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2016 Sportsman 450 HO EFI
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Discussion Starter #1
Good morning all.

I was recently "gifted" a 2016 Spoprtsman 450 HO EFI from a friend that drove it into his dam. It sat submerged for 24 hrs or so.
This is my first ATV but I have some mechanical knowledge and I'm an expert "disassembler" so I'm trying to fix it up for myself. The rear wheel bearings and at least one driveshaft are shot but they are easy to fix.
He said he spent $700 at the dealer after recovery to get it back up and running. Got it home and drove it around for 1 1/2 hours and seemed to be ok but the next day, it wouldn't start. I'm really not sure if this meant that it wouldn't crank or just wouldn't fire or just had a flat battery. He said the dealer told him it might be the 'starter motor'. I hate dealers......the thing cranks over no worries but this friend of mine wouldn't know spare tyre from a steering wheel. All the dealer wanted to do was sell him a new unit.
Anyway, I got it to my place. It was flat so I put some jumper leads from a battery I have and it fired straight away for a few seconds and seemed to stop when I applied a bit of throttle. It stalled like a carby engine would if it was cold and needed choke. Since then I cannot get it to even look like starting. It turns over like a champ but will not fire.
So far I have done the following.

1. Fully charged the battery. Battery is fine.
2. Checked the fuse box. It's perfectly dry.
3. Checked the ECU connection. It was a tiny bit damp with a tiny bit of green corrosion, I mean tiny, which I cleaned up and dried out. It really looks ok to me. As a side issue....how absolutely disgusting is it that the dealer gets a bike up and running after being submerged for 24 hrs and doesn't even disconnect/check the ECU plug. It was still damp!
4. Pulled apart the airbox. It has a pod filter which looks fine but I had this all apart whilst attempting to start anyway.
5. Fuel pump works fine. Disconnected from the injector and pumps fuel. Pulled the injector off and cranked the engine and fuel squirts like a champ.
6. Pulled the spark plug and there is HEAPS of spark.

So separately I have air, fuel and spark so why won't it start?

One concerning thing is that the display/dashboard/speedo doesn't work at all but it didn't when I got it and initially started.

Any thoughts/help would be appreciated.
 

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Grounds can be a big problem. Rust build up. Even if this is not the big problem ground will always be a lingering problem. Take the connections apart many times to clean the brass. Then use past to keep dry and clean.
 

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Crc makes a product called wire dryer. I would go to through every connector and spray them. Also the gas, dump it and put in fresh.
 

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2016 Sportsman 450 HO EFI
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Discussion Starter #5
Crc makes a product called wire dryer. I would go to through every connector and spray them. Also the gas, dump it and put in fresh.
I will check that out but the submerging happened weeks and weeks ago and the thing ran 90 minutes after coming back from the shop.

Agree with the fuel. Will do. I just hadn't because it was running.
 

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One of the sensors that monitor air flow, unsure on your bike, not excepting fuel to accelerate? The computer itself might be effected by the submersion.
 

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2016 Sportsman 450 HO EFI
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Discussion Starter #7
One of the sensors that monitor air flow, unsure on your bike, not excepting fuel to accelerate? The computer itself might be effected by the submersion.
Would the air flow sensor stop it starting at all, though?
the ECU is my biggest worry but I just don't understand how I have fuel and spark whilst cranking but it won't start.
 

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2016 Sportsman 450 HO EFI
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Discussion Starter #8
I just wanted to give an update as I sit here and slap myself in the face and share my experience.

IT WAS A FOULED SPARK PLUG!!!

Having not had much experience with single cylinder engines I failed to appreciate just how important the spark plug is. Sounds stupid, I know, but with a fouled/bad plug in a a car the thing will still start as it can rely on the other cylinders to fire. It may run a bit like shit but it will run.

With a new plug the thing started first click. Me happy. Now I'm just waiting on all the parts to arrive to do a full suspension rebuild and new rear axles.
Cleaning the thing is a bitch as it spent 24 hrs submerged. Everything is just stained brown.

Thanks to those who replied.
 

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Ouch, a day under water? That sucks, mine needed everything changed, all fluids, vent lines blown out, all snorkels full of mud and crap, after 5 minutes under. Good luck man. Is it running?
 
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