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 Posted: Jul 30, 2018 07:27AM
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CA
Ahhhh... we all overlooked the over-run valve!

.

"Hang on a minute lads....I've got a great idea."

 Posted: Jul 30, 2018 06:44AM
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Just a quick update on the idling issue.

No vacuum leaks that I could find, but I did suspect too much mixture getting by the throttle disc.

I did a couple of things over the weekend:

First, since the throat of the carb was pretty pitted around where the disc seats, I put down a thin layer of JB Weld and worked it with some small files and sand paper until I got a good seal.  I also took a spare disc and removed and soldered over the over-run valve and the small top hole on the disc - effectively creating a solid disc.  With the reduced flow, I now have a nice even idle within spec.  We'll see if this results in any drivability issues but so far none.

It runs a bit lean though mid rpm still, so will look at swapping out the ADD needle for something better suited to the car.

1976 1000 (Current Project)

1975 1000 Donor

1969 Cooper (Future Project)

1971 Opel GT

1972 Corvette Stingray

 Posted: Jul 23, 2018 04:58AM
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Check that the butterfly is centered and closes completely with the idle screw backed off.

If in doubt, flat out. Colin Mc Rae MBE 1968-2007.

Give a car more power and it goes faster on the straights,
make a car lighter and it's faster everywhere. Colin Chapman.

 Posted: Jul 23, 2018 04:42AM
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you may have a vacuum leak.

 Posted: Jul 23, 2018 02:25AM
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CA
Did you loosen the throttle cable before trying to adjust the idle speed? There should be a very wee bit of slack with the throttle completely closed. Check also that the trotted cable is free-running - the gas pedal should drop to the floor if you undo the cable completely. It may be binding somewhere or damaged.

.

"Hang on a minute lads....I've got a great idea."

 Posted: Jul 22, 2018 09:24PM
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croc - It's an HS4.  It's in good working order, freshly rebuilt.  The fast idle screw is also not even on the cam.  I'm expecting to have to fiddle with it since it's set up for an emissions car, but pretty much all the smog equipment was disconnected or gone when I got the car.

I've got an air/fuel setup due to arrive tomorrow and once I get that in I'll know better where I stand with it.  I will likely need a different needle and settings.  Other than the idle, it seems to be running well.

1976 1000 (Current Project)

1975 1000 Donor

1969 Cooper (Future Project)

1971 Opel GT

1972 Corvette Stingray

 Posted: Jul 22, 2018 08:23PM
 Edited:  Jul 22, 2018 08:29PM
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US
HIF44 carb?  Fast idle adjustment correct?

 Posted: Jul 22, 2018 11:44AM
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So......

Having tried just about all I can think of this morning I took the pedal out to see if I could remove the 1 mm of slop at the MC piston fork..  Spent a few hours welding up the hole and re-drilling it perfectly round and putting in a new pin.  1 mm of slop pretty much gone.

After a few hits and misses with different settings I disassembled everything and started from square one.  0.5 mm gap on return bolt, I had my wife hold the clutch in while I set the stop at just meeting the  housing plus one flat.

She starts it up and it goes into all gears including reverse with no issues.  Woohoo!.

We get ready to go for a drive but wait....I have to put the return spring back on the slave cylinder.

Done, now car won't go into any gear!

Took the spring off and went for a nice drive.  When I got back I put a throttle return spring on it since the brand new ridiculously strong slave cylinder spring seems to have been the issue, or at least part of it.

Now onto figuring out why it won't idle less than 1,400 rpm even with the idle screw all the way out.  More to come on that..

1976 1000 (Current Project)

1975 1000 Donor

1969 Cooper (Future Project)

1971 Opel GT

1972 Corvette Stingray

 Posted: Jul 21, 2018 08:43AM
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Thanks for all the input.  My clutch arm is in good shape, no wear on the ball.  It sound like some minor fiddling with the various components is the first step.  I've read a lot of good and bad about the adjustable slave cylinder rod.  I seem to have decent travel on the arm itself, 5/8" or so.  I'll try a few things this week and see what I can end up with.

1976 1000 (Current Project)

1975 1000 Donor

1969 Cooper (Future Project)

1971 Opel GT

1972 Corvette Stingray

 Posted: Jul 21, 2018 12:23AM
 Edited:  Jul 21, 2018 12:26AM
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Even easier.... wind the overthrow stop bolts (the ones on the end of the release bearing carrier) back about 1/2 an inch (or remover them altogether).  Remove the clutch lever return spring.  Wind the return stop bolt (the one on the wok about half way up the clutch arm) well clear of the lever.. 

