Bi-metal spring advice

[lanciamad]

I'm putting the Carb back together on a 1600 Beta HPE, and just need some advise on how the bi-metal spring inside the thermostat housing attaches to the automatic choke mechanism
See pics: http://www.flickr.com/photos/lanciamad/sets/72157618547367271/

[hutch6610]

First off you should have a nylon spacer that covers the mechanism in place first - you know that already.

Turn the metallic strip housing through 90 degrees anti clock wise, put the end of the loop (90 degree bend at the bottom in your photo) between the two prongs on the choke mechanism and hold the housing against the carb.
Refit the retaining ring with the three 7mm bolts (slotted to take a screwdriver if still original) just tightening up enough to hold everything in place.

Last, rotate the bi metallic strip housing clock wise - until the mark on it lines up with the mark on the choke mechanism housing (both visible in your photos)
Then tighten up the three screws  - done!

That's factory setting.

If you want the choke to release (come off earlier) turn the housing so the line is about 1 mm to 2 mm to the left  - just experiment until you find what suits your car best.

[lanciamad]

Thanks for the info. hutch
Have done as you say, http://www.flickr.com/photos/lanciamad/3555439703/in/set-72157618547367271/ but there seems to be too much resistance on the choke flap? Holding it fully open. At cold, the engine was around the 650rpm mark before dieing.
I've got it in this sort of position at the moment http://www.flickr.com/photos/lanciamad/3555440115/in/set-72157618547367271/ and seems to start and run better, but of course the engine was a bit warmer by then.
What kind of position and resistance should the choke flap be in  Hope that makes sense'ish i don't know much about carbs.

[rossocorsa]

you might be better off to consider a manual choke conversion,just a thought!

[hutch6610]

Sorry lanciamad made a mistake - spent more time checking spelling ..... what a dope!
What you say makes complete sense.

Once engaged (as you have it now) rotate it fully anti-clock wise until the marks line up on the top - cant apologise enough for that.

Choke flap should be fully closed on engagement when the throttle is applied with quite a bit of resistance - you will be surprised.
Just pop the two water pipes off and rotate it as i said, do this with the engine cold of course.

So now if you want it to come off a little earlier you align the mark to the right by a few millimetres - relieves the spring pressure thus releasing it earlier.

When the engine starts, the choke diaphragm opens the choke flap a little so it does not flood the engine - rev it you will see it open a little.

Auto chokes are very reliable when set up properly (and of course when people who give advise tell you to set it up right!) only
really go wrong if the linkages seize up with rust or when the screws inside come loose - quite a few do - or when the twenty plus year old diaphragm perishes.

Manual choke ....... naaah 

[lanciamad]

Did as you said.... but still didn't have any luck. Had a look at the spare thermostat housing and the end of the spring (End of the loop) was in a different position to the one i was fitting.
Whether it had lost resistance with age or me fiddling with it i don't know.
Have fitted the spare one now, lining the mark up with the other mark, and fingers crossed its fine now. Seems to start up fine, idle is around 1500rpm mark when cold, once warm (needle just showing in the green) dies down to about 950rpm with a blip of the throttle.
Does this sound about right The final test will be when it gets a good run out and gets hot. But I let the fan cut in and out a few times and seemed fine so far.

[hutch6610]

No you did not do any damage to it, its a spring after all!
Sounds like the spring had come away from the housing (i have had quite a few) and somebody put it back in the wrong orientation - i was going to ask if it looks like it has been tampered with in the middle (its just crimped to hold it to the housing) but didn't bother ... why make things more complicated?

Fast idle at 1500 is pretty much spot on and comes off with a blip is spot on again - you are a master carb builder! remember during the winter the fast idle will be a bit slower.

That's exactly how it should work, its a stepped cam after all and to engage from cold you have to press the pedal, when running (driving) will come off on its own.

Good work.

[lanciamad]

Well, the car was taken for a run today, and things didn't start brilliantly car had been running fine for me ever since i fitted the new thermostat housing, my dad gets in the car, turn it on and will it idle; no. Whipped the air cleaner housing top off, held the auto choke closed, then once started it engaged as it should have and was fine in that respect. Out with the WD40 i'm thinking.
After 40 mins of the journey the car was now really hot, and warmed up nicely, and is now cutting out when dropping revs, such as under braking with clutch in. The best it will achieve of keep going at an "idle" is around the 600-650 rpm mark. Is this down to the mixture becoming too lean when fully warmed up Next question is, what do i need to do to get the idle up nearer the 1000rpm mark
Now i'm starting to think all that work on my IE's been worth it

[hutch6610]

Sounds like you have a blocked or partially blocked idle jet.
Its not getting enough fuel through the jet.

Of the four jets you see in the middle of the carb with the air cleaner cover off its the slotted screw head furthest away.
Undo it and take it out - you need tweezers or long nosed pliers - blow out with compressed air if you have a compressor, thats both the jet and the carb.
Blow down the carb carefully as fuel will spray everywhere.

If not remove the jet from the threaded holder and look through it to see if its clear, blow it through with your mouth (my method) or if you don't fancy doing it that way use your WD40 can and with the straw blast it through then put it back together, pop it back in the carb tightening it until it just seats - don't tighten fully yet.

Run the engine, with your right hand hold the revs around 3000 rpm and with your left unscrew the jet about half a turn and then re tighten it up - point of this is to flush any debris left through ... try it it works.

If you have cleared it correctly your idle speed should return to where it was originally, should be about 900 to 1000 rpm.
If you want to reset it turn the hexagonal headed bolt on the throttle lever (only one on it) clockwise to raise the revs or anti clockwise to lower it.

Yes carbs can be a pain (imagine 40's!) if you use the car every day they stay pretty clear but its when its laid up that causes the problems.
Now you know why they went the injection route.

[lanciamad]

When you say slotted screw furthest away, do you mean the one i have indicated as number 1 on this pic.? http://www.flickr.com/photos/lanciamad/3581807243, (this is a carb i'm using for spares).

[hutch6610]

Yes, screw marked as "1" is the fella - the idle/tick over jet.

[lanciamad]

Update - Took the idle jet out, and it was perfectly clear, i gave it and the carb a blow out anyway, as you instructed, and no difference.
With this not making a difference, i set about adjusting the hexagonal bolt (which i hadn't adjusted since the problem occured), and now the engine runs fine. Was taken to stanford hall and back without a hickup (240 miles), but is running at 1400rpm when hot, so will adjust that down next time its taken out.
Thanks for the help i really didn't have a clue when i started out    Just have to hope thats the last of it 

[hutch6610]

If your tick over increased the way it did chances are that the dirt or what ever just blew through on the run.
You will get dirt in the carb jet from time to time.

Hope it stays clear.

[rossocorsa]

a few years back i had a mint series 2 berlina that had stood for god knows how long it used to have intermittent carb issues I only cured them but thoruoghly blowing through every orifice in the carb with an airline after that it idled beautifully and revved like a racer so smooth those 1.6 engines if a bit lacking in torque