2016 Suzuki 150 SS

[Ranger07]

I have a friend you has a Suzuki 140hp. When you start it is running at an idle. When I start my 150SS it revs way up, then idles down and about 1/4th of the time dies when it idles down. Is that normal for them to rev up like that every time you start them? I took it in for the 20 hour maintenance and they said they had to replace a piece that was not functioning correctly and that is why it would idle down and die but apparently that wasn't the problem because it is still doing it.
Also when I had 5 hours on the motor during break-in I started it and so much smoke poured out of it you could hardly see the motor! Now it has about 30 hours and every once in awhile I see a small amout of smoke in the air when I start it. The dealer told me not to worry about it because it was under a 6 year warranty but it cost me a lot of money and I am worried about this four stroke smoking. Has anyone else experienced any of this with there Suzuki? Thanks

[Moonlighter]

It should not rev excessively when started from cold. The part that has greatest influence on starting and idle speed is the IAC valve.

The normal thing when a cold engine starts is for it to idle a bit faster then settle at about 650rpm. Basically the ECU is giving it some extra fuel (like a choke on carby engines does) when it's cold.

Talk to your dealer again and explain the problem still exists. Take a video on your phone and show them. I would say there is still possibly an IAC problem, it should be replaced, not cleaned, if it isn't working, as a faulty IAC can damage the ECU. When replaced it has to be reset so the idle speed is correct. Dealer should know this and do it.

The smoke issue is separate.

Question: when you store the boat, how is the engine trimmed? Is it dropped down so it is vertical or is it left trimmed up on an angle? If left trimmed up, this can cause oil to accumulate and then burn off big time when started!

A small puff on first start when cold is not an issue, mine did this when new, it will settle down when the engine is fully run in, say 100hrs.

[Harper]

The immedaite rev to 1800-2000 RPM the back down to stall is typical of low voltage to the ECM. White wire to the ECM relay, or batteries not topped off, or any other battery connector or cable problem that could cause a voltage drop when starting. Check your whole battery cable setup. It always acts like a bad IAC, but it's usually the voltage problem.

Unless you're now showing a large consumption of oil, having to top off often, I wouldn't worry too much about an occasional puff of smoke on startup.