked in with the local mini mechanic but thats not for 2 weeks and she looks forlorn sitting there not being driven

Couple of random-ish thoughts from me:

Why are you trying to start the car in anything other than neutral (with your foot nowhere near the clutch)?

Anyway, that aside, sounds like the clutch is not engaging fully - i.e. drive is not being disengaged entirely (I've spelt that out because some people get all pedantic about clutch terminology!). Unfortunately this can be for a variety of reasons, either mechanical or hydraulic. If it's never worked since the rebuild, I'd say mechanically not set up correctly. If used to work but now doesn't, I'd say hydraulic system wear (which can also mean mechanical wear!).

The rattle that goes away when clutch pressed is the throw out bearing.

These two things together make me think the whole drive/clutch arrangement has not been sorted properly at the rebuild. Or was sorted, but not by somebody who knew what they were doing!

Thrust bearing if it dies when car in neutral

If in gear when it dies check clutch adjustment

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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

I've seen a similar issue with two cars recently (one of them being mine )

In both cases it was due to at least one of the thrust washers being installed backwards. Easy to do but a pain in the arse to fix.

[quote="smac"]Couple of random-ish thoughts from me:

Why are you trying to start the car in anything other than neutral (with your foot nowhere near the clutch)?

it was more for differential diagnosis than anything else. shouldn't the car be able to start with the clutch in ?

Yes, but as above your clutch is not completely disengaging - it's like you're only putting your foot down half way, so what you're actually doing is trying to start the car partially in gear.

thanks for all your quick answers guys any idea why having the choke on would prevent the stalling ?

With the choke on, do the revs drop at all when you de-clutch?

not that i notice, tacho doesn't work due to the megajolt system installed so thats only by ear

I would imagine it's because of the idle raising function associated with the choke, not the mixture difference. Try adding a little throttle instead of choke, should have same effect. The added revs are overcoming the dragging clutch.

Before driving anywhere else, check your clutch!

Do you have the "overthrow" nuts on the end of the clutch bearing carrier? If the clutch is allowed to travel too far it puts excessive pressure on the crank thrusts, wearing them out - fast!!

When you press the clutch is there a noticeable drop in revs? If so the most likely cause is clutch overthrow.

If the revs don't change but it still stalls then it's another reason. Does it crunch in any gears?

cheers,

_________________
'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

hate to say it but low'n blown is correct.

Whoever built the engine put the thurst washers round the wrong way, or failing that have put the incorrect size in.

The choke is just lifting the revs like more idle will, so that's why it helps. I wouldn't drive the car very far, if you can help it NOT AT ALL!!

I've seen the effects of this...

Easy way to tell is up the idle a bit, so it idles ok with clutch in and out.. it will be high tho dont worry about that..

Then get someone to put the clutch in at idle and you stick your head in the engine bay and watch the harmonic blancer move sideways towards the radiator.. It's only maybe 5mm or so slightly, but you will see it if you look good enough as it's travelling at speed.. it's pushing the whole crank sideways in other words...

That also explains the rattle noise when clutch is out..

Engine pull down and replace thrust bearings, and hope that the crank has not been worn from the driving..

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Bluey-1973 Clubby - 1330, high lift, big cam, 7 port madness in progress..

Gumby-1978 Minivan, British Racing Green - 1310, high lift, mild cam, enlarged porting and chamber shape with big valve head, supercharged build in ever slow progress!

don't jump to the conclusion that it's the thrusts in backwards...

first thing to do is adjust the clutch a bit and see if it goes away - there's a little 7/16 bolt on the clutch housing, undo that a couple of turns and see if it's better

tru..

Just everything that is described is EXACTLY how one of my engines were... the rattle,,, the stalling,, the revs etc..

As soon as you look at the harmonic blancer when running with and without the clutch you will be able to tell straight away.. nice easy way to diagnose it..

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Bluey-1973 Clubby - 1330, high lift, big cam, 7 port madness in progress..

Gumby-1978 Minivan, British Racing Green - 1310, high lift, mild cam, enlarged porting and chamber shape with big valve head, supercharged build in ever slow progress!

thanks guys. i won't drive it anymore until i can get it fixed. Already driven it back 600km from where i bought it so hopefully its not farked :/