What oil would you suggest to use in jet skis?

[Dargo]

I bought a couple newer jet skis this year that are powered by 4 stroke engines. My older skis all have 2 stroke engines and obviously don't have any oil to change. The manual with the newer skis isn't really that good and just says use a good 10w50 oil. But, it lists several other weights that would be okay. Anyway, the weight of the oil isn't my only question. Since one of them is a very high performance 250 hp supercharged four cylinder, wouldn't a high quality synthetic oil be better for it? The smaller of the two 4 stroke skis still has a 180 hp 1500cc engine. Needless to say, these engines are generally run pretty hard and sometimes are held wide open for long stretches.

I've noticed that some of the Amsoil diesel oil I have left says it's heavy duty diesel and marine oil. I assume that "marine" part would be for a diesel marine engine? Or, since the engines are worked so hard, would a gas engine benefit by having the higher TBN and other additives?

 

[thatguy]

Im sure others will have comments... But Amsoil does carry a couple 4 stroke marine synthetic oils.. They have a 10w30 (WCT is the code) and a 10w40 (WCF)

Here are some weblinks to product specs

AMSOIL - SAE 10W-40 Formula 4-Stroke® Marine Synthetic Motor Oil (WCF)

AMSOIL - SAE 10W-30 Formula 4-Stroke® Marine Synthetic Motor Oil (WCT)

I am slowly converting my stuff to a full synthetic, but others will say it is not necessary..

Good luck..

 

[vsteel]

Since mobile stopped making their 2 stroke oil (which I loved and thought was great.) I think the next best is K2.

Maxima Racing Usa - Formula K2

Its full synthetic and I use it in all of the two strokes I have.

 

[BJN644]

I'd run Mobil 1 0w40 weight in it. A lot of turbo car owners run it.

 

[tomd999]

Hiya,

No matter what brand you choose, (I prefer Amsoil for everything I own) make sure you use a marine or boating certified oil. These days with the enviro-nazi's out on patrol, having to pay for clean up of an oil slick at a public lake because the oil wasn't marine oil would really be a bummer.

As far as TBN number, Amsoil originally marketed the "para-synthetic" Diesel/marine oil as a great for gas fueled marine or long term storage engines because the high TBN # would help control corrosion.

Tom

 

[Kyle_in_Tex]

Dargo, if you have the brand I think you have, I've heard the dealers are wanting top dollar for an oil change. Partly due to the difficulty getting the old oil out. Get yourself one of those little pumps you can pump it out from the easiest orifice. Whatever you do, don't try to put a remote oil filter on it. It will inhibit the flow enough to kill your engine. Another fact of revving a 4 stroke near redline for extended periods is that they can pump a bunch of the oil into the topend faster than it can flow back into the sump. So make sure you warm it up decently before you nail it and make sure you use a really good multi viscosity (sp?) oil. Unlike a motorcycle, you don't have an internal clutch (I don't think) to worry about additives killing it.

I haven't got to ride one yet but I'd sure like to. Super High Output sounds good to me. I'm guessing brand 'Y'.

 

[Skyco]

The manual with the newer skis isn't really that good and just says use a good 10w50 oil.

10W-50? Thats an unusual oil......sure limits your choices, pretty much just motorcycle oil (high dollar of course) is made in that grade

 

[Dargo]

Thanks for the replies. I haven't changed the oil yet, but I did go out and buy one of those hand pumps (no, not that kind!). My daughter and I took one out yesterday in our wetsuits. On a sunny 60 degree day it was actually quite comfortable. I unfortunately found out how much a bad impeller affects the ski. Holy crap, talk about changing the performance! Rather than having gut wrenching 0-30 times in the 1 second range, this thing would just cavitate something fierce. I'd have to back off and feather the throttle to get it up and going. Even running 40 mph I could hit the throttle and have it cavitate badly.

Oh well, I knew the impeller was bad when I bought it and got the seller to take another $300 off the price for me to get a new impeller. I was just hoping I could get by with the bad one for a while but that isn't going to work. I'm going to order that new impeller Monday.

I haven't even checked the dealer for oil. In the past I've found that most all motorcycle and jet ski oil is made by a common refinery and just private labeled for the MC or PWC brand. Oh, Kyle, the speedster one is a couple year old version of this one Jet Ski® Ultra® 260X

 

[Kyle_in_Tex]

Dargo, this is the one I have my eye on.

2009 Yamaha FX Cruiser SHO Home, information, info

I'm trying to figure out how the impeller got damaged. Sand? Rocks? I was thinking the newer models have a stainless impeller which last pretty good. Watch out for floating seaweed or duckweed as we call it.