have lots of questions, need help asap

[papt99]

I just purchased a 99 GTI about 2 months ago. IT had been rebuilt last summer completely. The guy who had it converted to a premix and bypassed the oil injection. well the first time out it ran perfectly. But the last time, it started bogging down after about 45 minutes of riding. seems to not run well when the fuel gauge reads less than 1/2. So I looked at the tank and noticed that I have about 80% of full in the tank and the guage reads about 40%. Then I pull the plugs and they are both black on the ends with grime on them. Someone suggested yamaha ring cleaner to me.
So I think I have at least 3 problems: fuel gauge, bogging down (really feels like just not enough gas), and black plugs. I am a newbie and complete idiot when it comes to engine mechanics. I don't have a PWC service shop within 45 miles of home. Please help.

 

[Dr Honda]

1) Is the oil tank still in the hull, and hooked up to the Rotary Valve?

2) check the compression.

3) what oil are you using, and what ratio?


4) don't worry about the gauge right now.

5) do you have gray (or tan) "Tempo" fuel lines?

 

[papt99]

I have new fuel lines, the black ones. I am supposed to be using amsoil saber synthetic at 100-1. But I ran out and in a pinch bought something else. After talking to the person who sold me the ski, I think I was sold a two cycle oil that was designed for injection, not for mixing. SO......I will completely empty the tank and start over with the amsoil this time and hope this fixes the problem.
and yes the oil tank is still in the hull but it was professionally bypassed last summer so I am not too concerned that it is an issue.

Thanks for your help. I will update soon, hopefully with good news.

 

[purple_people_eater]

you need to run at least 50:1. i can't remember what the injector pump runs at WOT but i run 40:1 on my pre mix ski. it will foul your plugs quicker if you idle a lot, but is $5 for plugs and 10 mins to change them out vs having to rebuild the motor.

 

[seadooya]

theres oil out in the market, that the motor can run at that type of mixture..(golden spectro), but i dont recommend it.

Being a 720cc motor, you can run the mineral seadoo/quiksilver pwc oil, no need for synthetic. I'd start with draining the tank, premixing to 40/1, DOUBLE check to make sure the oil line from the oil bottle IS going under the carb, and another line coming from the other side of the motor, back to the res/oil tank, no this,....a "pro" mechanic did it last year..blah,blah,blah.

Mix your gas, install new sparkplugs, then try again. If a comp gauge is handy, throw it on and see what readings you get.

 

[Dr Honda]

1) The recommended "Pre-Mix" is 40:1 for a seadoo.

2) As Seadooya said... "Pro... Bla, bla, bla." We see it every year, and people wind up with melted engines. Most seadoo engines have a rotary valve, and that valve, and it's gears are lubed with oil from the oil tank. So... if you go Pre-Mix... you still need to have the tank hooked up, and at least half full of oil. When you go pre-mix, you disconnect the oil injection, and block it off... but you still need oil to the gears.

SO.... does the tank have oil, and is it hooked up to the center gears??

3) Did you check the compression yet? The number one, biggest No-No in the 2 stroke world is mixing oils. Bad things can happen. Unlike automotive oils... 2-stroke oils have a wide variety of base oils, and additives packages. They can react, and turn into Jello. When that happens... your engine won't last.



4) As said above... there is no need to run Interceptor in a 720 engine. Save the money, and run a good API-TC mineral oil, or synthetic mix. (Like XPS syth blend) NEVER RUN A TC-w3 oil in a SeaDoo engine.

 

[papt99]

well I finally figured out the problem. changed to new gas, got the right oil, changed the plugs and still was having the same problem. went to check the fuel filter and it wasn't dirty, but it WAS loose. tightened it up and completely fixed the problem. running up to 50 mph without so much as a hiccup. I was ecstatic. that was getting really frustrating. thanks for all the help you guys.

 

[Minnetonka4me]

The orings in those can crack and leak air too...good to hear you got it going!