1997 XP 787 No Start / gash in hull

[GGuillot]

1997 Sea-Doo XP, 5662 Fuel System | Sea-Doo Warehouse

Could one of my issues be the fuel check valve (#37) and pressure relief valve (#18) not functioning? I was looking through the Carburetor adjustment sticky and found this excerpt; "A common cause is a carburetor needle(s) & seat(s) leaking fuel into the cylinders causing a hard to start condition when motor is hot. How can gas get past a needle valve other than what I have talked about? One way is if the fuel tank pressure release check valve in the OUT vent line thru rub rail is not functioning. The fuel pressure in the tank overcomes the spring tension on the needle valve and gas is FORCED past it. The valve should open at approx. 3-5lbs. psi."

I replaced all the fuel lines except the breather lines because they dont have fuel running through them so I didnt think they would affect carb/fuel function. This breather line has a T where it goes out the side of the hull and the top of the hull kind of by the handle bars. If these arent functioning, they could be the cause of my no start when hot due to flooding! I believe the carbs are good so I would like to try this before doing a carb rebuild.
Thoughts, concerns?

It can't hurt, just spray carb or brake cleaner in them and blow out with compressed air.

But I still think you'll need to rebuild the carbs with OEM kits.

 

[Sportster-2001-951C-Stock]

1997 Sea-Doo XP, 5662 Fuel System | Sea-Doo Warehouse

Could one of my issues be the fuel check valve (#37) and pressure relief valve (#18) not functioning? I was looking through the Carburetor adjustment sticky and found this excerpt; "A common cause is a carburetor needle(s) & seat(s) leaking fuel into the cylinders causing a hard to start condition when motor is hot. How can gas get past a needle valve other than what I have talked about? One way is if the fuel tank pressure release check valve in the OUT vent line thru rub rail is not functioning. The fuel pressure in the tank overcomes the spring tension on the needle valve and gas is FORCED past it. The valve should open at approx. 3-5lbs. psi."

Loosening the fuel cap will release vapor pressure building in the fuel tank. Yes, if the fuel tank pressure overcomes the carb metering system, the cylinders and crankcase will have abnormal quantities of fuel in them.

If your fuel return from the carbs to tank is blocked, you're likely to experience excess quantities of fuel as well b/c fuel control is disturbed during engine operation.

 

[Sportster-2001-951C-Stock]

The round metering diaphragm of the carburetor should be nearly as soft as a rose petal. If stiff, it's junk. There also should be no visible holes in this diaphragm, hold it up to bright light for inspection.

The aftermarket diaphramgs are often made incorrectly and stiffer than the original mikuni diaphragms, aftermarket diaphragms might be holding the metering needle open even when the engine is not running. A pop-off test with the diaphragm installed will reveal if this problem exists.

Rough Pop-off testing can be accomplished while the carbs are still installed, well enough to discover if a metering needle isn't returning against the seat or leaks for some reason. Isolating the two carbs for a real pop test will be somewhat more difficult in this case.

 

[Sportster-2001-951C-Stock]

As I’ve said several times recently, you’re either a member of the Genuine Mikuni parts cult, or you will soon be initiated.

I like the choice of the word "cult", I dribbled some coffee on my shirt when I read that one, LOL I hope I'm not one but I do agree aftermarket parts can't just be tossed in like the mikuni parts can and some of the aftermarket parts simply won't work properly b/c of their departure from the original design.

 

[mikidymac]

It is easy to check. Remove the vent hose from the sending unit. Air should be able to be suckend in withlittle to no resistance and should hole pressure to 3-5 psi then release above that.

 

[GrupaNation]

It is easy to check. Remove the vent hose from the sending unit. Air should be able to be suckend in withlittle to no resistance and should hole pressure to 3-5 psi then release above that.

I have a compression gauge, but i dont have small pump/ vacuum tester. Could I blow/suck on the line using my mouth to see if its holding pressure/ check vacuum? (not afraid of a little gas haha)
If thats not acceptable procedure I guess i could pick this up on the cheap. Fuel Pump and Vacuum Tester

"If your fuel return from the carbs to tank is blocked, you're likely to experience excess quantities of fuel as well b/c fuel control is disturbed during engine operation." I replaced the return line with new fuel line and I took the baffle pick up out to inspect the for cracks, and check for blockage. The return shouldn't be the problem.

