I have run a 1986 15 hp 2-stroke Yamaha on my 14 ft starcraft for years. It still runs good but my kids , me, and fishing partners get bigger every year. In Canada Some days we run 20 miles exploring fishing spots and the 15 hp could only get about 12 mph with 3 in the boat. So this spring I bought a 20 hp 4-stroke Suzuki. It fixed the speed issue but it came with a small 3 gallon tank because the 4-stroke supposedly are more efficient. I have only had it out a couple of times(7 hours) but it seems to take about the same amount of gas as the 2 stroke. Will this improve as it breaks in? My thought is no and to make the 20 mile run in Canada and get back to camp I will have to get a bigger tank. I always hear about the 4 stroke being more efficient but I think these small 2 strokes used so little gas the improvement is hardly noticeable. And the step up in hp also adds to the formula. We did make a 17 mile run on the river and then back so I did get 35 miles but I had less than a gallon left when we got back to the boat landing. Love the 4 stroke and it is only 20 lbs heavier than the 2 stroke which I thought would be offset with about 20 lbs less in gas.
Boats & Motors
15 hp 2 stroke vs 20 hp 4 stroke
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With 2 guys I went from 19 mph to 23 mph and with 3 guys I went from 10-12 mph to 19mph. So yes it fixed my speed issue. The 15 hp just couldn’t get on plane with 3 guys. Bigger tank is on order. I kept the small tanks because I usually don’t go that far and will use that most of the time. Yeah these motors under 25 just sip the gas, 6 gallons will probably last me all summer in Wis.
I was just figuring if you can go 35 miles on a little over 2 gallons in a river. That's approximately 14 to 17 mpg. That's outstanding gas mileage. My 150 Yamaha 4 stroke gets 3 to 4 miles per gallon at best cruise. Get a 6 gallon tank, keep the 3 as backup. If you can get 12 mpg with a bigger load. With 9 gallons, that's 108 miles. Enjoy your new motor. You did not mention if you gained any top end speed?
Your gas mileage with your new 20 hp is fine. Get a 6 gallon tank. Keep the 3 gallon as a boat back up. Store the 3 gallon up front until needed. In Canada, keep a pair of oars tucked away for emergency. If you take your lower unit out on a rock. All the gas in the world won't help you. Oars will always get you home. As your family gets older and larger, the 14 footer probably won't cut the mustard. 3 adult size folks need a 16.5 to 17.5 footer to fish all day for a week in Canada comfortably.
if I drive 20 miles I don't drop anchor and sit in one spot all day. After the 20 mile drive we still cruise around that area throughout the day. I've done the math and it would be cutting it close. Unless the motor gets more efficient the 3 gallon tank is not enough. In Canada there are no cell towers and we rarely see other boats where we go. If you run out of gas you are on your own to figure a way out of the wilderness. This is my first 4 stroke and my main question was will it get more efficient as it breaks in? My thought was no but thought I would ask others that had smaller 4 strokes.
I had a 25 hp 2 stroke 1999 Mercury on a 14’ Jon boat. That motor burnt a piston and was junk. I replaced it with a 25 hp 2020 Mercury 4 stroke. I get more than double the run time from the 4 stroke. It is heavier than the 2 stroke to the point I need to place the 6 gallon fuel tank mid boat rather than between the back bench seat and the transom. It gets on plane just as quick as the 2 stroke, runs so much smoother and quieter as well as starts in an instant. The 1999 Mercury was from the era Mercury tried not putting sleeves in the block but rather coated the block bore with a wear lay of Mercosil which was a failure waiting to happen which it eventually did.
Strange you do not use less gas. I ran a 25 horse johnson 2 stroke for years on a used 14' Lund boat I bought. Then switched to an electric start
20 horse mercury three years ago due to a bad shoulder (could no longer pull starter cord). First season I noticed how much less fuel I was using.
I normally fish by myself on small lakes and do not run it long on full speed. Seems to use about 1/3 less fuel per year based on what I was using with the old 2 stroke.
However, I would not use a 3 gallon can fishing big bodies of water! I have a 3 gallon can for an old 6 horse I use on a small boat for a lake that has no boat landing. But for my 14' Lund I have a 6 gallon. Fishing in Canada on big water? I would put 2 six gallon tanks in the back of the boat. Never want to run out when fishing big water. "Be prepared" is still a good motto from the boy scouts.
20 horse mercury three years ago due to a bad shoulder (could no longer pull starter cord). First season I noticed how much less fuel I was using.
I normally fish by myself on small lakes and do not run it long on full speed. Seems to use about 1/3 less fuel per year based on what I was using with the old 2 stroke.
However, I would not use a 3 gallon can fishing big bodies of water! I have a 3 gallon can for an old 6 horse I use on a small boat for a lake that has no boat landing. But for my 14' Lund I have a 6 gallon. Fishing in Canada on big water? I would put 2 six gallon tanks in the back of the boat. Never want to run out when fishing big water. "Be prepared" is still a good motto from the boy scouts.
Displaying 1 to 9 of 9 posts
