86 mariner magnum 150hp

[Leonard Ray]

I have a 86 mariner magnum 150hp that is hard to start. If give it a little throttle it will start.My bigest problems is when you put it on the water it start terrible and the throttle is lazy.It take about 4 second before it will take the gas (when you open it up) then runs great.But when you turn it off then it start terrible again.HELP

 

[aussieflash]

Re: 86 mariner magnum 150hp

Sounds like flooding or other fuel delivery problem.Check bulb not soft.May need fuel pump and carb service.

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Sounds like flooding or other fuel delivery problem.Check bulb not soft.May need fuel pump and carb service.

Thats kinda what I am thinking so I cleaned the carbs this weekend and it made no defferance.Do you know any way of check the pump withput replacing it?
Thanks

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Took the carbs off and cleaned them and then took the fuel line off and turned the motor out and gas sprays out 2 feet. Any body got any more ideas. Had someone say the stator, but I can't see that being the problem.HELP

 

[j_martin]

Re: 86 mariner magnum 150hp

Any guess as to parts without proper diagnostics is just that, a wild @@@@ guess.

Start with a compression test. Then test for spark (with a gap tester) Then fuel delivery, then timing and linkage. It's all got to be right for the engine to perform normally.

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

I did a compression check and all cyclinders where 50 .That sound alittle low.Everything else was good.
Not sure if my guage is right because the boat planes out great and has good power so i am going to get another compression check and make sure.

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Did a compression check with a new guage and all cylinders where over 110.Timing is right on the money.Put it in the water Sat. and it still starting bad but once i got it start it ran great ( throtle is still lazy). If you stop and let it idle it starts running bad after about a min. and shut off. So i am thinking it is a fuel problems what do you guy think?

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Can I check the stator with an oms or volt meter ?

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Can I check the stator with a oms or volt meter?

 

[aussieflash]

Re: 86 mariner magnum 150hp

You can check with ohmmeter.
You got a Merc Service Manual?If spark is good,id go back to fuel system.
Could be stuck float/needle seat or float level wrong.Bad Fuel Pump.Dirty filter.Anti siphon valve.Old gaskets carbs/reed block.
All of these will cause bad idle and hesitation on throttle.

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

You can check with ohmmeter.
You got a Merc Service Manual?If spark is good,id go back to fuel system.
Could be stuck float/needle seat or float level wrong.Bad Fuel Pump.Dirty filter.Anti siphon valve.Old gaskets carbs/reed block.
All of these will cause bad idle and hesitation on throttle.

Took the fuel line off and turn it over and it was pumping as much air as fuel. There was not a good stream fuel.

 

[Leonard Ray]

Re: 86 mariner magnum 150hp

Took the carbs off , put them in carb cleaner for two hours and rebuilt them. Spark is good on all cylinders,drained the fuel, took the oil tank off and cleaned it and changed the oil.All cylinders have 110 or better.Timing is good.NOW when you put it in the water it will not even start but with muffs and a water hose it will run all day.WHAT AM I MISSING HERE!