I am working on my '98 wr400. I have no AP squirt. I have checked all of the passages and are clear, with the exception of the float bowl to AP passage. I assume that it has a check valve in it: 1. because it would need to flow one-way from the pump to work and 2. there is a brass plug. So here's the question; is the valve normally open and it closes from diaphragm pressure or is it closed and the diaphragm pulls fuel in?
The diaphragm pulling the fuel seems unlikely, but if I fill the bowl with carb cleaner it does not run out. If I plug the port with the tube of the carb cleaner can and spray it sprays out.
Does anyone have any experience with this?
Edited by tcmII, August 08, 2013 - 06:18 AM.