650/X-2 650sx vent lines...are they necessary?

[Jpass]

I am reassembling my '88 650sx. Is it really necessary to run the vent lines up the handpole and into those weird plastic boxes under the chin pad or is there a different way to do it or can I leave them out all together?
Here are some pics of what she looks like now.

 

[WFO Speedracer]

I usually just run a short piece of line directly off the tank with the check valve stuck in it, all the stock system does is create a way for water to enter the tank

 

[Jpass]

can u post a pic?

 

[Crab]

what wfo said

 

[WFO Speedracer]

Why is a pic needed, cut a piece of hose about an inch long, plug it on the pickup vent tube, put the one way on the hose and run with it.

 

[Vumad]

One way valve allow air to leak, so naturally fuel will leak as well. Flip the tank upside down and you might have a drop of fuel every 3 seconds. Leave your ski upside down for a hour and you might have a problem. Leave it floating upside-down in the water for 30 seconds, a few drops of fuel diluted in the water in the hull to be pumped/siphoned out when you right it up is not a problem.

The fuel tank vents air, and with that air is gas fumes. The risk of explosion is present if left that way for an extended period of time.

So no, you do not need a vent hose running up the bars. However, the risk of fire or explosion is increased with this method. How much? Probably a negligable amount. I personally have a 1" hose and a Vent. Kind of like those you can buy for an ATV but all plastic (a bit smaller than stock).

Leave the hood cracked when you store it. To be extra safe leave the hood off a few minutes before attempting to start after a long storage in the hot weather. I personally do neither. Don't flip the ski/tank over and leave it that way with fuel in the tank.

Safety first! :haha:

 

[Jpass]

Thanks for the tips. I am not hooking up the fuel selector or anything on this ski. Just pulling straight off the reserve line from the tank. My blaster was set up this way when I got and I like it.

So far I have the reserve going thru a filter and into the fuel pump. From the pump I have it feeding the carb. I then have the carb return line going to back to the tank. There is another line coming out of the tank and into a separator located on the front of the opening of the engine bay. The other end of the separator was always capped off. The one way valve goes off the remaining line out of the tank yes?

I always store it with the hood off when in the garage and when starting it for the first time.

 

[Jpass]

Why is a pic needed, cut a piece of hose about an inch long, plug it on the pickup vent tube, put the one way on the hose and run with it.

My bad. I wasnt thinking when I asked for the pic. Goes to show you that drinking and posting on forums is not always such a good idea.

 

[Vumad]

Thanks for the tips. I am not hooking up the fuel selector or anything on this ski. Just pulling straight off the reserve line from the tank. My blaster was set up this way when I got and I like it.

So far I have the reserve going thru a filter and into the fuel pump. From the pump I have it feeding the carb. I then have the carb return line going to back to the tank. There is another line coming out of the tank and into a separator located on the front of the opening of the engine bay. The other end of the separator was always capped off. The one way valve goes off the remaining line out of the tank yes?

I always store it with the hood off when in the garage and when starting it for the first time.

My tank has 4 hook ups. The reserve goes to the carb. The main fuel pickup is capped/plugged. One of the others is the return from the carb, and the last has a 2" hose to a one way valve (3 inches total, no addl' hoses, water seperator, nada). I don't have any filters or anything fancy.

The best way to do things? Probably not, but This works just fine for me.

 

[WFO Speedracer]

We had this discussion the other day, the one way valve is actually a one way valve up to a certain pressure, that pressure is usually about 5 psi, under normal operation the fuel tank pressure should be between 1 and 3 psi. Not much of an explosion hazard there really.

 

[Vumad]

We had this discussion the other day, the one way valve is actually a one way valve up to a certain pressure, that pressure is usually about 5 psi, under normal operation the fuel tank pressure should be between 1 and 3 psi. Not much of an explosion hazard there really.

The explosion hazards are the accumulated fumes in the hull. The stock lines vent from the bars to prevent venting into the hull and thus accumulated fumes. A backfire could in theory cause an ignition from the carb to the fumes in the hull, resulting in an explosion. The spark arrestor is not just to keep bits out of the motor but to break ignition sources returning from the carb. A moving ski is unlikely to develop such a problem, but a small possibility remains. A ski sitting on the beach in the sun for an extended period of time on a hot day is at an increased risk of explosion.

The risk of explosion is present. The statistic probability of such an occurrence being extremely low does not in itself does not negate the possibility.

 

[Vumad]

http://www.pwcforum.com/general-pwc-jetski-discussion/51-my-jet-ski-exploded.html

http://video.tbo.com/v/21867662/jet-ski-explosion.htm

http://www.youtube.com/watch?v=Exi3XXM13Z0

http://www.abcactionnews.com/dpp/ne...media-journalist-john-thomas-jumps-in-to-help

http://www.pwctoday.com/f27/two-injured-when-jet-ski-explodes-orange-county-lake-73121.html

I myself don't do anything fancy to prevent an explosion. I do however recognize the fact that the possibility of such an occurrence is present. Make w/e decision you like, but make an informed decision. Ignore anyone who tells you the possibility does not exist or only applies to other vessels. They are misinforming you. Boats run blowers before they start for a reason. Jet skis don't have them, thus the risks are higher.

 

[WFO Speedracer]

You should be removing the hood and inspecting everything before you ride. if it sits more than a few hours I always pop the hood and have a looksee, that takes care of any accumulated vapors.I haven't blown one up yet and I work on them every day. :wave:

 

[Jpass]

You should be removing the hood and inspecting everything before you ride. if it sits more than a few hours I always pop the hood and have a looksee, that takes care of any accumulated vapors.I haven't blown one up yet and I work on them every day. :wave:

I usually store the ski in my garage with the hood laying across the tray, so it is open. My Blaster is also stored with the hood up. I start them this way before I head out for two reasons. 1 to be safe and 2 to be sure they are running OK.

I wasnt sure if I should hook the one way valve up to the now open ON line from the tank or off the separator? Not sure if one is better than the other? The separator has always been capped on the outlet side. That's the way it was when I got it.

 

[subhard]

Can you post what valve you use?

 

[SIMPSON]

One way valve allow air to leak, so naturally fuel will leak as well. Flip the tank upside down and you might have a drop of fuel every 3 seconds. Leave your ski upside down for a hour and you might have a problem. Leave it floating upside-down in the water for 30 seconds, a few drops of fuel diluted in the water in the hull to be pumped/siphoned out when you right it up is not a problem.

The fuel tank vents air, and with that air is gas fumes. The risk of explosion is present if left that way for an extended period of time.

So no, you do not need a vent hose running up the bars. However, the risk of fire or explosion is increased with this method. How much? Probably a negligable amount. I personally have a 1" hose and a Vent. Kind of like those you can buy for an ATV but all plastic (a bit smaller than stock).

Leave the hood cracked when you store it. To be extra safe leave the hood off a few minutes before attempting to start after a long storage in the hot weather. I personally do neither. Don't flip the ski/tank over and leave it that way with fuel in the tank.

Safety first! :haha:

i have a check valve with just a little hose attatched to it too. the check valve lets air get in the tank to let it breath but shouldn't be letting air out or anything else out unless it's broken.