firstly carby cleaners and ethanol sprays dont do the plastic carby any good and often eat away at them like acetone does plastic this is because the sprays are designed to dissolve varnished fuel and plastic isn't much better since it is too a petroleum product.
it sounds as if you may have issues with you seals. if they are wet and have a moist ring around the outside thats sometimes a good indication they have gone. another way to tell is to pour a bit of petrol down the spark plug hole and see if it leaks out the bottom seal. you can tip the mower over to test the top one in the same fashion but be careful you dont get too much petrol in the coil as it may eat away at it.the seals only cost about $5 from my mower shop and are easy to install after you pop the blade boss off.be careful when buying the seals as there are big and small ones. from memory , but dont hold me to it the later ones (such as yours) used a smaller seal than early ones. when i say smaller we are referring to outside diameter.
when you assembled the carby did you set the poppet valve to a certain mixture (done by turning the corresponding letter towards the venturi hole) or just pop it in there. in the past Ive had instances where even though the valve isn't set properly it runs well on one unit but not on another. the valve should be set so that the "C" lines up with the venturi from memory but i may be wrong.
Joe was right in what he said because if you look at the air filter housing the diameter of the tube is reduced to about 1/2 inch which is so the engine cant suck too much air and therefore helps create a vacuum in the manifold to activate the decompresser and diaphragm in the carby.
see how you go with the seals first
regards jay
Last edited by mowernut; 07/06/10 12:39 PM.
