Tohatsu 9.8 4 stroke lower unit gear oil check

[rhunter73]

I have a new out of the box Tohatsu 9.8. I added the engine oil until it was *just* about full, but not quite.
I put it in a test tank *cough* recycle bin *cough* for an break in, smooth start, no worries.

I am taking the outboard out tomorrow for the fist trip.

I wanted to check the lower unit oil, which I understand is prefilled, but I just don't quite understand the instructions.

"To check your oil level, remove the top oil plug, insert a small piece of wire straight into the top hole approximately 1 inch and withdraw the wire. If oil is on the wire the oil level is correct, if not the unit must be refilled to the correct level."

I can't imagine this test to ever show any oil unless the lower unit was overfilled and spilled oil out when you took off the top oil fill plug/bung?

What am I misunderstanding?

Thanks,

Roger

 

[Sea Rider]

Re: Tohatsu 9.8 4 stroke lower unit gear oil check

Factory could be using less oil amount as not overfill upper plug when filling, oil must be changed once break in period is completed usually after 10-20 worked hours, so running with bit less oil is not an issue unless the whole unit is completely empty...

Happy Boating

 

[Bronlonius]

Re: Tohatsu 9.8 4 stroke lower unit gear oil check

I have a new out of the box Tohatsu 9.8. I added the engine oil until it was *just* about full, but not quite.
I put it in a test tank *cough* recycle bin *cough* for an break in, smooth start, no worries.

I see you've invested in the same hi-tech tank that I use. The little recycle symbol molded into it actually makes it superior to a regular garbage can, it allows the water to swirl in a manner which extends the life of your water pump impeller.

I can't imagine this test to ever show any oil unless the lower unit was overfilled and spilled oil out when you took off the top oil fill plug/bung?

What am I misunderstanding?

That's actually exactly the way they are filled. You fill from the bottom plug, and keep squeezing oil in until it oozes out the top. The factory probably fills a pre measured amount, so it might not be that high, but any lower unit change after that is done this way.

 

[rhunter73]

Re: Tohatsu 9.8 4 stroke lower unit gear oil check

Thank you both so much. I bought one of those little hand pump adapters for the lower unit on the way and topped it off before putting in. It was about 75 ML to "top" it off.

I just didn't want fry my lower due to too little gear oil; you never know if someone at the factory was having a bad day.

The 9.8 is a great match to my old 12 foot fiberglass boat; it actually got on plane and the kids loved it!

Thanks for all of you help.

 

[Sea Rider]

Re: Tohatsu 9.8 4 stroke lower unit gear oil check

9.8 horse uses 320 ML, so 75 Mil is near 1/4 less oil. The correct leg oil amount is suppossed to be checked by dealer before delivering engine, but seems nobody does so, will include myself. By filling less oil into each leg, the manufacturer assumes final user will change it inmediately after 10 hour break in period adding it's full lcapacity.

Happy Boating