# Suzuki DF6: sometimes down on power



## MattGent (Nov 12, 2009)

I bought a Df6 new in 2019 as a kicker/get home for my bigger boat. Have been playing with it on small boats as well.
It always starts up and runs easy, no stumbling or anything. Always on rec90, and so far only have used the onboard tank.

On a friend’s microskiff, sometimes it runs 17-18mph solo and sometimes it runs 14. This is on GPS and independent of current.

On my little runabout it was struggling to plane 2 adults, which maybe wasn’t an unexpected result. Except for right in the middle of one trip it planed us right off and we ran along quickly for a few hundred yards before it slowed 5-7mph and back into a plow. It ran 18 with me solo on one occasion, and planes my son and I no issue. 

Doesn’t seem any rhyme or reason for a “fast” day or a slow one. I don’t have a ton of back2back data as the usage is sparse and the boat is still in rebuild. But it’s clear from the microskiff that performance is on or off.

Any ideas what to look at? I do plan to try an external tank. I have a little digi-tach to measure rpm as well.


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## MattGent (Nov 12, 2009)

pics because posts are better with pics

micro/flounder skiff:









flivver rebuild wip:


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## jay.bush1434 (Dec 27, 2014)

I'm going to hazard a guess and say that there isn't anything wrong with the motor. I think you are right on the cusp of that not being enough motor. Maybe you get a push from a wave while running downwind and you jump up on top and go running along just fine and then other times, not so much. Before I say, "final answer" I would like to hear what the rpms are doing, is it totally random, or does it always run good and plane out easily when solo or running with your boy?


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## Refischer (Mar 21, 2019)

You could also try a hole shot in shallow water compared to deeper water. It should plane off quicker in shallow water.


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## Viking1 (May 23, 2010)

I've got a 2018 6 HP Suzuki. I see very similar performance with mine. On my 12' boat with just me and fishing gear my max speed is 13.5 MPH. If I add another person top speed drops to 8 to 9 MPH. In my personal opinion this is a small motor and its never going to be a race horse. Overall I am happy with the motor.


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## MattGent (Nov 12, 2009)

Yeah I get its not for racing. I picked the engine for size & weight for use as a kicker. I'd just like it to consistently perform at its best. Eventually I'll pick up a bigger engine for the flivver for real fun.

I expected the flivver to be marginal with two adults. I've tried the smallest prop I can get, and it just plows along right on the verge of planing. Except that one time it planed off directly and took off running at least 5mph faster than plowing speed. Then it slowed on its own, clearly dropping a few hundred rpm and back to plowing. On this occasion we were down-wind in a little chop. I tried to repeat it but it wouldn't pop back up.

The owner/builder of the flounder skiff (I borrow his boat, he borrows my motor) reported the same thing. Some days it is measurably faster than others. That boat is super light and narrow, we didn't expect 18mph from a 6hp. It has no discernable bow lift, just transitions to planing/semi-planing. I have run this boat with 4 adults and it will go 10-12mph in that state.

Clearly I need more data. Usage has been sporadic, on different boats and different loading conditions. Other than a fuel supply issue I couldn't think of another reason why the power would change. I'll gather more info and report back.


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## MattGent (Nov 12, 2009)




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