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6 cyl Bristol cars Type 400 to 406 - restoration, repair, maintenance etc

Winter degredation

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Old 21-02-23, 11:26 AM
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Default Winter degredation

I went to start the 403 after the winter and found little 'mushrooms' on my carb cover where there are pin holes in the epoxy coating!

Worse was to come though. The engine appears to have nipped up and the mixture (choke) cable broke at the dashboard end.

Is there a source for repair or replacement of these?

I was surprised to see that it goes through two nearly 90 degree bends in the engine compartment to get to the carbs. Is there a better way to run the cable?
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Old 23-02-23, 03:15 PM
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I got control cables remade by a local engineer/motorbike shop, if you can't find someone locally I think Speedy Cables near Swansea could do it for you.
I agree its not the best layout but the Battery box is in the way of a direct pull cable. Also I find the chokes do not fully close so I tend to do that from under the bonnet while the engine warms up on the hand throttle. Perhaps a stronger spring on the connecting lever would help overcome the issue I mentioned.
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Old 01-03-23, 10:52 PM
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Sorry for the late repsonse but I am only recently at the stage of reinstalling all the controls through the bulkhead on my 403, and have only just sorted out how my choke (mixture control) works. Whether or not my setup is original I have no idea. There are more holes in the bulkhead than I need! However, I took plenty of photos before I dismantled everything and can confirm that my choke cable goes through the bulkhead immediately right of the left hand glove box, near the top of the available space. It is above the speedo cable, the oil temp and press and the rev counter cable which also go through to the right of the left hand glove box. It then has to bend right and then left to be fitted to the linkage that joins the chokes on the three carburetters. It goes to the middle of the linkage. Geoff talks about a stronger spring, but there is no spring on mine. I have overhauled my carburetters myself, and the chokes have a built in "snap" part way through their movement, which provides a "two-stage" feel to the choke as one pulls out the choke knob. The two stage feature is described in the Owner's Manual. There is no "turn to lock" on my choke cable, which also confirms, IMHO, the no-spring design. The choke is simply pulled out or pushed in. I have also overhauled my choke cable, taking it apart and cleaning and regreasing the inner before putting it back together. It works very smoothly and with no difficulty.

I have seen photos of other cars where it looks as if the choke cable has been routed much lower down, and more or less in line with the knob on the dashboard, underneath the battery compartment. If this were the case, the path within the engine compartment would be more tortuous. However, a properly maintained and well lubricated bowden cable should be able to cope with a couple of bends no problem.

Mike
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Old 04-04-23, 07:28 AM
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Does anyone in the Surrey/ West Sussex area have a 401/3 starting handle that I could borrow to try and ease my engine over with?
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Old 22-05-23, 08:59 PM
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Finally got it running. It appears that the problem was hydraulic locking.
The rear two carbs are gushing petrol. Presumably the float needles are not closing off the supply and the lack of pressure keeps the pump pumping.

Are the Solex carbs easy to service? Are parts available?

Just to make life easy the starter button isn't working and I am having to short the two solenoid terminals to turn the starter motor over
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Old 23-05-23, 07:10 AM
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First thing to do is try a strike with a rubber hammer, to unstick the valves/float.
It could be the needle valves sticking, or the float itself could be stuck in the chamber and not able to rise. It is fairly easy to get to - undo the main fuel feed banjos, then the three top bolts on each carb, and take the lids off the carbs. The needle valve is screwed into the lid, and you'll see the float chamber in the body. You can then see whether the float itself is stuck. To remove the float you first have to pull out the hinge pin and lever ( which rides up and down on the float top ).
Parts are fairly easy to get as Solex carbs were used on many other vehicles - I got some needle valves from Eurocarb Ltd. who also do jets. The 405 uses the 1.5 ( 150 ) size and it is most likely the same for your engine - this should be marked on your needle valves. If you do replace them, you should match the height at which the valve closes, using the washers under it. This sets the float chamber fuel level.
If you are a BODA member, I would recommend getting the Pegasus Parts set of washers for the main fuel feed banjos. They solve leaks there without having to tighten the bolt too much - this thread in the carb lid is not strong.

For the first start in a while it is always good to use the hand priming lever on the pump as this shows up whether all is well. You can hear the carbs fill up and then the lever should suddenly have no resistance once all three valves are closed properly.
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Old 24-05-23, 02:48 PM
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Thanks Joe,
I used the hand primer and could see the petrol squirting into the chamber on the rear two carbs. I will take off the lid and see what is happening below.
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Old 26-05-23, 12:50 PM
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Quote:
Originally Posted by peterg View Post
Finally got it running. It appears that the problem was hydraulic locking.
The rear two carbs are gushing petrol. Presumably the float needles are not closing off the supply and the lack of pressure keeps the pump pumping.

Are the Solex carbs easy to service? Are parts available?

Just to make life easy the starter button isn't working and I am having to short the two solenoid terminals to turn the starter motor over
I rebuilt my 403 carbs myself using parts from Gower and Lee. The parts were purchased by the previous owner in 2001, but Gower and Lee are still around and seem to be knowledgable on classic Solex. Classic Carbs also have the parts, but I have no first hand info on this company.

Starter solenoid - if you have the proper one, it will have a mechanical button under a rubber hemisphere on its top. Just press this if the button on the dash doesn't work. My solenoid was open circuit on its coil, which is why the dash button didn't work. AES (and others) have a replacement.
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Old 27-05-23, 10:37 AM
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In the end I bought a couple of service packs from Southern Carburetters in Crawley but didn't use them

Took the tops off, cleaned as much of the crud as I could and sprayed the rest. made sure the float was moving (rear one was seized) and the float needle worked (both seized). Reassembled and both were petrol tight, although the threads on the banjo bolt in the middle carb are worn.

Engine started almost immediately but it smoked and took quite a time to settle down to an even tick over.

Now to sort out the choke cable, starter button, solenoid and seized rear brake.
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Old 13-07-23, 10:51 AM
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I replaced the choke cable with one bought from Standard 8 & 10 Spares @ 50. Fits well and has the right end for the knob to locate on.
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