tiktock

thanks guys for the suggestions........ "jongurley" I'm going to go through your post but had a few thoughts regarding your suggestion. i checked the red and black ignition wires with a continuity meter and everything seemed ok.
i wanted to try to solder a tube to the diaphragm and put it in the box... to do that, do i need to remove the rubber diaphragm from the metal plate? if i leave the rubber and solder the tube to the metal, will the rubber not get damaged?
also, does the balsa box have to be completely closed? i fly with out a cowl so, i don't know if the diaphragm mod will work.

blkbird68...... i checked the tube and it seems to be ok, though i remember there used to be very little fuel around that area and could that be there because of a bad fit?
i will go and tie a wire around both the tube ends.

anyway, could the weather have something to do with the rpms? when i said it was " hot and dry " that was a few months ago and now we have the monsoons and it's very humid, could that have something to do with the rpm loss?