Peel back the boot at the end of slave cylinder so that you can see the slave piston.  Have attractive assistant press clutch pedal to floor while you watch the slave piston.    Does the piston touch the C clip retainer at the outer end of the slave bore?  if yes THEN you need a longer push rod, if no then a longer rod will buy you nothing.

You didn't mention renewing the clutch lever/release bearing carrier? If the slave piston is not restricted by the C clip then a new lever/carrier won't buy you anything either.  If it is, then a new lever/carrier may improve things .... a bit.

Try a drive (don't touch the overthrow nuts/don't replace the slave spring) ..is the problem solved?  

If not, you might buy a small improvement by allowing a bit more pedal travel by removing/thinning the carpet between the depressed pedal and the firewall.

If you've removed all the slack/wear (3 pins AND the holes they ride in, clutch arm ball AND the hole in the carrier it presses on), made sure that travel is not restricted by the overthrow nuts or the slave C clip, minimised the carpet under the pedal then things get bit more complex if you want more travel.  

Options include a larger master bore, smaller slave cyl bore or a longer clutch arm (unfortunately the slave to arm pushrod doesn't have anything to contribute at this stage).

As for question 2.... for your problem.... no.  Having the straps parallel is not the required outcome; you need to have the diaphragm spring "flat".  This is a good idea as this will reduce pedal pressure and make the clutch more effective.

Cheers, Ian

 Posted: Jul 20, 2018 03:09PM
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US
Make it easy and no need to buy anything.
It's been quite a while since I've had any clutch renewal work at 0.20" on the return stop. The accuracy of the parts just ain't like the olde days.
If you're pedal is too close to the floor simply move the return stop bolt out more. Start with 3 to 6 flats. Just don't move the bolt out too far causing the throw out bearing to ride on the clutch spring all the time. I had to go three full turns on one car, but almost all get working correctly before 12 flats.
All the above assumes all the clutch parts are assembled correctly and that the clutch master and slave are bled well.

 Posted: Jul 20, 2018 11:23AM
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US
Absolutely, adding an adjustable push rod allows "tuning" the pedal for desired engagement. Just don't over do it.  You must release the load on the throw out bearing when not on the pedal,  and must not try to drive the slave piston past the end of it's travel.  There is plenty of range to get it right if the supporting parts are good.

 Posted: Jul 20, 2018 08:26AM
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Have you replaced the clutch arm? The ball on the end wears out on the contact side, some owners bend the arm to get more adjustment and others use adjustable slave rods or put a nut on the end to improve the clutch engagement point.

I believe it is Cooper Tune/Steve who  notches his clutch or brake pedals then re welds them to get them the same height.

If in doubt, flat out. Colin Mc Rae MBE 1968-2007.

Give a car more power and it goes faster on the straights,
make a car lighter and it's faster everywhere. Colin Chapman.

 Posted: Jul 20, 2018 08:23AM
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I have been completely defeated by this issue, in the end I think my left rear wheel is a little too far back to get proper clutch adjustment. I resorted to an adjustable pushrod for slave to clutch arm, only needed about a 1/8" extra to position the pedal right in the middle of travel, no more gear grinding, works a treat in my case. Others will disagree/agree. Good luck 

 Posted: Jul 20, 2018 07:53AM
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Looking for a little sage advice.  I have searched this site, and others, and understand the ins and outs of the pre-verto clutch adjustment, but I'm still not happy with the clutch height and engagement point of the pedal.  Clutch engages just above the floor and while I can get into the forward gears, reverse tend to grind.

The car has a new master cylinder, slave cylinder, rubber hose, TO bearing, disc and diaphram.  Basically all new.  There is no slop or wear in any of the usual points of concern.  The MC has been bled and has no air.

I've set the return stop to .020 and adjusted the other nuts to 1/8" travel per some suggestions.  Setting it per the manual gave worse results.

1.  what else can be done to raise the pedal height short of bending the pedal?  Reduce the thickness of the bulkhead gasket?
2.  Also I am curious on the impact of the friction plate straps.  I did notice that mine are not parallel to the flywheel.  Can anyone tell me for certain whether adding spacers under the attachment bolts to correct this would impact the engagement?  

1976 1000 (Current Project)

1975 1000 Donor

1969 Cooper (Future Project)

1971 Opel GT

1972 Corvette Stingray