I'm just not excited to take the seat off again to work on the fuel tank lines. That thing is a pain in the a$$. My new fuel selector petcock should arrive today so I will replace that too.

 

[mikidymac]

You can use your mouth to see if the inlet valve is working. Just a bike pump will tell you if the relief valve is opening.

 

[JeremyD615]

You can pressurize that line and check your vent system. There is no harm in doing that. Keep in mind that 3-5 psi is still more pressure than a lot of people can produce with their lungs, so you’ll need compressed air...

 

[GrupaNation]

Got the lines off. Cleaned them out and reinstalling with new fuel line as you read this.

 

[GrupaNation]

My VTS doesnt work.
I pulled the VTS and it turns off direct current in both directions. Is there a thread or video that shows how to trouble shoot the rest of the system to find where the fault is.

 

[JeremyD615]

Unfortunately I’d the motor is turning in bot directions, your module is shot... You’ll need to either buy a used VTS housing from Westside Powersports, or buy the trimfix setup.

 

[GrupaNation]

I dont really care if the gauge works or if the trim stays stock. Has anybody wired their own toggle switch to reverse the current flow? Shouldn't be hard, would just have to put a 5AMP or 7.5 AMP fuse in line.

 

[JeremyD615]

I dont really care if the gauge works or if the trim stays stock. Has anybody wired their own toggle switch to reverse the current flow? Shouldn't be hard, would just have to put a 5AMP or 7.5 AMP fuse in line.

There are several that have used a relay setup to make the VTS work. The downside to doing it that way is there are no end of travel limit switches if you wire it that way. When you hit the travel limit, the linkage will bind up and not work until you open everything up and physically reset it.

 

[GrupaNation]

Is there a trick to getting these set screws in the handlebars? They came out easy but wont go back in.

 

[JeremyD615]

I don’t know that there’s any trick to it. To be honest I’ve never had trouble with mine...

 

[GrupaNation]

In the process if taking apart carbs. My rebuild kit will arrive tomorrow. These things look really good compared to most carbs I see here. Why would they look so good but not function?

 

[JeremyD615]

Those do look like they’ve been gone through recently, but the hard part to clean is the internal passages, and that’s most likely where you have corrosion or gunk... Make sure you get a lot of carb cleaner forced through the jets and into all those little ports..

 

[Sportster-2001-951C-Stock]

Hey, while I'm thinking of it, on that hull patch I want to share how I minimize surface imperfections when I'm working with resins, it might come in handy for the OP.

Cut a section from a plastic soda bottle and lay it on top of the wet resin while curing and tape it down flat, lay a book on top or something like that.

Wax paper may work as well but not as stiff, or a section from a laundry liquid soap bottle (HDPE type plastic doesn't adhere to epoxy)

 

[racerxxx]

On the vts, Google DEI 451 relay Seadoo. Guys have used re-setable fuses/breakers so you don't have to take anything apart to replace fuses.

As far as the carbs, everyone is spot on. Only thing I'm not down with, they're either replacement mikuni's or someone stripped the paint of them.If they're replacement, are they jetted correctly?

I commend you on your effort, I've restored some real Salt turds. Yours, that would have been a parts ski to me with that hole in the bottom.

 

[GrupaNation]

I used regular kitchen plastic wrap for my first layer of marine tex but I forgot to do it for the final layer. If I ever have to do a repair like this again, I'll do a better job smoothing the puddy while the plastic wrap is on. Seems like a great technique if done correctly!

 

[Sportster-2001-951C-Stock]

In the process if taking apart carbs. My rebuild kit will arrive tomorrow. These things look really good compared to most carbs I see here. Why would they look so good but not function?

From the outside they look great. No telling if the tiny low speed passages are plugged with corrosion or like speedracer pointed out might have the incorrect parts in them.

 

[GrupaNation]

Do I need this one way valve? If so where can I get a new one?

 

[GrupaNation]

Found my problem. What would cause this?

 

[Sportster-2001-951C-Stock]

Found my problem. What would cause this?

Looks like water? Not sure what you see going on with that diaphragm.

 

[racerxxx]

It's torn, possibly old, or original.