Club 80-90 Forums

Still having issues with my carb, it starts ok from cold with a bit of encouragement from the accelerator pedal. But revs do not drop when engine warms up. In the past a tap on accelerator pedal after a couple of min warming up would hear the revs drop, what part of the Carb does this reduction in revs??

The choke’s not coming off ?
You can move the auto choke to the Summer setting to make it come off sooner or maybe the spring is damaged .
Is the choke pull down unit ok?
David

Summer setting??

there is a cam on the auto choke with three steps, check it's return spring is in place and working. use carb cleaner to clean the springs and cams followed by a light oil and ligt grease to lubricate them . there are two springs.

Also check for air leaks, perished vac pipes, split diaphrams in the pull down and second stage unit and also base gasket.

jrt wrote: ↑01 Jul 2025, 21:25 The choke’s not coming off ?
You can move the auto choke to the Summer setting to make it come off sooner or maybe the spring is damaged .
Is the choke pull down unit ok?
David

Thanks David, the choke flap closes when using the cold start procedure and opens when warmed up but this does not reduce the revs. Donot understand Summer setting though.

TwinTurbo wrote: ↑02 Jul 2025, 05:41 Summer setting??

there is a cam on the auto choke with three steps, check it's return spring is in place and working. use carb cleaner to clean the springs and cams followed by a light oil and ligt grease to lubricate them . there are two springs.

Also check for air leaks, perished vac pipes, split diaphrams in the pull down and second stage unit and also base gasket.

Thanks, never fully understood the cam settings and steps, will check all you have mentioned. I did in the past clean the area you mentioned and it did work, but the rev issue not dropping came back later.

over zwlous cleaning can dislodge the cam sprin, it's a pain to relocate but doable .

If it's sat there revign high, give the cam a prod and see if it moves and drops the revs. 

TwinTurbo wrote: ↑02 Jul 2025, 07:22 over zwlous cleaning can dislodge the cam sprin, it's a pain to relocate but doable .

If it's sat there revign high, give the cam a prod and see if it moves and drops the revs. 

Thanks, is the cam easy to locate, searched on line but cannot determine its location. Need to rebuild carb also, as last breakdown the RAC got me going , seen kits on ebay but costs vary.

it's between the autochoke housing and the main body. 

TwinTurbo wrote: ↑02 Jul 2025, 07:32 it's between the autochoke housing and the main body. 

Thanks again.

3 screws undo on the side of the choke and you can move it to allow for more choke in the Winter and less in the Summer but this probablisnt your problem but handy to know.
David.

jrt wrote: ↑02 Jul 2025, 11:29 3 screws undo on the side of the choke and you can move it to allow for more choke in the Winter and less in the Summer but this probablisnt your problem but handy to know.
David.

Thanks, need to tackle carb rebuild as well, putting it off att.

Is it by chance your ecelerator sticking not the carb?
Having a bit of an issue with mine at moment and need to lubricate conduit.

SurfT25 wrote: ↑02 Jul 2025, 14:55 Is it by chance your ecelerator sticking not the carb?
Having a bit of an issue with mine at moment and need to lubricate conduit.

Thanks, I dont think its the Accelerator cable but will have a look, all pointers and advice points to the Carb, viewed James Akers video on it which are great, just need to buy the rebuild kit, plenty on ebay but prices and contents vary.

why do you think youneed to rebuild it?

Contents is usualy just seals and the acceleration pump ( which there are two types and one is not in most kits ).

TwinTurbo wrote: ↑02 Jul 2025, 17:53 why do you think youneed to rebuild it?

Contents is usualy just seals and the acceleration pump ( which there are two types and one is not in most kits ).

Hi, I have had problems to do with the carb which i mentioned in a post last year. The last incident was on the A3, driving along the van coughed and spluttered once but kept going, got to Morrisons, did my shopping drove off and engine comletely died and would not restart, managed to free wheel off road and called RAC. The RAC guy was very helpful, took the top off the carb down to float chamber, cleaned it out and jets. I did notice that the gasket looked as if it had split (it looked like a rubber or plastic gasket but replacement ones on line appear to be of a different material so unsure if they are the same), he put it all back together and engine started fine and got me back home. So thought a rebuild was the best solution. Maybe a rebuild is the wrong term in this case. Just to add the small cone filter was clear.