88 evinrude 90hp V4 exhaust cover leak

[ssmyth]

i recently did a carb rebuild, and cleaned the interior of the cover, and below the engine. i took it out for a test run and everything ran great. when i got back to inspect, i noticed some oily under the control cables, and the bottom of the exhaust cover. im trying to get all the leakys fixed. i cant locate where the oil came from under the control cables, as the only place wet is at the bottom of the exhaust cover in the rear. is it difficult to change the exhaust gasket, and does it hurt to run it until i have time to fix this?
had it tuned last fall, and compression was good. I dont think the head gaskets are leaking.

 

[Gary H NC]

Re: 88 evinrude 90hp V4 exhaust cover leak

Exhaust cover leaks are fairly common on those motors.

Mine was leaking when i bought it on my 81 175 motor.

I replaced the inner and outer cover gaskets,used aviation gasket sealer on the bolt threads and have not had a problem since.
Also the inside of the cover had heavy carbon build up so it gave me a chance to clean everything up.
You can also see the sides of the pistons and exhaust ports while you are in there.

Was not a hard job at all...

 

[ezeke]

Re: 88 evinrude 90hp V4 exhaust cover leak

Check the drain line between the bottom of the intake manifold and the air silencer, also check the gasket in the air silencer cover.

 

[emdsapmgr]

Re: 88 evinrude 90hp V4 exhaust cover leak

It is possible that the exhaust cover is leaking. On that flatback engine it is very easy to replace it. Prior to that, I'd double check to make sure the powerhead base gasket is not leaking-also a common problem with these engines. When these go, it is common to find exhaust gas leaking from under the powerhead-into the cowling. This usually is accompanied by some black goo/tar at the base of the engine. You might even have a small water leak. While this is not a fatal problem, this exhaust gas will get ingested into the carbs during normal running-probably not the best thing on a long-term basis.