---

Yes, I'd definitely try trolling with your main motor first - assuming your 7.4 was carbed, you're going to find a massive difference. You'd hate to mess up the transom of that nice, new 190 if you don't need to - and it's likely to drop your resale value too, if that matters.

From Whaler's website, you'll be using at most 1/2 gallon per hour at trolling speeds - almost not worth thinking about.

Tim