Re: 68 Johnson 33hp
No problem!<br /><br />Do you have the water level up to the impeller housing when you're testing? If that's not it, I'm afraid the next thing is to pull the lower unit and try to find what's wrong. If you can't easily blow up through the water tube, then it's blocked somewhere. You can attach the cut-off end of a garden hose to the tube, held on with a hose clamp to try to blow any obstruction through if it's blocked.<br />Otherwise, is it possible that the impeller key fell out of place? How about having the impeller vanes pointed backwards (they'll normally flip right back over when you start the engine, unless the impeller has been lubed)?<br />The cooling system is pretty simple - not much to go wrong and no really narrow passages. It takes a few seconds for the block to fill up before it starts gushing too.
<br />I think DHPMarine is thinking of the 40hps. The early '50s 25hp, 30hp, and some 35hp (not super quiets) had no thermostat. The '60s 28hp and 33hp didn't either. They were based on the 30hp and 35hp (not super quiet) engines.
