Pre-Mix Setup?

[SigEp368]

Admittedly, I am new to the Seadoo world, but I am confused about Factory set-ups vs Pre-mix mods. I have a pair of 94 & 95 GTXs that I just got running this year. They both have oil tanks, and all the lines running to the engine. From what I can tell, the previous owner ran straight gas, and I know it was oiling from looking at the exhaust when I purchased them.....how well it was oiling I do not know.

After reading some posts and horror stories, I have become a bit paranoid about the reliability of the 20+ year old oil pumps. Since then I have been running pre-mix, just in case.

Is this okay, or should I either convert it or just run straight gas?

 

[crimson]

I have a 95 gtx and recently had the same problem and converted to premix because my oil pump stopped working right and fried a cylinder and piston. Converting to premix is not had to do at all. You can run straight gas but you have to make sure the oil pump runs correctly.

The way you are doing it right now won't really hurt. But it might to be easier to convert to one way and be done with it.

 

[SigEp368]

I have read the manual for checking oil pump operation, and have ensured the clear lines are full and the adjustment is right. Is there anything else I can do to check and see if it is oiling correctly. I know on outboard I have worked on they have you measure the flow over a defined time to see if it is getting proper oil flow, is there a spec for that, or is there an easy way to see if it is oiling (e.g. Hold oil lever open while idling and check for increased smoke or drop in rpms)?

Id hate to disable them if they are working, cause it sure world be alot easier to run without premixing.

If I do disable, what does that involve?

 

[crimson]

Not sure how to check the oil flow, except checking ur cylinders and seeing how dry and covered in oil they are.

If you convert to premix all you have to do is cut the oil line going from the tank to the pump (the one with the big filter on it). Cap the line on the ends that are now open. And then mix your gas at the right ratio and ur good to go

 

[SigEp368]

Thanks for the info. This method ensures oil is provided to the crankcase? I thought I had read somewhere, about someone not converting it right and it potentially damaging the engine.

Please don't misunderstand, I am not doubting your guidance, just trying to understand how it all works.

Thank you for the help!

 

[crimson]

Well the oil tank serves as a reservoir for the 3 oil lines, one goes to the oil pump and the other 2 go to the engine to keep it lubed. Once you cut that line going to the oil pump you will be able run total premix. And the other 2 lines won't be affected at all by this because you are mixing the oil in the gas. But you must make sure the oil tank still has a decent amount of oil in it so it can supply those other 2 lines. Once you've cut the line, you are on total premix and you are ready to mix the gas, all you have to do is make sure it's mixed at the right ratio.

 

[SigEp368]

Excellent. That was the part I wanted to confirm. Thanks again.

 

[howie099]

The oil pumps rarely fail. U can test with a drill in reverse and when you replace the small lines you will actually see the oil fill the lines when you hold the pump open to prime them. You can't get new pumps for 657's and 587's anymore so you are stuck with getting used ones. You just replace the little lines every few years with the oil filter, use the correct oil in them, replace the seals on the tank if leaking, and replace the main feed lines when they look/feel bad you will be fine.

If you eliminate the pump you need to keep the rotary valve lines to the oil tank or loop them. The bad part with looping if you have weak or leaky main seals you will run out of oil and lock up the engine. Pre-mix is 40:1 so you will suck oil up pretty fast if you ride a lot.

Most of the time you lock pistons from not getting enough fuel which it turns leads to the fuel system not being maintained. If you have no oil the ski will be gone in like 5 mins of riding tops.

Here is what I can tell you I have 1998 1800 Sportster w/dual 717's with the same pumps on them and they work fine. I have a 2001 GTi with 717 still works fine, have 2003 skidoo 500 still works fine. My 95 GTX I do have the oil pump off right now since I am on my 2nd engine, but I am going to put it back on since I tested it by doing the electric drill test. I been just lazy since it rides and runs great..

The best way to test the system is mix oil in the gas tank and mark the tank and drive it. Oil goes down the system is working. You will just smoke more but I never fouled a plug using oil injection and having oil mixed in the tank. Unless you are like in super long no wakes.

 

[SigEp368]

Thank you for the reply. I winterized the skis, but I will try the oil pump test using the drill when I replace the oil lines. It's probably in the book, but if not, where do I hook the drill too? Does it require taking the carbs and cover off the RV?

 

[howie099]

With the drill test you need to remove the carbs and rotary valve cover to remove the pump and test it. When you replace the small lines and have the oil pump at max and you can see the oil move up the lines you should be good. When you do that test make sure the oil doesn't drop back down. If it does the check valves might be clogged or bad. Me I would just get new check valves from OSD. They sell a whole kit with lines, seals, and valves for like $30. If you take off the oil pump you need some carb gaskets and that also.

 

[SigEp368]

Good deal. I will go ahead and replace everything. OSD should make me a preferred customer. I have made a dozen orders since I got these things.

 

[snikwad003]

If you stay premix you need to remove the gear driving the oil pump so it isnt spinning dry. I would keep the oil injection if it was my ski.

 

[mikidymac]

I realize this is old but hopefully you see it before summer.
These oil pumps never fail and by never I think I have only seen about two on the entire forum. These are not like the ones Yamaha and Kawasaki used.

You should service them and that will tell you everything. You will also use so much less oil than premix.

1. Make sure you only use API-TC oil.
2. Replace the inline filter.
3. Replace the two small lines from the pump to the intake.
4. Adjust the oil pump per the manual.
5. Bleed the pump per the bleed screw.
6. With the ski idling hold the lever wide open and you will see the oil pulsing up the small hoses. When it reaches the intake you are done and confirmed the pump works.

 

[SigEp368]

Mikidymac, Thanks for the info. I actually haven't done anything to the ski since last season, but I am trying to get it ready for the lake before the weekend. I will double check the oil pump before I full them full of premix.

Just out of curiosity, what kind of inline filter can I use? Is it a special order item, or can I find something compatible at an autoparts store?

 

[mikidymac]

The oil pump filter and fuel filter are specific to the Seadoo's. Minnetonka4me might be able to get you them overnight.

 

[SigEp368]

Thx, I will check.