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Throttle return spring
Posted: Mon Mar 18, 2013 2:34 pm
by Tapitha
I have had my carb off the manifold and have now refitted it. However I am baffled as to how to refit the throttle return spring. I have searched the Haynes manual and the BMC workshop manual and nowhere can I find a diagram of where and how it fits. The one I had on the car went from the throttle lever to the manifold/exhaust clamp. Now I cant find anywhere to fit it to the throttle lever at the carb! It is always the simple things that cause the most aggravation!!
Thanks,
Mike
Re: Throttle return spring
Posted: Mon Mar 18, 2013 2:49 pm
by chesney
On mine (HS2) there is a metal plate attached to the end of the throttle lever, with a hole in one end for the spring, on the same clevis pin type thing the throttle cable attaches to.
Re: Throttle return spring
Posted: Mon Mar 18, 2013 4:01 pm
by Declan_Burns
Here's where it is connected to the carb.[frame]

[/frame]
And here's the bracket with the little hole on the exhaust clamp that the other end connects to.[frame]

[/frame]
Regards
Declan
Re: Throttle return spring
Posted: Mon Mar 18, 2013 4:05 pm
by bmcecosse
Worth checking the spring isn't worn away where it hooks round at each end. When it snaps - the throttle goes fully open and the car accelerates dramatically.... Can be a bit embarrasssing.....and dangerous!
Re: Throttle return spring
Posted: Mon Mar 18, 2013 5:03 pm
by philthehill
Declan
I note that you have fitted an additional bracket on the exhaust front pipe just below the flange joint. Any particular reason?
Re: Throttle return spring
Posted: Mon Mar 18, 2013 6:18 pm
by Tapitha
Thanks Declan for the excellent photos. I don't have any of these brackets so I will do some metalwork. I think I will get a new spring to be safe. The arrangement of the fixings for the throttle spring looks like an afterthought. Surely Morris could have come up with someting better! My MGB has a better solution.
Thanks everybody for help and advice.
Mike
Re: Throttle return spring
Posted: Mon Mar 18, 2013 7:32 pm
by JOWETTJAVELIN
I'd hazard a guess that Declan's additional exhaust clamp is to steady the whole system to prevent vibrations and/or knocks to the system from damaging the gas-tight seal at the manifold resulting in a blowing exhaust, which causes a whole host of trouble.
Re: Throttle return spring
Posted: Mon Mar 18, 2013 8:03 pm
by MikeNash
Ooooo! - Declan's got one of those lovely cast manifold/exhaust pipe clamps! Not like my rotten tinny thing. MikeNash.
(I see I've just reached my 500th posting and am officially an Addict!)
Re: Throttle return spring
Posted: Mon Mar 18, 2013 8:08 pm
by GeordieDave
bmcecosse wrote:....the car accelerates dramatically....
I can't wait for my spring to snap so I can finally feel the raw untamed power

Re: Throttle return spring
Posted: Mon Mar 18, 2013 8:11 pm
by bmcecosse
In the outside lane of a Mway at the time - passing a line of HGVs.....I can confirm the speedo works v well right round into the fuel gauge.....before I was able to pull over and switch off......
Re: Throttle return spring
Posted: Mon Mar 18, 2013 8:56 pm
by chesney
I've always admired the way my HS6 has the springs on the actual carb, completely integrated system.
I had a return spring stretch on me once (bloody new parts!) and that held the throttle at approx 2000rpm minimum, if not more. Had to pull into a petrol station and the poor old lady in a pug 206 looked absolutely terrified and only put about 8 quids worth in, clearly the sight of a teenager gunning the throttle had done it

Re: Throttle return spring
Posted: Mon Mar 18, 2013 9:04 pm
by JOWETTJAVELIN
These 1100 engines can't half fly when you floor them, y'know!

Re: Throttle return spring
Posted: Tue Mar 19, 2013 6:04 am
by Declan_Burns
philthehill wrote:Declan
I note that you have fitted an additional bracket on the exhaust front pipe just below the flange joint. Any particular reason?
As JJ has explained and it prevents the exhaust rattling against the aperture.
Regards
Declan
Re: Throttle return spring
Posted: Tue Mar 19, 2013 10:12 am
by philthehill
Declan
Thank you for your explanation but in my experience if you have the correct/serviceable engine/gearbox mounts, the engine steady bracket & rubbers are in good condition and the exhaust has been fitted correctly the exhaust pipe should not rattle against the chassis apperture or anywhere else.
Re: Throttle return spring
Posted: Tue Mar 19, 2013 8:01 pm
by MarkyB
In my experience the manifold to exhaust pipe joint is very prone to leaking, extra support may well alleviate this.
Re: Throttle return spring
Posted: Wed Mar 20, 2013 3:40 pm
by JOWETTJAVELIN
Indeed, on Mini's, BMC 1100's etc there is an exhaust clamp to the gearbox for that very purpose.
Re: Throttle return spring
Posted: Wed Mar 20, 2013 9:39 pm
by Tapitha
Played safe and bought new spring and metal bracket thingy. Now I want it to stop raining and snowing so I can finish all the work. No garage so I freeze!!!!
Mike
Re: Throttle return spring etc
Posted: Thu Mar 21, 2013 4:59 pm
by Tapitha
Dry this morning so I fitted the new bracket and spring. Now I need to know how much tension to put on the spring? Should the bracket on the Manifold/exhaust joint bolt point up, down or sideways to adjust the tension? Another problem that has developed
is that the choke is sticking on and not coming off when I push in the knob so I have to open bonnet and move it off by hand? Any solutions as to why this is happening and what should I do? Also the engine is running very fast when it should be on tick-over although I have adjusted the idling and cam stop screws. It is OK while on my driveway but revs wildly once I have driven off and then stop at the road junction or roundabout. Everybody looked when I stopped for petrol!! Three months laid up doesn't seem to have done much good! Yes I know I should drive the car but I have been away for the winter.
Thanks,
Mike
Re: Throttle return spring
Posted: Thu Mar 21, 2013 9:09 pm
by mike.perry
Adjust the bracket so that there is enough tension in the spring to hold the throttle closed but not too much to make the accelerator pedal too heavy.
Choke return. The coil spring around the jet should be strong enough to close the choke. Make sure that there is a little slack in the inner cable and check by hand that the jet will move up and down freely. If it does not then check that the jet is centred correctly and give it a light smear of oil.
The inner cable should be given a twist in the clamp so that it holds the choke knob out which is then twisted to release it. The alternative is the clothes peg. Note that if entering concours points will be deducted if the peg is not wooden, and it should be clipped behind the rear view mirror when not in use.
Re: Throttle return spring
Posted: Fri Mar 29, 2013 12:04 pm
by Tapitha
Managed to get throttle and choke working properly yesterday and went for a 5 mile run before laying up with SORN for a month. MOT expired yesterday and tax disk on Sunday. Weather stopped me getting ready for MOT so it will have to wait as I am away for 3 weeks. Back on road hopefully by May ready for the Rally on 15/16 June.
Mike