My 140 RX has suddenly become cantankerous . After cleaning the spray bar and needle valve housing with compressed air followed by gently syringing fuel through the pump inlet port and out the outlet port , I can get it to run with the low speed mixture set on the rich side. (Didn't need to run it that way before.)I suspect a fine particle is lodged internally in the pump , despite straining my fuel and filtering it from container to tank as well as inline. OS warns owners not to disassemble the pump(warranty issue?) , but I'm leaning that way and wonder if others have successfully disassembled theirs for the same reason and experienced success,leaks or other complications.. The engine has about 25 flights and is still under warranty , but I hate the idea of giving it up for several weeks during prime flying season.And a new pump is $$$.

If you haven't done it already, you can check the pump's action to some extent by disconnecting the fuel-supply line at the carb and turning the engine over with a starter.
You should get a fairly vigorous uninterrupted stream of fuel if all is well.
If you wish to dismantle the pump, it's quite a good idea to replace each of the four ?2mm bolts which go right through it from front to back, in turn, with a suitable length of wire,about 3" long,with a right-angle bend near the end of each wire.
Then you can "open" the pump out, with the components spread out along the wires, rather like a kebab, without too much risk of getting them out of order/alignment.
Edited to add:
If it's still the original rear bearing, even that new, the most likely material to block the pump is probably rust particles....

Believe it or not, it could be your rear bearing dragging. the stock bearing has been know to last as few as 30 flights. The symptoms will show up as unusual needle settings and poor acceleration. My first stock bearing lasted maybe 50 flights before I changed it out. Every other 1.40RX that I bought, I threw away the stock bearing and replaced it with the rear bearing from the 1.40RX EFI which is stainless and will last hundreds of flights. I never bothered to even run it with the stock bearing. Before you do surgery on the pump, I would change the bearing.

Thanks for the replies. My cleaning efforts seem to have paid off- - three perfect runs today in hot & humid conditions and I didn't have to disassemble the pump. BTW, I replaced the stock bearing with the one from the OS140RX FI before I ever ran the engine .

Good to hear you fixed it. That is probably the only maintenance you will need to do for a few hundred flights now - except maybe a new glow plug or 2