25 mariner problems

[austinmichael]

I am new here but I would like to jump right in. I have a 1986 zodiak futura with a 1978 mariner 25. I had the motor running ok last year ( it would die if i let it idle for too long). This year i got it started but it died after about 10 seconds, then the next time i started it it revved really high and ran that way for a second before I hit the kill switch. I am pretty sure some fuel got into the carb to make it rev like that in between the two starts but I can not get it to run smoothly. How do I tune this? I am a v8 guy so I know my way around engines but the simplicity of my mariner and my inability to tune it have me baffled. I have tried cleaning everything and turned what I assume is the air/fuel mixture screw every which way, yet it is all to no avail. Do any of you have any suggestions before I take it to someone and shell out a few hundred bucks for something I should have been able to do myself? Thanks in advance, Austin

 

[Plainsman]

Re: 25 mariner problems

Welcome to iboats!!

First I would suggesting getting a manual. I don't think just turning things will help you.

For the mixture adjustment on the carb, seat the screw lightly, then back it out 2 turns. Better to have it a little rich, then to lean.
Do you know the last time the carbs were cleaned?

 

[austinmichael]

Re: 25 mariner problems

I know I need a manual, I was just putting it off. I turned the mixture screw all the way in and backed it out 1.5 times as I would with any other engine. I cleaned the carb last year and again yesterday.

I have been doing a little reading and think maybe my problem has something to do with the stator. I cleaned the fuel pump and everything in the induction system looks fine. I have adjusted everything but the ignition. The whole ignition system is completely new to me. I have dealt with ignition and timing before but again that was in small block fords, not 25 horse mariners.

Any other ideas? How do I verify if the stator is good or bad? How do I pull the cover or whatever it is called (probably some sort of a balancer) off of the top of the ignition system to get to the stator? I am thinking about using a harmonic damper puller and three bolts to pull it off since the nut is off the end of what I assume is the crankshaft and I can't get it to budge with elbow grease.

 

[Harker]

Re: 25 mariner problems

Sounds like it is sucking air to rev high like that. I don't know that a stator would cause a problem like that. Get a carb kit and clean your carb really well.