I have a couple problems with my motor. My water pressure is only 8 psi at wot. Can't run it long like that it want to get hot I think starts running bad. I have installed new water pump and housing Also new thermostats and pressure relief valves. Motor is not to high. I have even tryed running it as low as it will go. Did not change anything. Motor was so low exhaust ports was under water idling. Idk what else to do on it. At idle it is running normal pressure. 2 to 4 psi. My next problem is between 1700 and 2000 rpms my tach quits. Once my rpms drop below it starts to work again. Any help welcomed.