My water pressure was reading pretty low so I installed a new water pump kit,while installing the new kit I noticed the water pump housing was in bad shape, so I replace it too. I also replaced both t-stats. While the lower unit was off and the t-stats out, I put the water hose up to the tube the water pump hooks into in the lower unit to flush out any thing that might be in the system all went well water came out of the heads were t-stats were and the connection for the water pressure guage hose. I also checked the pop it valve every thing appeared ok there too. Well here's the problem after all was put back together I cranked it up with muffs and got instant water pressure for about 45 seconds then went to 0 I though maybe one of the o rings in the pump maybe moved out of position so I take the lower unit off and check it out every thing appears fine, so I restart and instant pressure again but only for about 30 seconds then back to 0 any ideas. The heads felt pretty hot but not hot enough that I couldn't keep my hand on them. Thanks for the help. 1996 Yamaha 200hp
