Motor shooting water

Ok I feel like a complete idiot because I don't have a clue what to ask you. First I am a newbie with boats, and motors. My wife probably knows more than I do. I purchased a used pontoon boat with a 1999 Johnson 50 HP. When I put it in the water last weekend the motor ran great for the first 20 minutes. Brought it in took it back out and it seems that it was different. For some reason I could only push it to half speed. Each time I would try and open it up it would bog down on me. I had a few friend take a look and they all told me the same thing. The motor has been sitting up for awhile so there might be trash in it. Get some STP and run it and try and get any dirt out. I have done that and it runs ok when it is only half way open, but when I try to run it faster it bogs. Now today I took it out and I noticed that water seemed to be just shooting out from the motor in all directions. The water comes out the back of the motor where it is connected to the boat by some opening it looks like. If your are looking at the motor from the back of the boat it would be where the motor connect where onto the boat There is an opening it looks like with a flap. Water does not come out of that when I am just riding along at a slow or medium pace but when I open it up the water begin to pour out through that opening. It then goes back into the lake from what I can tell. The water splashes all the way up the side to where the cover connects and protects the motor. It just seems like there is way to much water going in different directions at the back. So any idea??????? I am sorry but I just know nothing about motors. Unsure about where to even take it to for service without getting taken to the bank. I live in Conroe Texas which is about 50 miles north of Houston. As I said the motor runs good and it starts right up every time, but can't run it open at all, and I know that much water should not be shoot up and running in different diretions. Thanks for any infomation you might can share with me.

Re: Motor shooting water

Welcome to iboats Exhorter !

At the top of the rear midsection you should see an exhaust baffle. You should see water and exhaust being expelled from the motor at idle. This opening relieves exhaust back pressure on the motor when it's idling. When underway, the exhaust is pulled down through the midsection and out , underwater, through the prop hub. All of this is normal motor operation. You should also have a 'tell tale' stream of water being ejected from the rear starboard side of the lower motor cover. This stream shows that the water pump is working.

As for the power loss, your motor has 2 carbs, one for each cylinder. If one of the carbs is blocked, no fuel goes to it's cylinder and you end up running on only one cylinder. This can be the cause of the power loss. Your motor can run on one cylinder at idle. Loss of spark to one cylinder can cause the same symptom too, running on one cylinder only. Have both plug wires checked for spark and carbs too.

Re: Motor shooting water

So then it is ok for the water to be shooting up midway onto the motor? I was told that was not good for so much water to be all over the motor. Thanks for your quick reply. I will go out there today and try and go over everything you posted to make sure I understand what it is you said.
More than likely it will end up in the shop, cause this guy don't have a clue:redface: Again thanks

Re: Motor shooting water

xcuseme described how it should be.......sounds like you've got a leak in there somewhere.

if you could post a picture showing where the water is coming from that'd be helpful.

best case scenario, the hose leading to the "tell tale" (see xcuseme's post) sprung a leak, it's an easy fix. It'd be a hose leading from the cylinder head to a nipple inside the engine cowling.

worst case, you ran it lean; one or both carbs hi-speed jets clogged or partially clogged, it doesn't get enough fuel. Not enough fuel also means not enough lubricating oil, leading to overtemp and hopefully nothing worse than blown head gasket.

get yourself a compression gauge, check the compression on both cylinders, let us know what you get.

order a couple carb kits (from iboats) and a service manual (aftermarket brand from iboats), or preferable your factory shop manual from marineengine.com or kencook.com

You can't clean clogged carbs without taking 'em apart.

Don't run it like it is until that's done.

almost forgot....welcome to iboats!

Re: Motor shooting water

If that boat sat for awhile it's very likely that some old varnished gas popped loose and clogged your carb jets. It's doubtful that any kind of gas treatment will clear that up. You could get lucky though. If you're at all handy around cars, an outboard carb rebuild will be mindbogglingly simple in comparison.

Re: Motor shooting water

Forget the STP. Follow jtexas's advice on the manuals & service. Also don't hesitate to take the cowl off and have a look see while it is running. If anything looks real odd post back here what you are seeing or take a picture - even better.