Mid 80's 25hp LS....Won't stay running

[wall_guy_101]

Alright,

Last year my motor was getting progressively harder to start. Now it won't start at all. I've put in a new carb kit,jets have spark but my plugs seem excessively wet. Flooding out? Perhaps float adjustment?....need recommendations cause it's driving me nuts. It will spit and sputter but just can't get it to keep on keeping on.

Thanks.

[jeffreyd]

fuel filter, carbs rebuild, replace fuel lines, etc, it sounds fuel related

[VMS]

Sounds like it is time to replace the plugs. Then, when you get it going, do a hard shot of sea-foam through the carb throat, get it in there until the motor dies, then put a bit more in, let it sit for a spell (20 minutes minimum) then take it out and run it wide open until the whole system is cleared out.

To me, it sounds like plugs are fouling out, and the system just needs a good decarbonizing.

Steve

[BoxMN]

Wow, what happend to the search function on this board? I can't do a specific search... so... I tried to search a thread I had going and all the steps I did. Mine was remarkably similar to yours, and I think it would help you out, if anybody can find it.

BoxMN was posted, and it was about in April of this year. Good luck finding it... maybe my problem finding it is related to my IE8 issues with this board. I jsut wanted to post the link to my thread.

[Arctic Cat Pete]

Old gas?

[wall_guy_101]

Old gas is definitely not the problem....made sure to empty and clean tank and also ran non-oxygenated 91oct. fuel. The plugs were brand new a week ago so i have to eliminate that as an issue. I have to think it may be a stuck needle?? Perhaps it's not seating all the way letting to much fuel in. Will keep you updated and thanks for the responses!!

[VMS]

something cheap you can try: Replace the plug wires. Over time, the plug wires will eventually lose their capability to carry a current due to build-up of of resistance in the wire. Shouldn't cost more than a few $$ and is good preventative maintenance. Being a mid 80's motor, it certainly couldn't hurt...

tough thing is that it's like shooting in the dark.

What brand motor?

[Black_Bay]

Is this the thread Box? http://www.fishingminnesota.com/forum/ub...at_#Post1864221

[BoxMN]

Yep, thanks Black Bay, that is it.

You will see the mistakes I made and the little things to check. All in all, everything was easy on my motor, just make sure to check every detail to make sure you did things right.

Now it is "running like a Mercury"

[wall_guy_101]

Thanks so far for the responses!

I tore apart the carb today (again) with no better results. It looks like i'm getting a very good solid spark. Im beginning to believe it may be an electrical issue such as timing. It is a mercury by the way. The plugs are still wet looking even though I turned the needle way down. Still spits and sputters but can't get it to stay going. Will try the new wires but my mind is telling me it's something different. Still not sure what though. Another thing i'm encountering is after so many pulls today i'm getting really black oil dripping off of the bottom of the motor.......What next?? Perhaps it's the crank seal??....thanks again.

[swamptiger]

Sounds to me that you have the opposite of BoxMN's problem - too much fuel..

Which would point me back to the carburetor if you have good spark. If your float is made of a sponge-like material, sometimes they will get soaked with fuel, and when that happens, they won't float up and shut the fuel supply off like they are supposed to...

[wall_guy_101]

Afraid thats not it....its the hard plastic bladder style....

[jeffreyd]

if you take the float out and shake it does it have fuel in it? Have you checked the oil level to make sure that it is not making oil by pushing gas into the crankcase? We have this on some smaller equipment when it sits with the valve on, it seeps into the crack case then wont start. Just a thought.

[swamptiger]

Still think your getting too much fuel some way - needle valve not closing all the way or float not adjusted right, or something on that order.

Does the motor have good compression?

[eurolarva]

Not familiar with that motor but if it has a fuel pump maybe the diaphragm is shot. Is there a primer bulb? If so does it stay hard.

[twostroke]

did you check the compression with a tester you need at least 85 psi or its not going to want to stay running.

[boatfixer]

Euro has a great suggestion in the fuel pump. If the diaphram is shot, it will pump gas directly into the crankcase.

[wall_guy_101]

Again, thanks for the replys.

The bulb is staying hard so i'm not tending towards that idea. I'm now thinking towards the crankshaft seal itself. Will check compression tomorrow. Thanks again

[wall_guy_101]

Hey gents,

After almost a total tear down of the motor i seem to have found the problem(s). #1 Found a slight tear in the vacumm line thatruns from the top of the head around to the intake port. #2 My fuel line bracket was tweaked not allowing it to stay forward enough to start while in the neutral position. Seems to run like a honda now. Thanks again for the responses.

[BoxMN]

Hey gents,

Seems to run like a honda now. Thanks again for the responses.

You mean it is now running like a Merc hehe, my "real" boats have Mercs...

Glad you found it! Have fun