9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

robin3547

Cadet
Joined
Jan 21, 2010
Messages
8
I have a 1987 4 stroke Yamaha, 9.9 hp. I bought it as a winter project as it is pretty beat up. I put oil in the oil pan and it just flows right out of the bottom of the lower unit. Is there anyone that can confirm that I feel the oil pan is cracked or is there something I am overlooking--thanks
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Did you buy it without running the motor?
Is the drain plug in?
Is the oil filter on and tight?
 

Grant Brown

Petty Officer 1st Class
Joined
Mar 13, 2004
Messages
390
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Hi Robin,

I just got a 1987 9.9 4 Stroke that does a similar thing. It leaks like crazy when I lean it on its side. If you find anything out, be sure to post a follow up. I'll do the same.

Grant
 

sdsaw

Petty Officer 2nd Class
Joined
Aug 19, 2007
Messages
188
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

I took the powerhead off and I am going to replace the seals and gasket. I should have the parts in a couple of days. If that works I will let you know. Bob
Did you also pull out the oil tank that is underneath the powerhead?

...Speaking from experience, I'm thinking that the oil leaking problem may lie around the oil tank (possibly from corrosion if used in saltwater)
 

Grant Brown

Petty Officer 1st Class
Joined
Mar 13, 2004
Messages
390
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Well I fired mine up on the weekend and holy s**t did it start puking oil!

I already bought an older Honda 4 stroke that has no issues so I put the Yam on craigslist and sold it as a parts motor to the first guy who looked at it.
Problem solved...
 

robin3547

Cadet
Joined
Jan 21, 2010
Messages
8
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Did you also pull out the oil tank that is underneath the powerhead?

...Speaking from experience, I'm thinking that the oil leaking problem may lie around the oil tank (possibly from corrosion if used in saltwater)

I am going to give that idea a test . I will pour some oil into the pan up to just below the powerhead mount, if it leaks, then thats the problem . If it does not then it was the power head gacket. thanks and I will let you know-Bob
 

robin3547

Cadet
Joined
Jan 21, 2010
Messages
8
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Well I fired mine up on the weekend and holy s**t did it start puking oil!

I already bought an older Honda 4 stroke that has no issues so I put the Yam on craigslist and sold it as a parts motor to the first guy who looked at it.
Problem solved...

Where was the oil puking from? Mine is leaking out of the prop exhaust port-thanks Bob
 

robin3547

Cadet
Joined
Jan 21, 2010
Messages
8
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

Did you also pull out the oil tank that is underneath the powerhead?

...Speaking from experience, I'm thinking that the oil leaking problem may lie around the oil tank (possibly from corrosion if used in saltwater)

You hit the nail on the head, I poured a cup of oil into the pan and out it comes.
 

robin3547

Cadet
Joined
Jan 21, 2010
Messages
8
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

You were right--Does the lower cowl have to come off to get the pan out?-thanks
 

sdsaw

Petty Officer 2nd Class
Joined
Aug 19, 2007
Messages
188
Re: 9.9 Elth-1987 4 Stroke Yamaha-leaks Oil

You were right--Does the lower cowl have to come off to get the pan out?-thanks
No, the pan lifts out the cowl which is one piece.
In fact, you have to remove the oil tank to remove the cowl!
If that makes any sense :D

Here are some pictures of the old parts that got replaced on mine.
Be prepared to spend some $$ on new parts, seals and gaskets.
I spent $700+ back in 2001
The factory repair manual is a must (#LIT-18616-FT-99) which is for my 1988 FT 9.9ELG

Top view of the mid-section
99midsection.jpg



Upright view of the oil tank assembly
When viewing from the top, you will have to remove the bolts around the perimeter (maybe 6?)
The bolts that are towards the middle, hold the oil tank to the powerhead base plate
oiltankassemblyupright.jpg


Upside down view of oil tank assem.
The left threaded hole is the oil drain
The large right hole is for the stainless exhaust tube which runs up the middle of the tank
The rubber grommet in the lower right is for the cooling water tube
Since your oil leaks out so quickly, I suspect the problem to lie in this area.
oiltankassemblyupsidedown.jpg




I attempted to repair my old oil tank by welding and JB Weld (to fill where it couldn't be welded) but decided to buy new replacement parts instead
repairedoiltank.jpg



Here's a parts breakdown of the parts
Look at the "upper casing"
http://www.yamaha-motor.com/outboard/parts/home.aspx

Good luck,
Scott
 
Top