Is oil tank still needed when converting to pre-mix?

[DKFox]

I’ve got a 1998 SeaDoo SPX with the 787 engine. Previous owner had done race mods to it and also did the conversion to pre-mix. I noticed he simply ran a single hose from 1 side of the rotary vale to the other. He did not keep an oil tank at all. Is this correct??? Seems like I read that before somewhere too.



However, I also have a couple of other skis with the 720 engine. I was thinking of taking them to pre-mix as well. I was reading up on the conversion procedure and noticed on the SBT website it said to still KEEP the oil tank because the rotary shaft still needs an oil bath. The block off plate simply lets you get rid of the oil injection pump and the small lines going to the rotary valve cover.



So what is the correct answer? Oil tank or no oil tank when converting to pre-mix?

[Deanrw3]

No oil tank is ok to do. However you have to have oil in the lines that would run to the oil tank (a lot of people fill the lines and loop them as you say he did). Just make sure the loop line is full of oil and you should be fine. They have to be full to ensure the rotary gear is always in a bath of oil.

On the other hand, it is almost easier to just have the oil lines go back to the tank as they are and then just block off the line to the pump.

Either way is fine as long as the bath area always has oil in it.

[steach]

No oil tank is ok to do. However you have to have oil in the lines that would run to the oil tank (a lot of people fill the lines and loop them as you say he did). Just make sure the loop line is full of oil and you should be fine. They have to be full to ensure the rotary gear is always in a bath of oil.

On the other hand, it is almost easier to just have the oil lines go back to the tank as they are and then just block off the line to the pump.

Either way is fine as long as the bath area always has oil in it.

Yup...Dean beat me too it. Unless you need the space leave it alone.

[wdstang]

I was also told to change the oil in the lines about every 6 months.

[Ninetok]

2nd on changing oil had a guy who's rotary shaft gear toasted and the oil was burnt. He didn't have a tank only lines looped. Could have saved it if had changed the oil in crank case. All he had to do was un loop line drain them and pour fresh oil in.