318 smoking and knocking one day fine the next

My first season with this 30&#

My first season with this 30' 1973 silverton with twin 318's.

Saturday I took it for a fairly long cruise - about 45 miles total. At the end of that the starboard motor was having trouble restarting and it was smoking pretty bad and also knocking. I thought the motor was blown.

I let it rest for the evening and when I went back on Sunday morning - it started fine. No smoke and no knocking. I did not take it out and get it hot.

Any ideas as to what would cause this? I watched the temp gauge and it was not overheating on Saturday. Oil level was fine both days.

- David

"I assume this is a raw water

"I assume this is a raw water cooled motor? if so my best guess is that you sucked a rag or plastic bag over the water intake, which cut off water to the motor for a brief period--and it doesn't take long.

Note: Temp gages don't show the rapid increase that happens because they work differently when not immersed!

If my theory is correct, then you dodged a howitzer! My 50 hour old motor spun a bearing when this happened to it. And you're probably going to be okay.

Jeff"

hmmm... i don't know abou

hmmm... i don't know about that. I have been having a lot of minor problems whith the starboard. I'm just afraid when I take it out next time I will have trouble.

As for the water - it has both a place for coolant input and I believe it uses raw water with impellers. Not sure. I guess I'll take a photo so someone here can help me identify what I have.

"If it has a coolant tank with

"If it has a coolant tank with a pressure cap, then it's a fresh water cooled system. They will also overheat if the raw water is cut off, but the temp gage will go up as it does.

Might still have a real problem, sorry.

Jeff"