Pontoon Boat & Deck Boat Forum

yoooo alll....
Got a friend with a (guessing 1995) 115 2-stroke merc outboard, and when ever he trims up to trailer position, the 2 stroke oil leaks out of the cap.

Appears to be a design flaw?
Anyone else seen this?
any fixes?

My motor Walt but I got no tank. I premix sorry.

On my old 90 merc it had a hatch in the top of the cowl for the oil tank. It had a wire that fit in like a keyway to hold the cap firmly in place. Just moved the wire down to remove cap to fill.
doc

Missing gasket in the cap?

mines does the same, tried fiddling with the cap and still.
it stopped when it leaked below the bottom of the cap
-bb

I is all coming back to me now. I do remember that with my 2 stroke Mariner/Merc
I figured out not to fill the tank all the way if I was going to tilt the motor. Usually I was on a lift so I had no reason to tilt it.

I even towed it down. The pontoon sat high enough on the trailer that I was not worried about dragging it.

You can try replacing just the o-ring on the cap however, more than likely you will have to replace the entire cap assy to stop the leak.

LTB how you been!

So How fast does the twin run now?

I think you should post pics for the newbs!

I noticed that my 90hp 2 stroke ( which is physically the same as the 115 externally) the 2 stroke oil reservoir cap doesn't seal the best. I never have tilted my motor up further than just to trim while cruising around the lake, so I can't help you on the full up trim leaking cap scenario. I would just do like Greg said, and not fill up the reservoir to the top. I think I only go through a tank of oil about every 2-3 fuel tanks, so it doesn't go down fast. Plus, I always keep some extra oil on the boat, just incase it starts leaking or using it faster.

Whats new Curtis? I've been busy man...between work and getting my tunnel boat dialed in and havent had much time to work on the pontoon. So far I've seen 34 mph out of it which is pretty good considerin I dont have lifting strakes...i'm gonna get going on it again soon..maybe a 3rd engine. How is your boat running?

As for the oil leak... usually what happens is the plastic portion of the cap(yellow) gets weak or the threads strip...then it wont or cant compress the oring when you tighten it...so it leaks. You should be able to trim it all the way up without a problem. You can buy the complete cap assy from any Merc dealer for about 30.00 I think.

Thanks Gang!

.... a third engine on a toon.... sweeeeet..

[quote="LTB Racing"]Whats new Curtis? How is your boat running?quote]


its been better!

viewtopic.php?f=2&t=6442

Hopefully get the sei next month.