1988 90hp mariner fubar

Well after buying a 1988 Sea nymph 19'GLS with a 1988 90 hp mariner on it the excitement is gone. Did all the usual stuff of replacing lower gear lube checking oil in the oil injection tank, then started on the muffs. Everything was good. Went to the lake and no power. Discovered back at the shop that the carb sync linkage was broken. Neighbor has a machine shop and built a new one getting rid of the plastic one. Well took to the lake last night and took off. Ran like a striped a.$@ ape. Then started acting funny and shut down. Well. I think the auto oil system didn't oil. After sitting for about five minutes it turned over. There is a button by the oil tank and I remember everybody pushing it wondering what it does. I am going to soak the cylinders down with oil but I have a feeling I am in for an overhaul. Any insight would be great or suggestions.

Re: 1988 90hp mariner fubar

That sucks. Do you think you might have had an air bubble in your oil line?

Check compression/leakdown. Find out where you're at before tearing into anything.

Re: 1988 90hp mariner fubar

Did you rebuild/replace the WATER PUMP?

Run them without oil and they don't usually ever start again.

Overheat and stick a piston and after cooling off they often run again, but never as well as before until new pistons and rings are installed.

Test the alarm system, disconnect the temp sensor one the engine, key ON, ground the wire, hopefully the alarm sounds, if not, find out why.

Re: 1988 90hp mariner fubar

What is the button by the oil tank? The engine was peeing out water like a drunk on saturday night. But no I did not replace the water pump/impeller. I am going to pickup a new used trailer tomorrow. After I set the boat on it tomorrow night I am going to spray oil into the cylinders and then run off a nurse tank that is mixed 50/1.

Re: 1988 90hp mariner fubar

Also, how do you run a leak down test. The guy who worked on my Honda 90 said that is the only true way to run a compression test.

Re: 1988 90hp mariner fubar

A picture would help with the button.

As for a leakdown test, there are descriptions of the procedure all over the web. A leakdown test tells you how much pressure is lost in the combustion chamber. You have more ability to pinpoint where pressure is being lost with a leakdown test, particularly in four-strokes. If you're simply concerned with having potentially burnt a piston down, a compression test will likely give you the info you need on an engine with multiple cylinders.