P500 Submerged P500

[Keebler]

Saturday the wife and I had the P500 out for a nice day ride. I had been on the trail many times over the years and the water crossing is long but not that deep. The wife said don't do it and I said it will be fine, not so much! The water was stirred up and I could not see the bottom. Running in about a foot of water and crawling along slowly the front dropped and before I could stop and backup the air intake went under and game over. Some ATV riders helped pull me out and then pulled me back to the truck. I checked the air cleaner and it was full of water. I checked the oil and it was at the same level so I thought I had lucked out there. I took the intake manifold boot off and water poured out. I took the spark plug out and cranked the engine until it no longer was spraying water, then squirted some oil in the cylinder and cranked it a couple more times then put the plug in and started the engine. It ran for about 3 minutes and spit a bunch of water out of the exhaust, then died. At that point I had done all the damage control I could and headed home. At home I drained the front and rear axles, the engine oil and the gas. All fluids were contaminated with water. After draining I refilled with oil and a gallon of gas and started the P500, then let it run for about 30 minutes to dry out the exhaust and circulate the oil. I plan on running the P500 around a parking lot tomorrow then changing all the fluids again. I am a bit worried about the cooling fans since it is vented, should I replace the fan or just take it off and make sure there is no water in it then oil it? My longer term plan is to order a new piston, rings, and valves since they were hit with cold water while hot. What else should I be concerned with?

 

[Admin]

 

[T Bone]

Saturday the wife and I had the P500 out for a nice day ride. I had been on the trail many times over the years and the water crossing is long but not that deep. The wife said don't do it and I said it will be fine, not so much! The water was stirred up and I could not see the bottom. Running in about a foot of water and crawling along slowly the front dropped and before I could stop and backup the air intake went under and game over. Some ATV riders helped pull me out and then pulled me back to the truck. I checked the air cleaner and it was full of water. I checked the oil and it was at the same level so I thought I had lucked out there. I took the intake manifold boot off and water poured out. I took the spark plug out and cranked the engine until it no longer was spraying water, then squirted some oil in the cylinder and cranked it a couple more times then put the plug in and started the engine. It ran for about 3 minutes and spit a bunch of water out of the exhaust, then died. At that point I had done all the damage control I could and headed home. At home I drained the front and rear axles, the engine oil and the gas. All fluids were contaminated with water. After draining I refilled with oil and a gallon of gas and started the P500, then let it run for about 30 minutes to dry out the exhaust and circulate the oil. I plan on running the P500 around a parking lot tomorrow then changing all the fluids again. I am a bit worried about the cooling fans since it is vented, should I replace the fan or just take it off and make sure there is no water in it then oil it? My longer term plan is to order a new piston, rings, and valves since they were hit with cold water while hot. What else should I be concerned with?

Man that’s a bummer! How deep was the water when you went under?

 

[HUCK]

Saturday the wife and I had the P500 out for a nice day ride. I had been on the trail many times over the years and the water crossing is long but not that deep. The wife said don't do it and I said it will be fine, not so much! The water was stirred up and I could not see the bottom. Running in about a foot of water and crawling along slowly the front dropped and before I could stop and backup the air intake went under and game over. Some ATV riders helped pull me out and then pulled me back to the truck. I checked the air cleaner and it was full of water. I checked the oil and it was at the same level so I thought I had lucked out there. I took the intake manifold boot off and water poured out. I took the spark plug out and cranked the engine until it no longer was spraying water, then squirted some oil in the cylinder and cranked it a couple more times then put the plug in and started the engine. It ran for about 3 minutes and spit a bunch of water out of the exhaust, then died. At that point I had done all the damage control I could and headed home. At home I drained the front and rear axles, the engine oil and the gas. All fluids were contaminated with water. After draining I refilled with oil and a gallon of gas and started the P500, then let it run for about 30 minutes to dry out the exhaust and circulate the oil. I plan on running the P500 around a parking lot tomorrow then changing all the fluids again. I am a bit worried about the cooling fans since it is vented, should I replace the fan or just take it off and make sure there is no water in it then oil it? My longer term plan is to order a new piston, rings, and valves since they were hit with cold water while hot. What else should I be concerned with?

