Water in gas cap 2006 Ninja 250

[blkr]

Hey guys so my bike was running perfectly yesterday then today it must have rained a lot overnight and my bike was soaked. Opening the gas cap(I have the screw on kind) there was water inside that seemed like it was getting in from where the tank vents pressure. My bike would not stay running without full choke and eventually died and would not restart. I have had this problem before and replaced the gas cap with a new one from eBay, yet it still seems like it doesn't keep all the water out of the tank. What do you think I should do?

[csmith12]

Welcome Noah!

I would bet your overflow drain/tube is clogged or.... the side fairing top bolt(s) have penetrated your tank and allowing water to drain in.

Another issue on older tanks is imperfections in the fill hole. A little ding from the pump nozzle or dirt and corrosion too can cause it to leak.

Let's hope it's just cleaning a drain. /fingerscrossed!

[blkr]

Your talking about the black tube running from the tank down right? and when i unscrewed the gas cap there was water right under the cap so that must be where its getting in right

[csmith12]

Originally Posted by blkr

Your talking about the black tube running from the tank down right? and when i unscrewed the gas cap there was water right under the cap so that must be where its getting in right

Yea, the hose on the back of the tank is what carries the water/gas to the ground from your overflow on the tank. It is unlikely that water is making it's way from the tube, UP to the cap area. The fact is... when you open your tank and see water around the fill hole neck, you cap is leaking AND it isn't draining, Inside the tank, there is a drain tube to keep water from mixing with the gas as the water drains through the tank and out that rubber hose to the ground. See the illustration below. Ignore the, "Plug intake with neoprene or epoxy" silliness, as you have found out... that hole in the fill area is there for a reason. It's a pretty crappy picture, but should give you an idea about things.

[jkv45]

That cap, if it's the one I think it is, uses a large o-ring to seal around the perimeter of the removable part. Might want to look at its condition.

I think those have a gap (when tightened-down) that lets the tank vent by leaving space between the filler opening and the vent hole in the cap's base. All of the sealing is done by the o-ring.

We have a similar cap on our "Ninja Beater" that sat outside in WI all summer without any water issues.

[blkr]

Originally Posted by csmith12

Yea, the hose on the back of the tank is what carries the water/gas to the ground from your overflow on the tank. It is unlikely that water is making it's way from the tube, UP to the cap area. The fact is... when you open your tank and see water around the fill hole neck, you cap is leaking AND it isn't draining, Inside the tank, there is a drain tube to keep water from mixing with the gas as the water drains through the tank and out that rubber hose to the ground. See the illustration below. Ignore the, "Plug intake with neoprene or epoxy" silliness, as you have found out... that hole in the fill area is there for a reason. It's a pretty crappy picture, but should give you an idea about things.

taking off the gas cap, the area that is supposed to drain had a good amount of water in it which was expected, but I could not find any hole that it would drain out of. I have included some pictures so you can see what is happening. In the one with the gas cap removed I soaked up all the water before taking the picture

http://imgur.com/a/j40Ec

[csmith12]

I see the issue, it's installed it improperly.

The drain hole in the top pic should line up with the completely clogged/plugged drain hole on the bottom (ie be on the side stand side.).

Think about it, if the bike is on it's side stand and the lid leaks, where is the water gunna go? Yep, straight into the tank. Now if you rotate the cap base, the little hole is gunna be on the side stand side and drain it before it makes it to the center opening into the tank. Your bathroom sink in your house most likely has a hole like this as well to prevent the sink from overflowing.

Easy fix, just rotate your base install.

EDIT: try to clean up some of that fill neck opening so the rubber seal on your cap will make a tighter and cleaner seal. This is probably the reason water is entering the tank in the first place.

[csmith12]

An inside view of the tank showing inlet drain tube. All water and gas overflow should evac through this tube. If it is clogged or plugged, it will not drain properly.

EDIT: It can rust and allow water into the tank too. This is why some riders plug theirs and just deal with gas cap leaks.

[csmith12]

Sorry, dupe post.

[Motofool]

Originally Posted by blkr

Hey guys so my bike was running perfectly yesterday then today it must have rained............ What do you think I should do?

Welcome !!!
No matter how well the cap fits its seat, rain will leak inside the tank during a heavy storm.
That hole and hose can only drain so much.

The only solution is to protect the cap from heavy rain by placing some plastic cover over it or by keeping the bike from getting showered.

If water leaks into the fuel, it will end up inside the bowls of your carburetors sooner or later (normally at the worst possible moment).
At that moment, the jets will not be able to suck the water up (water is heavier than fuel and accumulates at the bottom of the bowls).

As that already has happened, you will need to drain the tank first and each bowl next.
Use a hose routed into a glass container, so you can see when the water stops flowing out not needing to empty the whole tank.

[FrugalNinja250]

The cap seals really well to the tank when all the rubber bits are in good shape, well enough that no amount of rainfall will allow water into the tank. That's why the key hole cover has a rubber gasket, and the gasket sealing the cap to the tank has five springs to apply pressure. If the rain falls faster than the drain tube can handle it simply fills up the cap recess and runs out the side of it. I would start by examining all the rubber bits first to see if anything is stiff or cracked. The drain tube you can check by filling up the tank and seeing if any gasoline runs out of the drain tube nipple at the back of the tank. If no gas there, then no leak. You can also pour a bit of gasoline down into the drain tube to see if it runs out the back to make sure it's not plugged.

I've got over 80K miles on my '06 now including driving rainstorms, both riding in and parking in, and never got any water in my tank.

[blkr]

Originally Posted by csmith12

I see the issue, it's installed it improperly.

The drain hole in the top pic should line up with the completely clogged/plugged drain hole on the bottom (ie be on the side stand side.).

Think about it, if the bike is on it's side stand and the lid leaks, where is the water gunna go? Yep, straight into the tank. Now if you rotate the cap base, the little hole is gunna be on the side stand side and drain it before it makes it to the center opening into the tank. Your bathroom sink in your house most likely has a hole like this as well to prevent the sink from overflowing.

Easy fix, just rotate your base install.

EDIT: try to clean up some of that fill neck opening so the rubber seal on your cap will make a tighter and cleaner seal. This is probably the reason water is entering the tank in the first place.

I thought that the hole in the top picture was to vent the fumes from the tank, not to drain water. Thats why its installed in that gap on the second picture, where the gap in the rubber gasket goes so the tank can vent.

[FrugalNinja250]

Originally Posted by blkr

I thought that the hole in the top picture was to vent the fumes from the tank, not to drain water. Thats why its installed in that gap on the second picture, where the gap in the rubber gasket goes so the tank can vent.

The top picture isn't of a pregen Ninja tank. I have no idea what it is.

The pregen tank vent comes in two varieties, California emissions and 49-state emissions. You can tell which you have by the number of hose nipples on the back of the tank under the front edge of the seat. Three and it's California, one and it's 49-state. The extra two nipples on the CA version are for the evaporative emissions control system.

On both models the tank is vented through a series of check valves and a labyrinthine passage in the cap designed to restrict fluid flow in the case of the bike falling over. The 49-state model vents out through a nipple on the underside of the cap into the recess under the filler cap. Any liquid that makes it through the venting system runs to the drain tube opening and down to the bottom of the bike through a rubber hose. On the CA version that nipple connects with to another, separate tube inside the tank via a rubber-sealed contact point in the recess. That separate tube goes to the evaporative system and carries both vapor and liquid. There's a liquid separator in the charcoal canister that takes any liquid and pumps it back to the top of the tank via a third hose and tube inside the tank.

In no case does any vapor vent directly from any holes in the tank itself as shown in the top picture above.