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DF90a wont start

douglasdm

New member
Hi. I am a new member and a first time boat owner.

I bought a pontoon boat over the summer. It came with a 2011 Suzuki DF90a engine. We used the boat almost every day for a month with no issues.

We noticed we had water in our lower unit and after 6 weeks it took to get the parts and special tools we needed to replace the seals we took it out and had a nice day on the water.

The following weekend, we cranked the engine before we hooked up the truck and after idling for a minute or so, the revs dropped and then it died. It sounded like it ran out of gas. Now, when we turn the engine over, it hits on a cylinder or two and then just turns over until we stop cranking it.

Like I said earlier, I am a newb at boats and outboards as well as fuel injection.

What are some of the simple things I am probably overlooking. In my experience, most issues with cars and motorcycles wind up being simple things but it takes experience to know where to look.

Thanks in advance!
 
Can you hear the high pressure fuel pump with the key on, not running? Should hear the pump run for 3-4 seconds as soon as you turn the key to on. Condition of fuel filter? Pick up any water in the fuel? Low pressure fuel pump moving fuel into the VST? You mention no alarms so I assume none were triggered.
 
Can you hear the high pressure fuel pump with the key on, not running? Should hear the pump run for 3-4 seconds as soon as you turn the key to on. Condition of fuel filter? Pick up any water in the fuel? Low pressure fuel pump moving fuel into the VST? You mention no alarms so I assume none were triggered.

Thanks for your response.

New fuel filter.

Fresh gas in the tank.

New fuel water separator.

I can hear a "pressurizing" sound coming from behind the intake manifold when I switch on the key, that would be the high pressure pump from what I understand.

The low pressure pump makes no sound. From the looks of the low pressure pump, it looks like its mechanical. I don't see any wires going to it and its bolted directly to the head.

Which alarms would I be listening for?

I have heard that there is a port like an OBCD2 port on cars on these engines, but I do not see where that might be.
 
Sorry for the delay in replying. To answer your questions first. The alarm system, four lights located on the bottom of your tachometer, Check Engine, Oil Pressure, Temperature and Rev. Limit, when you turn the key to on(not start) all 4 lights will light up for about 3 seconds and the buzzer will sound. This is a self check of the monitoring system. If you have an issue with one of the sensors then the check engine light will flash a corresponding code accompanied with a series of beeps.

There is a port OBCD2 sort of. Suzuki uses their own proprietary system called SDS (Suzuki Diagnostic System). To my understanding if you have analog gauges then it will be capped off, if you have digital gauges then the SDS plug will be used to send data to your gauges or a MFD if equipped. I have analog gauges and haven’t looked for the SDS plug on my engine. (2009 DF90A) Google “Suzuki SDS” to get an idea of the SDS system.

https://www.suzukioutboardforum.com/filedata/fetch?id=44592

The above link shows a picture of the SDS plug on the last page.

Back to your issue, you think it’s fuel related so after cranking and no start, have you pulled a spark plug to see if it’s wet with fuel? If the spark plug is dry then I would suggest you work backwards along the fuel system looking for fuel related issues. If the spark plug is wet then check for spark at the spark plug.
 
Selffixer.com has a pdf service manual for $12. It covers 2009-2010, only one year short of your 2011 model. Might be worth buying for the manual for troubleshooting. I can’t see Suzuki changing too much from 2010 to 2011 but one must be careful using specifications published in 2010 for a 2011 model. Best would be using a 2011 service manual for a 2011 model but for $12 there would be some value in having a service manual even if it’s one year out of date. I purchased my service manual from them and had no issues.
 
See if there is fuel in the VST tank.----Clean the VST tank.----Ckeck float valve in the VST tank.-----Check filter in the VST tank.
 
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Thank you for the responses!

I will be checking off the suggestions later today.

I can say the plugs were dry when we pulled them and we put in new ones in place of the old.

Thanks again!

Will post new findings.....
 
I would like to apologize for ghosting this thread the responses provided by William01 and racerone.

Some pretty serious distractions came up and I was out of bandwidth. On the upside, things are returning to normal.

The tips on where the problem was originating were correct. I got a shop manual and looked into what would be required to access the high pressure portions of the fuel system. Between my lack of experience with these engines and the number of steps required to get to the problem I decided to find a good local shop to help me out.

I spoke with some local boaters and they suggested Dekalb Marine(https://www.facebook.com/dekalbmarineinc/).

The shop has been around a very long time. I spoke with Andrew and brought the boat over. They took care of the stuck float in the high pressure chamber of the fuel system. They also adjusted idle settings and various other details that I did not know existed.

The engine I thought was running well is now running much better than it was. Starts with a touch of the key, settles into a perfect idle. Pulls strongly. Just better in every way. So thank you Andrew.

Ans thanks to William01 and racerone. Yall were right on.
 
Good to hear. Now that you’ve got it running nicely and you have a service manual you will be able to stay on top of maintenance. I would suggest you purchase a genuine Suzuki maintenance kit, probably around $100. It will have all the parts you need. I would suggest you think about doing the water pump kit to that new to you boat. It’s a fairly simple job and if your not comfortable DIY then it sounds like you have a good shop to take it to.
 
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