Oil leak

[Mariner Fan]

Steve, the oil leak is from the coolant reservoir. It’s the hose connected to the small nipple on the reservoir opening.

[videoarizona]

There is a drain hole in the water pump. Wouldn’t the oil drain out of it?

 

 

Not necessarily. The weep hole "may" show coolant but not oil. Regardless...the twinkie and the coolant pump are the two most common places for problems with oil in coolant. The twinkie also has the vent hose that @Du-Ron and I mentioned could be blocked...which still could be...but... I dont think is the case here. The twinkie (named because from the top it looks like one) is a heat exchanger...oil and coolant are only a tiny gasket away from each other. So any issues in the gasket will cause a mix.

 

I'm going to go with the pump, though. As Steve, @M61A1MECH said...there is a common shaft driving the impeller with seals to keep the oil/coolant separate. Those seals do wear. It's not a hard fix as everything is right there on the lower right side front of the motor. Get a cover gasket and take it apart. Info and pictures in the manual area and by searching the forum.

 

Either way...I would do both twinkie and pump before I would think of head gasket.

 

Suggest you go to the section that has the 2nd Gen technical info, then the parts diagrams area. You'll find the parts manual as well as the service manual there.

In the water pump section, will be a blown up diagram of the pump so you can get familiar with the parts.

 

hope this helps...

[M61A1MECH]

Head gasket issues normally show up in either a compression test or a leak down test, also any shop worth it's salt will have an exhaust gas analyzer, if there is blown head gasket I would expect oil or coolant to be getting in the combustion chamber and thus going out the exhaust, the analyzer will pick that up. I doubt very seriously if there is a bad head gasket, all most unheard of on these motors.

 

When my 98 Royal Star first exhibited the issue, the service manager and talked it over and neither of us had any good ideas except to look for a blown head gasket, that proved to be fruitless. So we looked at the two systems oil and coolant for common areas and came up with the water pump driven shaft and seal and the heat exchanger. There was no hint of oil coming out of the drip tube in space between the water pump and oil pump, but we decided to check that and sure enough they found a bad seal. The service manager with 20 years working on Yamahas had never seen that issue before.

[Mariner Fan]

So the offending seal on the water pump would be #7 oil seal?

 

[M61A1MECH]

So the offending seal on the water pump would be #7 oil seal?

 

https://www.venturerider.org/forum/attachment.php?attachmentid=117680

 

 

Yes , sort of, the mechanical seal #8 is allowing oil into the coolant, so you should change both. The shaft on item 2 maybe damaged also it needs to be inspected. And replace the gasket #16 .

 

You may find you cannot order the individual items and instead have to buy a kit that has items, 4, 5, 6, 7, and 8.