Douglas MkV carburettors

[Pallijen15]

Hi, the right side carburettor does not have any effect no matter how I try to adjust it. If I put my hand over the bellmouth it makes no difference whereas the left side carburettor will stop the engine immediately if I do the same. Left side spark plug was a little black and dry sooty, the right side was black and oily. Swapped plugs over, no difference between carburettors. Is it okay to have the needle on a different notch from the other? Would this help?  Also, gasses emitted from exhaust was hotter on right side than the left. Of maybe the carburettor is just knackered and needs a full reconditioning. Any help greatly appreciated. Paul Jensen

[EW-Ron]

Does it seem to be running as a twin ?! 
If you tug on the throttle cable on the rhs, can you make the engine speed rise - at all ?

Sounds like you need to do an engine compression test.
If the right side is mechanically poor/worn/knackered, it may not be good .....

If the jets in the rhs carb are all corroded up/blocked/filled with gunge, you may get this too.
Some investigation required !

[Pallijen15]

Hi Ron, yes, the engine speed operates as normal when I use the throttle/pull the  cable/lift the slide with my finger in the bellmouth. Carburettors are both clean. Might it help dropping the needle a notch?

[yosemite]

I know it would make adjustment  nearly impossible but have you thought about swapping carbs over from left to right temporarily to see if the problem migrates with the carb, this would help confirm wether the problem is with the carb or if it has another cause.

[Pallijen15]

No but I could adjust them first then swap over. I'll have a look first and see what position the needles are at in their slides. Thanks

[Jonathan Hewitt]

Surely if the engine stops when the Lh cylinder is fully choked by hand the Rh cylinder cannot be working at all ,or did you mean to say that the Lh cylinder is the hottest ? just a thought
Jonathan

[Pallijen15]

Hi Jonathan, yes, I'll check that again next week, must have got that the wrong way round. Thanks