Constant "choke", no matter what

[bjm38]

Hi all,

We've finally bought the car we always wanted - a Traveller, 1964 1098cc, completely standard. But...

The car starts without using the choke, sounds to me like it's running rich (which it must be), also running a bit lumpily with poor acceleration. The choke seems ineffective, manually working the linkage on the carb makes no difference. Dashpot seems nearly empty...engine starts with a bit of a bump too, which I don't imagine is related.

Please help, car needed for wedding in a week!

Bernard

[biomed32uk]

As you say if it starts with out the choke then its rich.

Make sure the carb is not flooding, is there petrol coming out of the float chamber top ?, the needle valve may be sticking / damaged.

The jet, the piece underneath the carb with the pipe from the float chamber should move downwards when you pull the choke out, and move up again when you push it in, does that happen ?, if not then somethings not adjusted correctly, most likely the cable as there really is not much else to it, SU carbs are dead simple.

Not sure what you mean by a bump, but does the engine seem to fighting against the starter ?, if so the timing is too advanced, igniting the mixture while the piston is still on the compression stroke and fighting against you. Will also do damage like this long term as its putting lots of strain on the bottom end as a whole, and make some nasty rumbly noises.

The dashpot being low can cause flat acceleration, but so will all of the above, and together its going to be awful.

Think a good complete service is the order of the day here, check the carb for correct adjustment, check the timing and then the engine should be heading towards being correctly setup.

[simmitc]

Start with standard service items: Change the air filter and check the float level. Make sure that ignition is set correctly, check piston operation in the carb, centre the jet. Set the mixture correctly.

[bjm38]

Well, that's me taught - don't fiddle with the dizzy while the engine's running...got a HT belt that thoroughly woke me up!!!

First off, it looks like the ignition was seriously over advanced. As Biomed advised, that's what the bump was on starting. I've put the dizzy back by about 25 deg, I'll worry about fine-tuning when I finally get my head around that carb and get a reasonable idle.

Back later!

Bernard

[biomed32uk]

Been there, and done that, an armful of juice from the dizzy does sting, the bonnet catch hurts as that digs into the back of your head as you leap out as well .

You should be able to sensibly handle the dizzy without getting a belt, kind of indicates the leads may be breaking down and the cap is dirty or also breaking down.

Have a look at the carb and see whats going on with that, glad you are making progress.

Geoff

[bjm38]

Thanks Geoff - "slowly, slowly catchee monkey", it seems with the carb. The first pivot on the choke cable was moving, but the second that acted on the jet wasn't. After exercising the linkage a few times, it freed itself off. There's clearly a lot of slack in the choke cable, the engine just doesn't want to know with the jet actually pulled down. I think (hope!) it's now just a case of rich running, but I think I'll sleep on it with my sore head and weigh things up again after a few coffees in the morning.

Like many, I'd be lost without the kindness and patience of people on this forum. Thanks again.

Bernard

[biomed32uk]

Definitely, one thing at a time, lots at once and you have no idea what you have done to cure a problem.

The choke cable is easy to take any slack out of, clamping nipple at the carb end.

Jet going downwards makes it rich, back up is normal running mixture, apologies if I am saying what you already know.

You'll have it running fine soon I am sure. This forums great, I have been enjoying Minor ownership for the last 6 months, new to Minors but no stranger cars of this design.

Good luck, keep us posted.

[kennatt]

Its a simple matter to set the carb.Once you are sure the choke is off and the jet is returning fully up.Screw the large nut above the jet right in. Then screw out twelve flats,this is the basic setting, start engine,lift the pin on the side of the carb just a little not all the way up.,if the engine stalls ,too lean,screw it out slightly and try again,if engine speeds up and stay up ,too rich screw it in slightly and try again,when engine just speeds up slightly then falls back and runs a little rough you are about there,then set the slow running screw ,on the throttle linkage for a steady idle with the clutch depressed.

[bjm38]

Nearly there, I think - the one slightly troubling thing is, it was necessary to lift the pin quite a lot to get any noticeable effect. I've had the air cleaner off and the piston is sitting on the base of the carb body, it's travelling freely with a nice "clunk" when the pin's lifted. The resistance felt when the pin is pushed is when it touches the piston. *shrugs*

Thanks again everyone

Bernard

[bmcecosse]

Well yes - you have to take up the slack on the pin - and then lift the piston about 1/16". Or - just use a very thin screwdriver to lift the piston directly. Set the ignition by twiddling the dizzy back and forth to get the best idle - and balance that again with adjustments to the idle speed and more piston lifting. Each adjustment affects the other...so it's a balancing process to get it right. Then check the engine is not pinking, and finally a plug colour check after a good long/hard run.

[bjm38]

Thanks, Roy - I just took the wording about the lift pin literally.

She sounded pretty happy after a 15 minute midnight drive last night. I think I have the settings pretty close, but I'll wait for a dry day before venturing any distance. The door windows are missing their weather strips, so I don't want doors full of water.

I just don't get how a dealer who specialises in these cars can make such a bejaysus of setting up an engine.

Bernard

[bmcecosse]

Depends which 'specialist dealer' you are thinking of...... Nothing surprises me now.

[bjm38]

They deserve a chance to make amends - it might have been some 16-year old apprentice...anyways, I think it's against forum T&Cs to name anyone.

Bernard

[bmcecosse]

Probably - but then they shouldn't be letting 16 year old apprentices work on your car unsupervised - or at least with the work properly checked afterwards!

[rayofleamington]

The door windows are missing their weather strips, so I don't want doors full of water.

The doors will get water inside, even with the weather strips - just at a a slower rate!
The inside bottom of the door needs to have plenty of drain holes, and plenty of waxoil (or similar stuff) for rust protection.
Blocked drain holes are common - if so they need to be poked out with a piece of wire.

[bjm38]

Thanks for that Ray,

It looks as if the door bottoms have been re-done without drain holes. I understand the car was restored about 12 months ago, there are certainly a lot of new parts on her. I'd better get the door cards off to see if the holes have simply been painted over...!

I was a little surprised to find the car still has its original engine, as witnessed by its original green log book.

Bernard