Re: JOHNSON 15
The water flow circuit is roughly as follows:<br /><br />Water is pulled in by the pump (impeller) and pushed up the copper tube, which should be sealed top and bottom. It then goes round the powerhead, with some going out of the telltale, through the cylinder head and cover, where its flow is regulated by the tstat. At this point it's hot, and it then flows back down the lower unit outside the copper tube and around the exhaust tube - exiting through the vent holes above the AV plate. <br /><br />If you have water coming out of these vent holes, then it's circulating. But - there could be a blockage within the power head, causing the overheat problem.<br /><br />It seems to me though, that you may not - as you've said - have enough flow. The telltale should show a strong flow. If you can hold the tube out sideways, it should make a good arc through the air, not just dribble straight down.<br /><br />If you can run the motor on muffs, the above flow pattern should show up. If it runs on muffs without overheating, then that tells you you've got a water pump problem.<br /><br />Hope this helps.