Stalling after choke, only one carb getting fuel

[davidvincent]

Hi all

I've read other posts regarding the poor idling and stalling once engine drops off the choke/revs - which is what I'm getting, however after going through a few things I'm still stumped, and I've noticed that (when I was cleaning the carbs) the left carb is getting plenty of fuel but the right seems almost dry, actually if i stopped the engine and checked inside the carbs, the left was trickling fuel through for around 20 seconds after turning off the ignition, but the right was omitting a stream of either steam or smoke, but with no fuel coming through... I have no idea if this is normal, but I haven't seen t before.

What I've checked (ruled out) so far (prior to seeing the differences in fuel reaching the carbs):

- Coil
- Distributor Cap
- Rotor Arm
- Leads
- Plugs
- Fuel Level
- Fuel Filter (was changed 6 month ago)
- Fuel/Air solenoid
- Idle Stabiliser
- Ignition Control Unit

If any one could throw a little light on this, I'd appreciate it. My next check was going to be the fuel pump.

Thanks all

David

[davidvincent]

any other ideas folks?

thanks
David

[sarran1955]

Hello,

This may be of help..

http://www.youtube.com/watch?v=4qayyc9Z4E0" onclick="window.open(this.href);return false;

Then part 2 on the same page..

The left hand carb is the master.. to really set this up properly.. you will need the tools in my video..

Not expensive.. and quickly pays back in better fuel consumption..

This is an excellent guide..

http://itinerant-air-cooled.com/viewtop ... 224976e975" onclick="window.open(this.href);return false;

Cordialement,

[bigherb]

Hi all

actually if i stopped the engine and checked inside the carbs, the left was trickling fuel through for around 20 seconds after turning off the ignition, but the right was omitting a stream of either steam or smoke, but with no fuel coming through... I have no idea if this is normal, but I haven't seen t before.

David

Where was the fuel trickling from?

Shouldn't worry about the smoke, when the engine stops one of the cylinder inlet valves is always open letting the hot gasses come up from the cylinder.

[davidvincent]

Thanks for the feedback folks, will check the vids etc tonight.

The fuel was trickling within the carb itself, sorry if I made it sound like it was leaking, it wasn't.

[bigherb]

The fuel was trickling within the carb itself, sorry if I made it sound like it was leaking, it wasn't.

Shouldn't be doing that. The float valves are leaking or the the float level is to high. They may have been replaced and the wrong washer used under the valve, the washer should be 1mm thick all the other carbs use a washer 0.5mm thick.

[davidvincent]

[/quote]
Shouldn't be doing that. The float valves are leaking or the the float level is to high. They may have been replaced and the wrong washer used under the valve, the washer should be 1mm thick all the other carbs use a washer 0.5mm thick.[/quote]

Hmm, I did wonder... so what happens is after I turn off the engine, the left carb still has fuel trickling into it for around 20 seconds. I'm not that savy on the topic of carburettors, so I'll need to have a read up on what you suggested there - thanks for the info, much appreciated.

Perhaps a trip to Southern Carburettors is order for a service.... although that would be around £120...

David

[benlawlor85]

Hi,
I was helping a friend out this weekend tho had a similar problem engine stalls at low revs. Turned out that the Idle circuit solenoid was loose. but worse than that the threads had been stripped in the carb. It had some sealent all around it a PO attempt to seal it i guess. This will obviously give a huge airleak and be sucking in air causing the engine to stall. Carb out, drill out and helicoil is the only solution i could think of. But not having the kit it was just some more sealant for the time.
Its worth checking for air leaks all over the engine/ Carbs
Hope This helps.
Oh and follow Serrans advice he is the Guru on these engines.

[davidvincent]

Hi all, just to report back...

Turns out the issue was down to the left carb having a warn/failing needle valve, letting in too much fuel and causing the poor idling and ultimately stalling.

Huge thanks to Mike (BigHerb) for both diagnosing and fixing the problem - drove all day today with no issues

Dave.