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1957 Evinrude BigTwin 35 Model 25028 has oily output


I just joined Smokstak because it helped me find out more about my "new" '57 Evinrude Model 25028 (like that it needs 24:1) which I recently bought to replace my '73 Johnson 65hp that developed a quarter-sized hole in its crankcase and will now run only if I hit the primer bulb every 30 seconds (too inconvenient for watersports). I also know very little about outboards and hope to learn a lot from this community.
So here's my introductory question: WHAT DOES IT MEAN WHEN A RUNNING ENGINE DEPOSITS A LOT OF OILY/GREASY BROWN YUCK INTO A WATER TEST BARREL? My Evinrude was supposedly winterized 3 years ago (not run since), so I'm hoping this oily stuff is just fogging oil residue and/or normal exhaust products. On the other hand, this yuck is draining out out of the rear port below the cowling: is this more indicative of a serious lower unit issue? (Either way, I don't relish the idea of my motor putting this yuck into the pristine waters of my favorite N. Idaho fishing lakes.) Thanks for any answers you guys & gals can provide!



do a compression test,mite need rings and pistons,check the head gasket for leaks from water jacket,and old outboards impellers wil get crispy and take a crap,its there good luck...

---------- Post added at 11:09:15 PM ---------- Previous post was at 11:04:45 PM ----------

remember its coming out your exhaust,its a 2 stroke and you wiil get some oil out but not that much or nasty,make sure u check the water jacket

Andrew Mackey

Last Subscription Date
Several comments for you. 1) check the lube in the lower end. it should look like a light grease or heavy oil, not milky and white. If it (the lube) is clean, you are good. if milky, you need to replace seals and change the lube to a fresh batch. 2) As for oil in the exhaust - 24:1 still is a bunch of oil compared to modern engines which use 50:1 or leaner mixes. You will get an oil sheen from your engine. Remember, running in a barrel concentrates the exhaust oil. In a lake or pond, there won't be much at all. if the engine was charged with oil before storage (fogged), then that oil will also be thrown out the exhaust until it is totally burned off. 3) what oil are you using? If SAE 30 NON Detergent, you might switch to a modern marine 2 stroke oil. Your engine should be able to digest it. If already using modern OIL, you should be OK. 4) There should be a discharge port for cooling water on your engine. When running, make sure water discharge is steady and full stream out the port. If the discharge is choppy or weak, then the rubber pump impellor needs to be replaced. A good marine shop should be able to get parts like seals and the impellor if needed

What ventilated the case on your other engine? if just corrosion, it can be sealed with a patch and some epoxy, like JB Weld. if the cause was mechanical (thrown rod), then you are SOL:(