[Wtfo611]

Just recently purchased a 2019 Honda foreman 500. Bike came with snorkel, lift, tires. Besides that everything else is stock. When out on the first ride it shut off as soon as the plug and exhaust went under water. I tried the dielectric grease in the boot and still keeps dying. I read somewhere that back pressure on the stock exhaust is the culprit? Is this true? If so what exhaust and tuner would you suggest? Not trying to be loudest out on the trail or blow $1000 on something that wasn’t the problem. Anyone else having these issues!?!

 

[mrbb]

welcome to the site
I'm no help on the water side, as I don;t use atv's that way, so no first hand experience in doing so!

 

[retro]

None of the electrical system is waterproofed from the factory, never has been, never will be. That is the owners responsibility. You'll have to remove the fenders and dielectric grease every harness connector on the ATV to waterproof them.

 

[SamUK]

@retro is correct with the above information..

Dielectric grease ALL connections and try again. If you have no luck try holding revs on as you enter water, this would usually determine your 'here-say' theory on stock exhaust back pressure.
Personally, I'd say it's an electrical issue.

As for tuners and exhausts... Keep the stock exhaust, it will make absolutely NO difference on a Honda other than making a lot of noise! Tuners I'm not really familiar with however, knowing Honda motors, it won't make a great difference either.

How did the previous owner ride this ATV? Have you contacted him/her?

 

[SamUK]

Something I should mention...

How is the ATV in question snorkelled? By this I mean, what size PVC pipe, how many bends, any tight bends, what size pipe from the airbox, how tall is the riser??

All are major contributing factors that the stock fueling management won't cope with.

 

[Wtfo611]

The snorkel is 2” all the way to the air box. The rise is and I’m guessing around 14-18”. from the riser it goes down to a heavy duty corrugated flex pipe and then straight to the air box. I am the 3rd owner and the previous owner said he only owned the bike for less then 20hr with 85 total on it when I bought it. Upon purchase, this quad looked like it was babied, no mud or sand anywhere and I mean anywhere on the bike. I pretty much tore it down in his driveway to check, thinking I would find evidence where the motor or header would have baked it on there. Will most definitely dielectric grease all the electrical plugs and try again.

 

[SamUK]

The snorkel is 2” all the way to the air box. The rise is and I’m guessing around 14-18”. from the riser it goes down to a heavy duty corrugated flex pipe and then straight to the air box. I am the 3rd owner and the previous owner said he only owned the bike for less then 20hr with 85 total on it when I bought it. Upon purchase, this quad looked like it was babied, no mud or sand anywhere and I mean anywhere on the bike. I pretty much tore it down in his driveway to check, thinking I would find evidence where the motor or header would have baked it on there. Will most definitely dielectric grease all the electrical plugs and try again.

In all honesty it's been snorkelled for a reason, most likely to go deep and maybe secondly as a precaution, the first would be where my money is if I'm honest.

I would certainly dielectric grease every electronic connection and try again. Failing that I would fit a 6" (long) reducer from your 2" Flexi to the airbox, reduce the nominal bore to 1 1/2" and see how that works for you.

If I remember rightly @mac102004 had mentioned something a while back about snorkelling a 500.

 

[M_Quick]

3rd owner of a 2019!

Sent from my SM-G930T using Tapatalk

 

[Wtfo611]

The snorkel is 2” all the way to the air box. The rise is and I’m guessing around 14-18”. from the riser it goes down to a heavy duty corrugated flex pipe and then straight to the air box. I am the 3rd owner and the previous owner said he only owned the bike for less then 20hr with 85 total on it when I bought it. Upon purchase, this quad looked like it was babied, no mud or sand anywhere and I mean anywhere on the bike. I pretty much tore it down in his driveway to check, thinking I would find evidence where the motor or header would have baked it on there. Will most definitely dielectric grease all the electrical plugs and try again.

In all honesty it's been snorkelled for a reason, most likely to go deep and maybe secondly as a precaution, the first would be where my money is if I'm honest.

I would certainly dielectric grease every electronic connection and try again. Failing that I would fit a 6" (long) reducer from your 2" Flexi to the airbox, reduce the nominal bore to 1 1/2" and see how that works for you.

