Page 1 of 1

Four stroke motor size

Posted: Sun Apr 05, 2009 10:27 am
by Pete
Those of you who have been following my boat restoration know I am trying to have it in the water for Memorial day weekend. One of the big obstaclals was the motor, as I did not have one. Any ways I broke down and bought a bran new Nissan 9.8 hp four stroke with the extra long shaft and electic start. Now first let me say that I am not a big fan of the 4-stroke. When it comes to raw power, relibality, and weight 2 strokes are head and shoulders above the four strokes. But they Pullute and are nosey. Anyways back to the 9.8 Nissan. This thing is huge. Its every bit as big as my old 25 hp Evenrude. It flexes the motor mount and towing with it on is out of the question.

Pete

Re: Four stroke motor size

Posted: Mon Apr 06, 2009 6:27 am
by Pete
Any ideas of how fast a V222 will motor with a 10 hp motor. I am mapping out my Memoral Day cruse and it looks like about 50 miles.

Re: Four stroke motor size

Posted: Mon Apr 06, 2009 6:53 am
by Hamin' X
Max speed for a displacement hull that is 20 Ft on waterline is 6 kts, or about 7 mph. A 10 hp engine should drive you at hull speed with no problem. Actual speed over ground will depend upon many factors such as wind and current.

~Rich

Re: Four stroke motor size

Posted: Mon Apr 06, 2009 7:16 am
by CMikey
I have the Nissan 8hp /Electric start on my Mac 25 and it will push my boat at hull speed using 3/4 gas. I put it on the motor mount bracket that was on the boat when I got it and it has so much thrust that even though the weight is only 86 lbs. it still causes the mount to flex. I am ordering a bracket designed for 4 strokes. Even though I have a safty line tied to my stern rail I don't want to take any chances on dunking my new $ 1850.00 motor in the salt water.

Re: Four stroke motor size

Posted: Mon Apr 06, 2009 11:21 am
by Pete
My plan is to go from the Castle hayne Ramp on the NE Cape Fear River to Masonboro Inlet. At 7 mph it would take about 7 hours to make the trip down the river. Should make for a nice trip. I used google earth to caculate milage. If I time it right I would have the tide working with me.

Re: Four stroke motor size

Posted: Mon Apr 06, 2009 1:42 pm
by Night Sailor
When I had a 1974 V222, I used a 7 hp 2 stroke Mercury with standard prop, but it pushed her to 7mph in calm lake water with a normal cargo and crew of three. IF I recall correctly, that was WOT.

Re: Four stroke motor size

Posted: Tue Apr 07, 2009 9:30 am
by Pete
Any ideas of Gas milage for the 9.8 hp 4 stroke. I wonder how much fuel I would need to make a 50 mile trip.

Re: Four stroke motor size

Posted: Tue Apr 07, 2009 8:17 pm
by CMikey
Any ideas of Gas milage for the 9.8 hp 4 stroke. I wonder how much fuel I would need to make a 50 mile trip.
I motor sailed in light winds with my 8hp Nissan from Naples to Marathon, Fl. which is approx. 92 miles adveraging 4.5 knots and used 4 gals of gas. I think if you had two 3 gal. or one 6 gal. tank that you would have planty of fuel to test drive her and get a feel for what fuel you would require based on the conditions of the day. Don't forget that the motor will require 10 hours to break-in and you won't want to worry much about gas mileage until after the break-in period.

Re: Four stroke motor size

Posted: Wed Apr 08, 2009 3:21 pm
by Pete
I wonder if I can do the break in all in one day?

Re: Four stroke motor size

Posted: Wed Apr 08, 2009 5:34 pm
by CMikey
The above mentioned trip from Naples to Marathon, Fl. started at 6:30am on Saturday and ended at 8:30am on Sunday for a total of 26 hours. That makes for a very long day.

Re: Four stroke motor size

Posted: Fri Apr 17, 2009 9:21 am
by Pete
92 miles in 26 hours which is about 3.5 mph. Did sail most of the way or motor? And was the current favorable or not much. I am looking at half the distance and hoping to do it in a quarter of the time. If I time it right i would have the tides helping me in both directions.

Re: Four stroke motor size

Posted: Tue May 05, 2009 1:43 am
by Kelly Hanson East
That fuel estimate above is misleading - Im guessing CMikey had a good draw while motor sailing

Manufacturers data for Nissan 9HP motor shows about 1 gallon per hour fuel consumption at WOT for the 9.8 HP. At cruising speed plan on 3/4 that consumption

So I would plan on 8 hours cruising and 6 gallons of fuel consumed. Seamanship would necessitate your carrying a 6 gallon and a 3 gallon tank, and knowledge of where to get fuel on the back end of the trip.