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Title: Choke link to throttle - DATR Post by: JohnFol on March 25, 2022, 02:15:17 PM Hi all, just in the middle of setting things up and spotted what might be an issue. Symptoms from cold are stalling when pressing accelerator so I'm walking through the setup i.e. float levels, butterfly gaps, clearing out debris, blowing air through . . . However I think I've spotted a bigger issue
1st Image is from Haynes manual and it shows the thermostatic housing has an adjustable screw linking it to the "throttle lever". 2nd Image is what's actually on the car. Apologies for the angle, but what I hope it shows is the side of the thermostat housing has nothing coming out of it. 3rd Image is looking from the "throttle lever" through a hole that looks like there was a lock nut, directly into the thermostat housing Would it be reasonable to assume the adjustable screw is missing? Title: Re: Choke link to throttle - DATR Post by: JohnFol on March 25, 2022, 02:16:30 PM Haynes Picture
Title: Re: Choke link to throttle - DATR Post by: JohnFol on March 25, 2022, 02:16:51 PM What I see
Title: Re: Choke link to throttle - DATR Post by: peteracs on March 25, 2022, 05:10:26 PM Hi John
Yes you should have a bolt which is adjustable which pushes against the thermostat on the carb as you mention and this opens the throttle until the housing gets up to temp. Peter Title: Re: Choke link to throttle - DATR Post by: squiglyzigly on March 25, 2022, 05:59:44 PM Definitely missing the fast idle screw. It is there to hold the revs up by a stepped cam which is linked to the bi-metal choke. Although that statement is an over simplification it’s essential to keep the engine from idling too low/stalling when the engine is cold.
Title: Re: Choke link to throttle - DATR Post by: JohnFol on March 25, 2022, 06:03:43 PM So, nothing complex like a cam, or rounded end, just a simple threaded bolt?
Title: Re: Choke link to throttle - DATR Post by: squiglyzigly on March 25, 2022, 09:38:44 PM Yes just a bolt but it is an unusual fine thread with the tip wasted with a flat point with no thread.
The original is a unique piece but I’ve used a bolt in the past with a locknut. Title: Re: Choke link to throttle - DATR Post by: peteracs on March 26, 2022, 10:10:29 AM Hi
The cam is attached to the element within the bell housing where the water goes. As the water heats it moves the cam which the bolts presses against. Peter Title: Re: Choke link to throttle - DATR Post by: JohnFol on March 26, 2022, 08:46:29 PM I ran the engine earlier and it seems to operate the wrong way round, ie the thermostatic strip closes the choke flap rather than opening.
Nothing surprises me any more Title: Re: Choke link to throttle - DATR Post by: peteracs on March 26, 2022, 11:36:27 PM Hi John
Something is obviously installed the wrong way round. It is pretty simple to disassemble and check it with the carb on the car. Peter Title: Re: Choke link to throttle - DATR Post by: squiglyzigly on March 27, 2022, 07:31:14 AM There are two types of choke for carbs of this era. One spring is wound clockwise and the other anti-clockwise. Sounds like the wrong one may be fitted. Maybe that’s the reason why someone removed the fast idle screw as it would hold the revs high when the engine warms up instead of during cold start.
This design of bi-metal auto choke was fitted on numerous cars of that era but they aren’t all the same direction of operation. I can’t remember which way the Beta is wound off the top of my head but if you remove your housing and warm it in the kettle you will see what you have. Title: Re: Choke link to throttle - DATR Post by: JohnFol on March 27, 2022, 12:24:32 PM The good thing about the screw being absent is I can see the stepped cam of the choke, and hence which way it turns when heating up.
I have a weber book arriving tomorrow and hoping to see a few more pictures, ie which way the coil is mounted Many thanks for the response, much appreciated |