From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.

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From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#3908

By Matt - Sat Jul 19, 2014 8:09 am

- Sat Jul 19, 2014 8:09 am #3908

Hi chaps.
My 2004 Iron barrel bullet with Amal carb runs great. Really great, starts easily etc.
One not so important but annoying feature though is as the title describes. It's always done it.
When the bike's ticking over if you open the throttle quickly the engine dies, you have to be gentle and tease it a bit and then you're off.
Additionally sometimes she takes a long time for the revs to drop to tickover having just pulled up at a junction for example, again, not a problem but potentially related information?

Is there anything I can do about this or is it just a quirk to live with?
Thanks.

From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#37769

By PeteF - Sat Jul 19, 2014 8:37 am

- Sat Jul 19, 2014 8:37 am #37769

Float height to high might give all these symptoms

Classic C5 Euro 4 at the moment.
Also CBf250.

From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#37770

By Frank - Sat Jul 19, 2014 9:03 am

- Sat Jul 19, 2014 9:03 am #37770

Air leak somewhere?

From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#37773

By Thack - Sat Jul 19, 2014 9:46 am

- Sat Jul 19, 2014 9:46 am #37773

At risk of sounding like a stuck record, what you've described is typical of the Amal carburettor. Sudden weakening of the mixture on rapid throttle opening from tickover is a characteristic of them. However, you will be able to improve it a lot by fitting a richer slide (a lower number). Seriously, your symptoms suggest that the slide is far too weak - I'd be tempted to try the next size down, or more likely two sizes. Having said that, PeteF is spot on to suggest that you check all the usual stuff like float height, which will cause all sorts of problems if wrong. The long time to return to tickover is worrying and does suggest a possible air leak between the carb and the head, or between the carburettor slide and body. The latter occurs on Amals because the slides and bodies are both prone to wear. So, 1/ check for inlet air leaks; 2/ check if the slide is a loose fit in the body; 3/ fit a richer slide.

From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#37776

By hubb - Sat Jul 19, 2014 10:02 am

- Sat Jul 19, 2014 10:02 am #37776

This may be a total red herring but last year I did two things to my bike; firstly I took great pains to get the timing spot-on and secondly fitted a gauze bell-mouth to the monobloc. No performance increase as it was already running well,as yours is, but I noticed it no longer needed the throttle feathering to stop it cutting out after ticking over for a while at traffic lights etc.,pick up was instant and reliable and has continued to be so.

From tickover a rapid throttle oppening causes the engine to die. 04 Bullet 500 Amal.#37802

By simon - Sat Jul 19, 2014 11:12 pm

- Sat Jul 19, 2014 11:12 pm #37802

The spit cough and die scenario after idling at the lights which my 350 fitted with an 11/8" 389 suffered from was cured by the combination of fitting a smaller idle jet ( the existing one being more suitable for a 500) which allowed me to set the idle screw in the right spot and also replacing the 31/2 cutaway slide with a 3. It now works perfectly.