No . Follow through with the ride and drain at least one more time and ride it . If you damaged the piston and or rings it will let you know . As for the fan NO ,just be sure it's coming on . All will be fine . MOST IMPORTANTLY , NEVER DO IT WHEN YOUR WIFE SAYS DON'T ! Been there done that . Wife ,Isn't driving 120 in this heat really hard on the engine ? Me , No these Northstars are bullet proof . Cadillac ....no we aren't engine croaked within a few miles .

 

[Keebler]

Water depth was just over the air intake, dash display never went under. The P500 did sit in the water for about 20 minutes while help was arriving. Wife was great with the whole thing. I did hear a big shriek when the very cold water flooded the cab, then again when my wife tripped over a rock and got totally soaked. I never heard "I told you so" or what I was thinking "what a dumb ass move". I am going to modify the P500 with the snorkel mod and move all vents to the top of the cage, then make every attempt to never need the mod. Life lesson learned again; I have a really great wife and I have no common since!

 

[pappyo]

Mother nature has her way of changing the terrain above & below water line.
After setting that long under water you may want to consider checking anything that has a BOOT. ( Axles & Steering Rack )
Acquire some boot clamps ( lg. end ) checking now will save $$$ --& -- :\◇☆¥#@!>_⊙¿[*--?? -- a Year from now.

 

[The Green Goat]

When I was a kid, I used to ride 2 stroke dirtbikes all the time. When I submerged one (happened often), I would throw a rope over a tree limb and attach it to the front tire. I'd 'winch' it up until it was vertical and all the water drained out. changed the plug, and kept going. Always seemed to work for me. You should try that.



And post pics.


On a more serious note, I think you will be fine. Change the fluids, run it hard and hot to dry it out, then change them again and move on with life. Unless it gave me any indication that there was a problem, I wouldn't mess with the cylinder and such. Maybe throw a compression gauge on it to put your mind at ease.

 

[Jerryg]

See if you can get a look at the top of the piston. If it's cracked, broken or chipped, do not run the engine again.

You may gouge the cylinder wall beyond repair.

 

[Keebler]

I put a borescope in the sparkplug hole and the top of the piston and cylinder walls look good. I ran the P500 for about a hour in our church parking lot and it ran good, but I now know what everyone means when they say it has a lot of mechanical noise. I never ran it at speed without helmets before, I now have another good reason for a helmet! Thanks for all the help, I will pull the boots and check for moister.

 

[Ohio4x4]

If it didn't hydro lock and bend the valves and or connecting rod just run it. If it starts smoking you may as well go completely through it. We've drown several atvs one of them a 2016 forman 500 drowned to a stall. several oil changes and flushes to get the water out and all has been well for 3 years. Only a couple out off 10+ events had any real consequences both were attempted to crank before clearing the cylinder and both had been drown multiple times prior. Both were completely rideable one smoked like hell and the other had a rattle for a few years until rebuilt. Just keep an eye on condensation and keep the cylinder wall lubed well if you have to leave it sit my brothers forman had milky coming out for a few rides even after heavy flushing the day it was drowned. Good luck with it we'd love to see some pics.

 

[alloutdoors]

I do not believe you can change the oil too many times now, because you really want all silt/sand, etc., out of the engine/crankcase because it will continue to make its way to the rings, transmission, etc. If you are handy, I would be breaking down the engine/crankcase now vs waiting till later...

 

[Keebler]

I changed the oil after a hours of easy riding and the oil looked great. The front and rear differential oil was a different story, it was still milky looking. Will run another hour or two and change the differential oil again. I don't have pictures of the poor P500 under water but I do have pictures of it partially disassembled. Now for the forum challenge, I have two left over bolts that I can not figure out where they go. They have a 8mm head and the treads are about 5/8" long. I am pretty sure they came from under the airbox but can not find where and my old feeble mind remember taking them out but not where, any thoughts from the mechanically inclined?

 

[trigger]

Those look like the ones that attach the rack to the brackets on the bed frame.

 

[Keebler]

Nope, the 8 rack mount bolts are either 10mm or 12mm heads and about 2 inches long, those I know of and have in place. These bolts where in the same container so I know it was somewhere under the rear plastic and had to come off for me to get to the throttle body. The two bolts were close to each other and held the same whatever in place, I think. I have looked at the exploded view for the air cleaner assembly but know dice. I have take then airbox off twice to look for where the bolts go, but with no luck. I hate extra parts.

 

[hallic]

Well... start taking it back apart until you find 2 empty nuts?