2.25 petrol running rich only when warm

Hi,

Just to be clear, this is an ongoing restoration of a lightweight and the vehicle hasnt been on the road for 15 years. We've checked out the 24v/10v ignition system, timing set by ear, points and condenser replaced and gaps set. It starts first time every time when cold and runs fine but the warmer it gets, the richer it gets and starts bogging down and chugging black smoke. Oil bath has been removed, choke returns to open position, lead additive makes no difference. Brand new spanish weber 34 ich carb. Engine seems to have plenty of power. We're stumped.

Brand new Spanish Webber would be my first thought.

Col

I've never understood what people have against these carbs.

Anyway,back to theoriginal problem. Could it be the flexy air pipe collapsing internally? When it starts bogging down,try taking the flexy off and see if it makes any difference to the running. It costs nothing to do,and needs no special tools or knowledge!

Tall Ratbag said:

I've never understood what people have against these carbs.

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I agree. I've had 34ICH carbs on both the Series Landies I owned and never had a problem with them.
The original problem could well be down to the carb, though. A few thoughts:
- float level may be too high (speck of dirt in the float valve?)
- wrong jets fitted
- jets loose
I'd be surprised if a brand new carb had any of these issues, but still worth taking the top cover off and making sure everything is clean and tight.
Also worth checking that the points/condenser are not faulty. There's a lot of nasty replacement points/condensers out there that quickly fail and the symptoms can be similar to a carb problems.

Float level was my first thought.

What condition is your PCV in? Mine was split and caused havoc with running,

I’ve got a similar issue with mine at the moment, running rough when warm, same carb, but it’s bogging down on full throttle, appears to be a timing / carb tune issue

Tim_AM said:

What condition is your PCV in? Mine was split and caused havoc with running,

I’ve got a similar issue with mine at the moment, running rough when warm, same carb, but it’s bogging down on full throttle, appears to be a timing / carb tune issue

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You're a bit late to the party

kermit_rr said:

You're a bit late to the party

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So I am!

It was suggested as a similar thread! I thought it was current! My bad!