Couple maintenance questions about my 1990 Suzuki DT15

simplystressed

Petty Officer 2nd Class
Joined
Mar 16, 2009
Messages
176
Hi all, I just picked up a 1990's Suzuki DT15 outboard and I had a few questions hoping you can help me with:

1. MotorOil. It calls for TCW2, but I understand TCW3 is the new standard. Is this ok to use and is there a preferred type you guys use?

2. Gear Oil. What type of SAE90 oil do you guys like best? Is synthetic ok to run in the older motors?

3. Flushing. I notice the "telltale" hole isn't flowing as much water as it should, can I hook a hose to the flush port to clean it out while the motor is off? I'd prefer to get things flowing rather than running the engine if its not cooling enough.

I'd truly appreciate your feedback with my questions.:cool:

Thanks.

SS
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Couple maintenance questions about my 1990 Suzuki DT15

TCW3 is the latest standard and as new standards appear they are better than the old and therefore supercede them. Any lower unit gear oil is ok -- synthetic or not. Flusing is fine but you can't tell how well the tell tale is actually flowing when running on muffs as water is being forced through the system under house pressure. Only with the engine in a test tank or in the lake can you get a good idea of tell tale flow. If you are in doubt, replace the impeller. It is cheap insurance.
 

simplystressed

Petty Officer 2nd Class
Joined
Mar 16, 2009
Messages
176
Re: Couple maintenance questions about my 1990 Suzuki DT15

Hi Silvertip,

I appreciate your reply. I'll get it out on the lake and check the flow. One question though:

If it is flowing fine through the exhaust port on the upper back of the lower unit, does that indicate the impeller is ok and it's just a clog on the telltale?

Also, what about synthetic injector oil like this stuff: http://www.amsoil.com/storefront/HPI.aspx - is it fine to use as well?

I think there's some old gas in the tank also. Should I get rid of the gas or is there an additive to put in to help it? I doubt the guy used stabil.

Thanks again.

SS
 
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