Re: rpm
Hi,<br />Specifications for Your DF50 is available at Suzuki US website:<br />
http://suzukimarine.com/sr04/df5040/features_and_specs.php <br /><br />As You can read there the recommended RPM range at full throttle is between 5900-6500 RPM.<br />Although the specifications is for a 2004/2005 DF50 I'm almost sure it apply to a 1999 DF50 as well since this outboard has been the same to the best of my knowledge since it first came out on the market in 1999. The RPM range 5900-6500 is rather high range since usually around 5500 RPM is in most case the range that apply to many other standard 4- and 2-stroke outboards. You have to look in an Owner's manual to know the "maximum output RPM". For example I have a Yamaha F115 4-stroke that accept a full trottle RPM range from 5000 to 6000 with a maximum output at 5500 RPM. With my prop I get excatly 5500 RPM at full trottle so my boat/engine/prop combination is rather optimal.<br />In Your case I would probably aim at 6400-6500 RPM at full throttle and
economical cruise RPM at something like 5000 RPM (see testresults below).<br />I have here in front of me a test of six 50 hp outboards: Honda BF50, Johnson J50, Mercury F50, Suzuki DF50 and Yamaha F50. The plus side with Suzuki DF50 in this test is that it is very quiet:<br />Full RPM: 87 decibel<br />Minus 500 RPM: 85<br />Minus 1000 RPM: 83<br />Minus 1500 RPM: 81<br />Minus 2000 RPM: 80<br />At 5 knots: 68<br />At all tested RPM the Suzuki DF50 was the most quiet.<br /><br />If You want to have some numbers to help run it economical, here is what the test showed for DF50:<br /><br />a) Fuel consumption in liter/hour:<br />Full RPM (in test 6500 RPM): 17,2<br />Minus 500 RPM: 15,4<br />Minus 1000 RPM: 13,2<br />Minus 1500 RPM: 9,8<br />Minus 2000 RPM: 8,6<br />At 5 knots: 1,8<br /><br />b) Fuel consumption in liter/nautical mile:<br />Full RPM (in test 6500 RPM): 0,54<br />Minus 500 RPM: 0,52<br />Minus 1000 RPM: 0,51<br />Minus 1500 RPM: 0,42<br />Minus 2000 RPM: 0,43<br /><br />Test boat was a Buster L aluminium boat, 330 Kg empty weight without outboard, 4,95 x 1,97 meter with 18 deg V-hull at transom. A very popular boat in our country for 40-60 hp outboards.<br />If You want to know the speed that was achived with this boat and DF50 it was this:<br />Full RPM (in test 6500 RPM): 31,8 knots<br />Minus 500 RPM: 29,5<br />Minus 1000 RPM: 26,0<br />Minus 1500 RPM: 23,6<br />Minus 2000 RPM: 20,0<br /><br />Good luck and buy an Owner's manual from a Suzuki dealer or order online from for example<br />
http://store.brownspoint.com <br />If You want/need a Service manual it is also available but it is a little more expensive.<br /><br />By the way, You may want to have a look at some of the Suzuki videos that give some advice how to use and for maintenance of Suzuki outboards:<br />
http://suzukimarine.com/videos/maintenance.php <br /><br /><br />/Bo
