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Alpina poor running

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I have a 350 Alpina 213, history unknown but supposedly restored; it’s still got the original Bing carb.

The bike starts after a few kicks but not with the choke - won’t start if you use it. More of an issue, though possibly related, is if I drop down to first for any difficult bits (I use it for greenlaning here) the motor doesn’t respond to the throttle, dies and won’t restart unless I give it a long bump.

I’ve had the carb apart and cleaned it as best I can, air filter cleaned and oiled, and plug changed, though no further work done yet - any suggestions? I assume it’s running the original ignition setup but haven’t had the side off to check.

 

Bing carb floats are quite prone to failing, becoming heavy over time. Could it be this as i would suspect it would be more likely to show up at low revs?The floats are the same as used in BMW CV type Bings.

  • Author

Checked the float, it’s fine...

Edited by mick annick

It's very odd for an engine to start from cold without using the starting circuit. This may sound silly but are you sure you know which way the starting lever should be for on and off?

  • Author

The guy I bought it from said up for starting, down for running, and once warmed up it runs a treat with the lever down which presumably it wouldn’t if it was being overfuelled by the starting circuit?

I had to look at a Bing 84 from a Sherpa

-Lever down (axle up)- Choke on

-Lever up (axle down)- Choke off

  • Author

Thanks Carl, I’ll try it that way round - let’s hope it’s that simple!

19 minutes ago, mick annick said:

Thanks Carl, I’ll try it that way round - let’s hope it’s that simple!

If you had the operation back to front it still shouldn't start, i.e. no choke. Try another carb.

  • 3 weeks later...
  • Author

Icehopper

 

I bought an ultrasonic cleaner, stripped and cleaned the carb and it’s much better though won’t tickover unless the screw is right in. I’m trying to get some new jets at the moment.

 

Mick

 

 

15 minutes ago, mick annick said:

Icehopper

 

I bought an ultrasonic cleaner, stripped and cleaned the carb and it’s much better though won’t tickover unless the screw is right in. I’m trying to get some new jets at the moment.

 

Mick

 

 

 A new slide will likely fix your idle issue.

Edited by motovita

  • 2 weeks later...
On 10/1/2019 at 3:58 PM, motovita said:

 A new slide will likely fix your idle issue.

Seconded, a new slide off of bultaco uk will do the Job. I had exact same issue. 

Bing carbs slide is made of the same material as the body and they wear out, you end up with a horse shoe worn in the engine side of the slide ?

Edited by WJSmith

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