1990 SP 587 Oil Injection Disabling

[Raymond 88]

I recently purchased 1990 SP 587. I have been told that when it was rebuilt last winter the oil injection was disabled so just to mix the 2 stroke outboard oil and gas together. I know this is a pretty common practice and understand the reasons. It looks to me like to disable it the previous owner just disconnected and plugged the hose from the oil reservoir to the injector pump.
My question is this, Is the oil from the tank still going into the rotary valve and reservoir to lubricate it as there are separate fittings for the rotary valve and the return to the tank. How does this oil circulate if not by the injection pump? Should this oil be changed once in a while then? Should i move the oil filter from the oil injection to the rotary valve line?
One last question, any recommendation for a the best outboard mineral based oil to use for the pre-mix and rotary valve if it needs oil?
Thanks

 

[LouDoo]

I don't usually recommend disabling the oil injection system, but since it's already been partially done, and since this is an older ski, it's probably not a bad idea. But you need to finish the job.

I would recommend getting an oil block off kit, SBT sells them. Remove the oil pump, you will need to remove the carbs. and the intake manifold to do this, use the block off plate and plug the two nipples on the intake manifold. You will also need to keep the oil bath connected, you can do this by leaving the oil tank in the ski and the oil bath connected, or you can use a piece of hose connected to the inlet and the drain of the RV cavity.

Do NOT use TC-W3 outboard motor 2-stroke oil in your ski, in the 90SP you should be using API-TC mineral based oil. Your 99GSX RFI you should be using full synthetic API-TC injection oil.

Lou

 

[RodInEscondido]

What Lou said, but to amplify ...

Best to keep the oil tank in place, else you will need to keep a close eye on the oil line loop to insure you have lube to the RV gears (it tends to leak past the interior seals especially on the older engines). There is no circulation in the RV lube loop; I thought there was at first, but the experts convinced me otherwise. Seems to me from being on this site for a while that the majority opinion is to keep the oil injection system. No real need for the oil filter if injection system is removed.

Read and heed regarding proper oil, these engines are a special breed and although you can get away for a while with outboard oil, it will catch up with you usually at the most inopportune time (think way offshore with nobody else around ... and no magic paddle).

 

[SaltyDog251]

So what exact oil do you guys recommend?

I have a 90 GT that I'm putting a rebuilt engine in and I'll also be removing the oil pump and premixing.
.

 

[RodInEscondido]

PWC oil, same as you are using for fuel pre-mix; mineral is ok, semi or full synth will work fine, just more expensive. Not outboard oil, lotsa threads here on oil.

 

[howie099]

You need API-TC 2-stroke oil. If you have power vales/rave valves you need synthetic. For all other motors you can use any kind of API-TC you want. I personally use Mystik semi-synthetic oil. Cost is $18 a gallon for $4.50 a quart at Farm & Fleet. Amsoil has a nice product 2 that comes out to about $23 a gallon if you member there but you have to always order it and if you run out you have to wait for it to come in.