Bypassing oil

[OGs]

I bought a 98 gs and decided to bypass the oil and go pre mix. I have been reading mixed things about bypassing it. Am i safe to leave it like that or should i put the pump back on. Does it affect the rotary valve if i do premix?

 

[mikidymac]

There is no good reason to go premix on these. The seadoo system is super reliable and you will use a lot less oil.

Either way you have to leave the tank with oil to keep the rotary gear lubed all the time. Just replace the inline oil filter, change the little 3/32" tygon lines from the pump to the intake manifold and use only API-TC rated oil.

 

[Sportster-2001-951C-Stock]

I agree, if you set up the injection system and maintain it, it's bulletproof and you'll be glad you did.

My feeling is you have to keep the rotary valve drive gears submerged in oil anyway, so why not use the injection as intended?

 

[OGs]

Tbh I’m new to this so I’m trying to learn as much as i can. I had a few people tell me if the pump goes bad I’ll blow my engine. So i jumped the gun i guess. Any way it’s going back in tomorrow. I was replacing lines anyway. Now my question is , you say it’s reliable, but how reliable?

 

[AKnarrowback]

I have only seen one oil pump fail in all my 30 years of working with Rotax motors, Sleds and Doo's combined, and that was a brand new unit. Don't bypass the pump, the odds are higher you will run straight gas one day and kill it.

 

[mikidymac]

Agreed, in 25 years working on these I haven't seen a single one fail. Everyone that blames the pumps it ends up being a lean carb that killed the engine, not the oil pump.

 

[OGs]

Ok. Good to know. I will be putting pump on tomorrow. On the bright side, i haven’t ridden it since I’ve done it. Thanks for the help

 

[mikidymac]

You will be fine keeping the first tank premix also just in case there is still some air in the lines.

Also you need to verify you are using API-TC oil.

 

[OGs]

I actually haven’t ridden it since i got it about two weeks ago. And i took all the gas out since ima put freshman and oil in it. But thanks for the tips. Also does anyone have a link to how to test the pump ? I heard with a drill?

 

[Sportster-2001-951C-Stock]

The Seadoo oil injection is known to be very reliable, failures are rare. For Yamaha 2-stroke skis you might want to change to pre-mix.

In any case if you suspect a problem, you still have the option of adding oil to the fuel as a temporary solution until it's confirmed the injection is working.

 

[AKnarrowback]

98 shop manual.

 

[Sportster-2001-951C-Stock]

The one gotcha you might run into is the pump oil nipple fittings can come loose from the housing. So be aware when attaching or removing the tubing to make sure the epoxy they use to cement the fittings in place hasn't been broken loose. Rough handling can do that.