Premix question, safe to mix mineral with synth?

[amp3d]

The previous owner was running normal 2 stroke oil premix'd for about 5 hours or so prior to selling me his ski. He was mixing it a bit rich he "claims" to break it in.

I'm just going to use the XPS synth since thats what I use in the other seadoo.

My question is, should I run the ski out of gas before filling the tank with premix'd XPS? Or is it ok to just top it up now with synth and have it mix with whats in there (about a half tank of normal shell 2stroke oil).

I don't wanna mix them if its going to change the oil properties in a negative way...

 

[racerxxx]

I'd drain and refill. Run the drain thru the lawn mower

 

[racerxxx]

I'll assume you're referencing your 96 XP.

 

[amp3d]

Yes thx xp sorry. Crap I was hoping didn't have to drain. Balls!

Is there a simple way to do it? Removing the tank was difficult for me before. I assume draining the normal hose that goes to carbs will take forever!

Has Anyone ever wet vacuumed a gas tank. Lol

 

[ace422]

Ive drained my tank a few times using a cheap $5 siphon hose with a hand pump i picked up at autozone. Using a vac would not be safe.

 

[amp3d]

Ive drained my tank a few times using a cheap $5 siphon hose with a hand pump i picked up at autozone. Using a vac would not be safe.

I'll do this. Thanks.

 

[mikidymac]

I assume you still have a way to keep oil in the rotary valve cavity?

 

[amp3d]

I assume you still have a way to keep oil in the rotary valve cavity?

I'm leaving oil hoses in place

 

[RodInEscondido]

Ok, so I am a little confused (so what's new?). Are you saying the original oil injection system is disabled and blocked off or using oil injection system with pre-mix (which is common for a short period following major engine work)?

I have successfully drained tanks by disconnecting the fuel line from the carb input, connecting a length of clear (vinyl will work for this) line, select reserve on fuel selector, start siphon into gas can under ski, go have a couple cold drinks (this is a bit slow). The clear line should not get bubbles (indicates air leaks).