2015 Suzuki DF20A will not try to start with compression, spark, and fuel present

[PNW Keith]

Hi! I am hoping for some guidance. I have a 2015 Suzuki DF20A (fuel injected) that will not start. The motor was subjected to a partial submerging and has been well cleaned up, including the installation of a new wire harness. The electric starter is currently off the motor (waiting for a replacement), however it will not even try to start with the pull start. The motor has compression in spec, spark at both plugs, and I have pulled both injectors and can see them firing when attempting to pull-start. The motor does to even try to fire - even on starting fluid - so I suspect timing. I have checked the timing marks and keys on both the flywheel and cam pulley - everything is as it should be. All sensors are plugged in properly. Thanks in advance for any advise.

[jHydroman]

What were your compression readings?

Jim

[PNW Keith]

60 psi with the start de-compression feature active.

-Keith

[jHydroman]

Not familiar with the decompression feature, but I know 60 PSI is to low for combustion engines, Is the decompression feature only activated when starting with pull starter. I suspect decompression feature isn't working correctly possible not getting to RPM for compression to build when using the pull starter.

Jim

[Moonlighter]

You could mess around for a long time with this, but the best way of diagnosing the issue will be for a Suzuki mechanic to connect up to the Suzuki diagnostic system to their laptop, they will quickly be able to check it out and test things to find out the problem.

You can buy after market SDS systems, but there is some knowledge and skill that goes with its effective use. I am not sure how good the manuals are that come with the after market versions....

[PNW Keith]

The decompression system uses a pawl on the camshaft that, at very low RPM, keeps the valves open for longer - thus making it easier to pull start. Once the engine gets up to any sort of meaningful RPM, certrifugal force spins the pawl out of the way and the valves stay open for the proper amount of time.

[Geoffreyspears]

I'm in the exact same boat (figuratively). Same year, brand and size motor only mine is the manual start tiller version...same mystery malady with the same symptoms. Mine has been running hundreds of hours since I bought it new in Feb 2016 and it's always been a two pull starter with plenty of power for my 12.5' Zodiac, but yesterday after I returned to shore from a couple of hours of boating on the lake, I turned it off and when I tired to restart it 15 minutes later it behaved like I had forgotten to insert the safety lanyard. The pull always feels the same since it uses the decompression system, but it never even sputtered or tried to start. I used a continuity meter on the kill switch and it had continuity when the lanyard key was removed and didn't have continuity when the key was inserted (just like it's supposed to) so, that eliminated a faulty kill switch as the culprit. Then I did all the stuff you did - pulled both plugs, grounded them and watched the pretty sparks with the lights out, then I pulled the injectors and watched the gaseous mist with each pull.

So, spark in both plugs, fuel in the cylinders and presumed compression since it was running really strong right up until I turned it off and it never started again. I tried to take it to the Suzuki service center, but it's Memorial Day weekend and they weren't accepting any new work - just trying to get boats back to customers for the weekend. So, I'm boatless and perplexed. All I know is the problem lies somewhere other than where I've looked.

Your post is from more than 3 months ago, so surely you were able to diagnose the issue and solve the mystery by now, right?

[Geoffreyspears]

I sorted out my DF20AS2's starting problem. Spark plugs. They looked fine and with the lights out, both had visible sparks, but when the multimeter couldn't read continuity, I decided to clean them with brake cleaner and 220 grit. Big improvement in spark intensity afterwards and an immediate return to one-pull start ups. Obviously, not all sparks are hot enough and the term "good spark" is pretty subjective, but these little plugs are pretty sensitive to even thin carbon buildup. I'm well within the plug replacement interval, but have been doing a lot of start-stop boating. Anyway, a strip of 220 grit SP just found a home in my boat's quick tool bag.

[Geoffreyspears]

It's good to be on the water for memorial day!