If I remember rightly @mac102004 had mentioned something a while back about snorkelling a 500.

This snorkel, lift, tire combo was done by a Honda dealership as an extra. Deg will be done this weekend! A reducer?! What benefits would a reducer bring besides restricting air flow? Bigger the better from my understanding. I’m really Hoping that once all the plugs are sealed up the problem is resolved.

 

[fishfiles]

WTFO' , I ride old school Hondas so something are different than your 2019 , but I find there is a difference between won't idle under water and engine kills under water , in my case with 300s and 450s , if the something in the electrical system it goes to spitting then dies ----- so I think your problem is in the air intake system , what Sam is telling you about a reducer is to create a orifice and change the pressure of the sucking of the air , the thing to do to test that easily is a shop rag and some tape , fold a rag over twice and tape it over the inlet of the snorkel then try it , then go 4 layers of rag , then 6 , then 8 anmd see if it makes the engine run better ------ would almost be positive you have fuel injection , never owned a fuelie yet , it may need a bigger snorkel , 2 1/2 inch maybe , you might be too restricted

 

[Wtfo611]

I’m thinking it’s electrical or in some weird way the back pressure/o2 on the exhaust. I’d like to think that if it were the snorkel it would cut off in or out of the water. I’m going to work and play on it tomorrow so I’ll post what I find and if anything helped.

 

[fishfiles]

You might be right , as I think I seen you posted some different symptoms that it is doing on another site ---- if that wasn't you on the other site , then they have the exact same problem

 

[Durite42]

I own a 420 rancher fuel injected i never dielectric greased any connection and run 11/2 pvc snorkle and mine will idle all day in water my cousin has 2 inch snorkle and his has died under water a few times for no reason at all cost him a oil change 2 of those times

 

[the big green honda]

Just recently purchased a 2019 Honda foreman 500. Bike came with snorkel, lift, tires. Besides that everything else is stock. When out on the first ride it shut off as soon as the plug and exhaust went under water. I tried the dielectric grease in the boot and still keeps dying. I read somewhere that back pressure on the stock exhaust is the culprit? Is this true? If so what exhaust and tuner would you suggest? Not trying to be loudest out on the trail or blow $1000 on something that wasn’t the problem. Anyone else having these issues!?!

i am no expert but u could buy the o2 sensor delete might that help and also u can also do a copper 90 mod

 

[Eric the red]

i am no expert but u could buy the o2 sensor delete might that help and also u can also do a copper 90 mod

Watch mud puppys youtube videos on those mods, they do nothing.
Either the motor cools off when it goes under water tightening up causing drag or the air intake sensor cools off causing the stall. After you ride around in the deep water for a bit and everything is cooled off they idle. Guys also claim that after a bunch of miles/hours they stop stalling in water.

1 1/2 inch snorkels are a hair smaller than stock, this should make it run a little richer and may help a bit. 2 inch snorkels are a little bigger than stock. My brothers 520 rubicon gained a little power when he added the 2 inch snorkel.

 

[ferrosteven]

welcome to the site
I'm no help on the water side, as I don;t use atv's that way, so no first hand experience in doing so!

Lol so why did you make a post ?

 

[Pradicon]

@Wtfo611,
Can you please update how did you solve the problem your posted here?

 

[Eric the red]

I doubt he's still on here.
I've snorkeled mine and experimented with snorkel size. I used all 2 inch abs except for a foot or so of 1 1/2 inch abs in the middle where you cant see it to get it to run it's best. All 2 inch abs for the snorkel is a touch lean on the 520's. My brothers has all 2 inch abs with a short little piece if 1 1/2 in the opening to choke it down to the right size, it runs better that way, they're lean and ping under heavy load with all 2 inch.
Mine still wont idle under water until I sit in it for a couple minutes. Everything is sealed up and dielectric greased.
You can watch the temp gauge drop to 1 bar when you go into motor deep water, that's the problem and it's not really fixable.
There's band aids tho, leave the throttle cables adjuster loose and crank up the idle when stuck in deep water.

Just a heads up if you stall a few times in muddy water your exhaust will start to plug up. I had to drill a hole in the spark arrester as mine was plugged with mud, I couldnt hit top speed anymore but drilling the spark arrester out fixed it.