Opinions on Suzuki 9.9 EFI engines

thatone123

Banned
Joined
Mar 7, 2009
Messages
707
They are heavy built for their size and fairly reliable. I have just acquired one that has moderate use and still the oil injection works and if it had been proper maintenance done, would not have any problems. Keeping the motor clean and free of oil and gas will go a long way to prevent electrical problems. This is a carb model, so don't know that much about the EFI.
 

Durango318

Seaman
Joined
Jun 12, 2010
Messages
68
You will love the Suzuki DF9.9
Some things to know. The engine is EXTREMELY efficient and the lightest in it's class. It is quiet at neutral and 2/3ds power levels and up. Some people object to a mild gear case whine at low and trolling speeds it doesn't bother me but then again I didn't notice it until it was written about and that I'm usually at WOT except at warm up and 5 mph zones. If your boat is rated for it, go for the bigger engine. The 9.9, 15 and 20 HP engines are exactly except for the ECU (engine control unit) and the decal on the engine cover. All the other internals, gear ratio and prop are the same. The ECU controls the power level. So in other words the 9.9 isn't working very hard. The stock prop will over rev on the 20 hp unless you are using it as a kicker but it's good for break-in. Install an in-line water separator on the transom like the Sierra they sell at Walmart, the one on the motor needs all the help it can get. After the break-in interval is over, the power output rises. If you are running the engine deep like most RIB's (cavitation plate well below the boats bottom) you may see twin rooster tails. Some units have a 3/16-1/4" wide blunt edge on the front of the gear case. If you round off the edges, the tails go away. Use both the engine's mounting clamp screw AND the bolts provided. Yes I know it's a pain, but if you cross a wake and counter the forces to control the boat you can torque the motor right off the transom using the clamps alone! (Not just this brand of outboard) This is even more important if you mounted the motor high on the transom. You may have some tiller torque at high speed. Don't use the heading hold lever to control this because it vibrates the tiller handle. Use the tiller friction bolt but don't over do it. If you need more control you can make a wedge of "JB weld steel"on the right side of the skeg. Just remove a 1- 1/4 wide strip of paint from the gear case to the bottom of the skeg and build a wedge of JB weld to about 1/4" thick at the trailing edge. When done the trailing edge should be blunt/flat when veiwed from behind and even with the motor's skeg. Don't round the trailing edges. Sand off or build up how much trim you need and paint. The trim could cost you about 1/2 mph but what you gain in safety and fatigue is worth it. I didn't need them, but I highly recommend "Smart tabs" if you have slow plane or porpoising. Several guys have ditched the "Dolifns" and installed the tabs and are thrilled. I know it's a lot info, but when you have things fine tuned it's a lot nicer.
 

mla2ofus

Chief Petty Officer
Joined
Dec 30, 2008
Messages
571
Thanks, durango!! If I buy the 9.9 it will be on our 12' Livingson which is a displacement hull so no speed needed. Our present motor has a short chain bolted to it and the transom so it can't take a trip to Davy's locker. Our old one is a '54 15HP 'Rude that starts easy and trolls all day without missing a beat. I'm getting up in the years and think electric start might be nice to have!! I just have to decide if I want to spend that much to just push a button.
Mike
 

Durango318

Seaman
Joined
Jun 12, 2010
Messages
68
Well with a healthy 9.9 that Livingston may not just run in displacement mode! There's a lot of guys that are hauling in those things. Look at Youtube. I had a 10 footer two years ago with an Air cooled Gamefisher on it. My son discovered that when he tilted the engine back a bit that he could make good progress through a river chocked up with water hyacinths. The weeds slid down and under the skeg and the prop didn't care if it used water or weed for propulsion. That little thing was the only thing moving on the river!
 

Durango318

Seaman
Joined
Jun 12, 2010
Messages
68
By the way,I have the Suzuki 20DF on a 12' RIB and it does 31 mph two way average GPS verified. I get to places all over the California delta very quickly, cheaply and sometimes even quicker than I can dive there.
 
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