i had the same problem. i pulled off the intake screen on the filter and found it stuffed with debris. i cleaned it and replaced it. nothing. i undid the strainer from the through valve in the hull and i found a twig blocking the water inlet. i pull out the twig and the water came out about a foot in the air so i had good opening again. i recrew on the intake filter and then i had water coming out the exhaust. go for the simple things first.