I have my own opinion on this but I want to see if I am overly cautious. I have a forty horsepower mercury on a sixteen foot aluminum boat. When I first crank up in the morning I let it idle for a few minutes and then run it slow slow slow for about five before going all out. I was told once that letting it warm up for at least five minutes is very important. Now, let's say I make a twenty-thirty minute run to a spot, and then use only the trolling motor for an hour and a half. Is it necessary to let it warm up again, or can I just turn it on and go. I've always let it warm up for a minute or two. Am I worrying too much? Thanks in advance, JPB

I don't have a ton of experience with 2 stroke boat motors but I have with many other 2 strokes as well as 4 strokes.  The purpose for warming up is usually to get the oil flowing well throughout before going full bore.  A few minutes is plenty of time for that.  Now that being said, a few minutes may not be enought time to completely warm it up and some finicky motors will run better when they are warm.  .

I had a boat equipped about the same. I would let it warm up a little on the initial start up of the day but it is not necessary after that. It would have to be a bone chilling day and it would have to sit for quite some time before it would cool to a point of needing to be warmed up again. Besides a two stroke has gas and oil being sent thru the system at the exact same time which differs from a four stroke. It will never hurt it to warm up no matter the conditions as long as it never loads up on you and wants to die or run sluggish until that gas oil mix is burned off. I say if this is not the case do what ever makes you feel comfortable. My .02 worth.

I agree with your caution.I dont have a ton of experience working on outboards but all the research Ihave done says the most abuse engines take is the folks dont let them warm up before letting them rip.

Thanks for all the insight. I just want to be sure I treat the motor right--won't be able to afford another one for a while. Cheers, JPB