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TR2/3/3A tough to pull choke - TR3 H6s

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NutmegCT

NutmegCT

Great Pumpkin
Bronze
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Decided to find out why my choke knob is so tough to pull out.

Pulling on the knob *as hard as I can*, it slowly comes out about 3/4 inch. Can't even see the notches in the stem.

Looked at the cable run. No kinks or bends.

Looked at the choke/jet lever connection. Per spec.

Disconnected the choke cable from the jet lever linkage. Choke pulls easily all the way to max. Tried moving the jet levers by hand. They are *hard to move*. Push very hard and the lever finally "yields" and moves full distance.

Reconnected the cable to the linkage, and removed the jet lever return springs. Choke pulls so much more easily, and for a full two inches.

The problem isn't in the cable or linkage.

Even with only one spring connected, the choke pulls very hard. There's some major resistance, I'm thinking in the jet bearing mechanism (?).

So I'm wondering just what is making it so hard for those jet lever arms to move. Linkage is definitely not binding.

Is there something in the jet bearing assembly that can stick and/or cause all that resistance?

Possibly related: previous owner reports he never used the choke.

I realize some folks say the choke is hard to pull - but I'm thinking mine is a much tougher than it should be.

Thanks.
Tom
 
Aloha Tom,

The jet is sealed in the jet bearing assembly with two graphite impregnated cork seals. These over time may have lost the lubricant and are not let the jet move easily. Sometimes the cork seals which tend to dry up and crack are replaced with neoprene o-rings. This change results in a good seal, but the o-rings really grab the jet and it is hard to move. I suspect you either have dried up cork seals or o-rings in the jet bearing assembly.

I never use the choke on my TR3A, but then I never have to do a cold weather start.
 
Tom,

When the car is warm does it maintain idle OK? Try a little silicone spray on the outside of the jet and linkages when fully extended. Then work it back and forth and see if that loosens it up. As Dave said the cork seals do dry up. Choke cable disconnected or you will kink it.


If the car isn't maintaining idle and the silicone spray doesn't help the situation. The jet may not be centered to the needle properly causing it to bind. If this is the case I'm gonna have to ask some one else to type out the procedure for you. I'm down one hand for a bit.
 
I just posted a question about this same problem about a week ago. I had rebuilt my carbs and started having the same problem. I ended up taking out the jet assembles and removing the new o-rings and coating them in bearing grease and reinserting them. It solved the problem immediately. I first tried silicone and litheum grease, but neither worked until I used multi-purpose bearing grease. Good luck
 
One trick is to floor the throttle when you're pulling the choke knob- then you're not trying to open the throttle (fast idle) with the knob. Makes some difference, in my experience.

Also, if the jets are hard to pull down, they may be hard for the return springs to pull back up, too. It's worth checking that they are coming back hard up against the nut once in a while- it's easy to put your fingers down there and see if you can push them back up at all. I actually have a (slightly cheesy) extra return spring hooked between the front operating arm of the lever linkage and the body of the car (TR6); I found I needed it. I have the o-rings in there. I have SU H6's on it.

Hope this is helpful! Pete
 
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