mariner 115 running rough

[fatmoose]

I have a 82 mariner 115 I6. I purchased it with my boat a few weeks ago.

So here is the problem: It's very hard to start, it idles fine when it finally starts. It Bogs down when I push the throttle. If I let off and thrust it to full open it moves fine.

What I've done: Rebuild the carbs, fuel pump, all gas lines, spark plugs and wires.

Result: Still runs bad and is hard to start.

I am leaning towards replacing the stator but don't have the equipment to test the current one to see if it's bad.

Anyone have any suggestions or idears?

 

[spicoastie]

Re: mariner 115 running rough

A quick way to test your stator is just to ground your plugs out on the head and check the spark. Make sure not to hold on to the plugs while cycling the engine. As far as the bogging, does ur engine have air/fuel adjustment screws on the side of the carbs or are they pre-set. To make sure that you are getting correct fuel, run your engine and use a timing light to look in each carb and you should be able to see the fuel spray. Hope this helps a little

Brett

 

[fatmoose]

Re: mariner 115 running rough

Yes, it does have the adjustment screws. I'll be sure to test fire the plugs. Thanks

 

[spicoastie]

Re: mariner 115 running rough

Screw your adjustments all the way in then back out 1 full turn and then a half on all the screws and test again. Most of them are set at this setting.

Brett

 

[fatmoose]

Re: mariner 115 running rough

I have inspected the carbs and adjusted the screws. There is spark and good compression. I still cant get it to run. I am not sure exactly how to test the fuel pump to check it. I unplugged the upper fuel line that connects to carb 1. I cranked the engine and nothing came out of the pump. When I primed the bulb gas flowed out. Is there an issue with the pump or is there a vaccume that I disrupted?

 

[75TowerOfPower]

Re: mariner 115 running rough

When was your last compression test?

 

[spicoastie]

Re: mariner 115 running rough

your fuel pump should pump in strong spurts when you are cranking the engine

 

[fatmoose]

Re: mariner 115 running rough

Thanks, I think I have narrowed it to a diaphram issue.