Solex 30 pict 2 - fast idle cam question

[Lanigiro]

Hi all,
First post……
Dumb question maybe, but I could use some help. Rebuilt the carb on my ‘68 1600. First time rebuilding the carb and it looks like I messed something up.

Engine started right up (good)
Idle was notably high (not so good)

When I went to adjust the fast idle cam, I realized that there was no spring tension on the cam and it was just loose and flopping around.

Before I remove the carb and take it apart….. what gives the fast idle cam its spring return? I have about 6 different Solex exploded diagrams and am not sure where to start.

Thanks for any guidance.

[SGKent]

I am guessing that there is a procedure to put the fast idle cam on a certain step and adjust the speed to a specific RPM. When the choke opens, usually the fast idle cam will go back to the normal position by weight or a return spring. To troubleshoot I would back the choke off so it isn't holding the choke mechanism in the cold position, and then take a look at it. Bentley has some good write ups on Solex carbs in the manual and the photos may answer your questions. Good Luck
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[kreemoweet]

[Lanigiro]

Thanks for the pointers. I think I may have not attached the thermostat spring to the choke properly.

Will review Bentley manual in the morning.

[Lanigiro]

^^^^ improperly

[Wildthings]

Maybe just spray the cam mechanism with some lube.

FWIW, I typically don't touch the carb adjustments when doing a carb cleaning/rebuild as if the carb had been running well the prior adjustments will typically still work well with the same adjustments. for the various adjustment screws I turn them in all the way gently, counting the turns so I know where to reset them too. Everything gets tested though once the engine is running to see if they work correctly.

[Lanigiro]

[SGKent]

do you mean the coil in the thermostat or the spring on the butterfly?
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[Lanigiro]

I think I set up the coil in the thermostat ok, but not sure about the spring on the butterfly.

[mikedjames]

The easy way is to loosen the three clamping screws on the choke heater assembly then rotate it, the choke flaps should open and close as you move it clockwise and anticlockwise, and you should be feeling the springiness of the bimetallic strip spring.

Set it to just about closed and then as it heats up with the power from the coil it shoould rotate and let the choke flap open and allow the stepped idle cam to drop by gravity when the throttle is operated after the choke heats up. The stepped cam gets locked by the return spring on the throttle lever until you touch the throttle.
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[Lanigiro]

@mikedjames
That was what I needed! Thanks so much!!!! I just twisted the choke heater element about 10 degrees and the butterfly is where it needs to be.

First time rebuilding the carb in this. My dad was the original owner and the carb was probably touched last in the 90s.

Just adjusted the idle mixture and went for a drive. Of all the cars I’ve ever had this one has the most smiles per mile.

Thanks to all for the advice !!