1988 90 hp Johnson V4 leaking oil

[moonman]

Finally got my boat out a couple days ago and it ran good. After I put it in the garage, a couple days later I noticed a little puddle of oil underneath the propeller. So I am guessing that there must be some kind of seal that is bad. Has anyone ever changed one of these? Can the average guy do it or is this something that should be left to a pro. I had changed the lower unit oil over the winter and it didn't look like there was any water in it.

 

[AEROCOOK]

Re: 1988 90 hp Johnson V4 leaking oil

What color is the oil?

 

[Will Bark]

Re: 1988 90 hp Johnson V4 leaking oil

If the oil is gray to black and smells "gassy" then it probably is unburned fuel oil mixture and is normal; check your gear oil for water tho.

 

[moonman]

Re: 1988 90 hp Johnson V4 leaking oil

If the oil is gray to black and smells "gassy" then it probably is unburned fuel oil mixture and is normal; check your gear oil for water tho.

Yes it was dark colored and smelled like gas.....this is my first boat so i am paranoid about everything. I will check the gear oil again. I changed it last fall-winter and it was good. Thanks for the replies.

 

[TD_Maker]

Re: 1988 90 hp Johnson V4 leaking oil

Mine does that too. It's unburned fuel/oil mixture coming out of the prop.

 

[johnson89]

Re: 1988 90 hp Johnson V4 leaking oil

check and make sure your firing on all 4 cyls.....I had a bad coil on 1 of my cyl. and it will cause this to happen,,,,

 

[boobie]

Re: 1988 90 hp Johnson V4 leaking oil

Don't worry about it. Check your G/C oil and if it's okay take the mtr out and run the heck out of it.

 

[moonman]

Re: 1988 90 hp Johnson V4 leaking oil

Forgive my ignorance on the following questions. How do I check to see if the coils are working properly? One of them looks a little worn. What is G/C oil? Gearcase?
Thanks guys.

 

[metriccrescentwrench]

Re: 1988 90 hp Johnson V4 leaking oil

Forgive my ignorance on the following questions. How do I check to see if the coils are working properly? One of them looks a little worn.

If the engine's running good I wouldn't worry about it. If you're paranoid and will lose sleep because someone on the internet said to check your coils you can purchase a variable gap spark tester from an auto parts store for around $15, set the gap to 7/16" and check for spark on each cylinder as someone cranks the engine.

What is G/C oil? Gearcase?

Yep. If you want to you can loosen the lower plug and drain a tiny bit of oil to make sure it doesn't have water in it. You can also remove the top fill plug and make sure the oil is up to that level.

But honestly, a little bit of unburnt fuel/oil coming out of the exhaust is normal.

 

[johnson89]

Re: 1988 90 hp Johnson V4 leaking oil

just check for spark I didn't mean to imply that you had a bad coil,that was one of my problems,,,if 1 cyl. is not firing good that unburn fuel will show up at the prop.

 

[moonman]

Re: 1988 90 hp Johnson V4 leaking oil

My gearcase oil looks good. I think I will invest in one of those spark testers and check for spark for my own piece of mind. Thanks for your replies.

 

[metriccrescentwrench]

Re: 1988 90 hp Johnson V4 leaking oil

If nobody has mentioned it yet you ought to find yourself an OMC service manual specific to your engine. Used ones can usually be found on ebay for $30 or $40 and are well worth it.

 

[moonman]

Re: 1988 90 hp Johnson V4 leaking oil

I have been trying to find a manual but the only one that I found was over $50.00. Bought one of those Seloc manuals and it isn't detailed enough.

 

[metriccrescentwrench]

Re: 1988 90 hp Johnson V4 leaking oil

I have been trying to find a manual but the only one that I found was over $50.00. Bought one of those Seloc manuals and it isn't detailed enough.

I wouldn't think twice about paying that for the OMC manual. You'll save more than that the first time you change a water pump impeller yourself. As you've found out the generic one-size-fits-all manuals leave a lot to be desired. The reprints from outboardbooks cost more than that, and apparently people are paying that because they're still in business.

 

[moonman]

Re: 1988 90 hp Johnson V4 leaking oil

The spark test came out good for all 4 coils. Like boobie said, " I am going to run the heck out of it".