Solex choke flaps

[cumbriankeith]

My 2 litre Aircooled CU engine (with stock Solexes - NOS 30k miles ago)was running a bit rough over the last month or so - underpowered and popping at times. It got worse and I traced the problem to a leaking/perished rubber elbow on the right hand inlet manifold brake vacuum takeoff. I did a quick and dirty repair with a bit of plastic hose which lasted a fair time but then melted (yes - I know I should have got the right replacement part in the first place!) - providing the same symptoms again. Even after I refixed the problem the engine would start from cold nicely but then be way down on power once warm.
On taking the aircleaner off I saw that the choke flap on the right hand carb was both mishapen and jammed on, presumably due to a backfire when the induction side was leaking. A careful tap has freed it up so that it will now come off once warm, but it is still out of kilter due to being shaped like a double curved Pringle! I have an "old" pair of carbs from which I could perhaps strip out a choke flap and replace the bent one - is this a tricky job? Will things go ping or out of adjustment with dismantling?
I'm generally pretty good with fiddly jobs but don't want to wreck it!
Any top tips someone?

[steve8090]

Procedure.
Remove carb and drain of fuel, remove return spring and electric choke, undo 5 screws that hold the carb together and split, watch out for the float in the bottom half, turn the top upside down and remove the two screws that hold the choke flap in, be carefull ofthe small shims either side of the flap and make sure they go back, pull out the choke flap, replace with new one (there is a dot on one side, this faces upwars when the choke is closed) and refit the screws, note the screws will have been peened over slightly and will need to be dressed to go back correctly, do not overtighten as they are easily stripped, check the gasket between the carbs and replace if torn, re-assemble in reverse order (haynes classic).
If in doubt see my website and send me a set of serviceable carbs, I will treat them to a complete refurbishment and seal the shafts, you get them back as good as new.

[cumbriankeith]

Steve
Thanks for reply - see other thread

[mgm]

Well I made a nice little widget to measure the accelerator pump quantities on my Stock Twin Solex's. Said gizmo consisted of a bent piece of copper tube with a silicon manifold (to connect to the acc pump outlet) and a graduated vertical glass tube. This was marked with the Haynes min and max quantities and the mid-way point.

The Haynes manual states to screw the adjustment in-clockwise to increase the pump flow. What rubbish, screwing in the adjustment makes the stroke of the diaphragm actuator shorter and hence the volume of fuel pumped smaller, as proved by the measuring gizmo. Surely there is a Hay*** "cock"-up thread somewhere??

Just thought I'd share that jem .

.