[brownm16]

Hi All.
I have a 1988 mariner 200hp that has always ran fine/perfect until this last week. In this last week the performance has slowly deteriated. Harder to start, idle eratic and use to be 8 to 900 and now is 10-1100, sounds like it is missing a little and has an occasional cough, all the plugs look really wet, it is now very hard to get up on plane, really rough running when going slow in no wake zone. It even cut out on friday doing about 25mph and had to be restarted. It rev's up slow when not in gear:%.

Easy stuff I tried on the water.
I tried running off a portable tank to make sure it was not fuel and no change.
I tried new plugs and no change
I tried carb cleaner and no change
I opened up carb bowl screw to make sure each carb had fuel
I held my hand over each carb (choke) to make sure each one was sucking up gas.

I am pulling boat out next weekend. Any suggestions where to start first.

Thanks

[brownm16]

Originally Posted by brownm16

Hi All.
I have a 1988 mariner 200hp that has always ran fine/perfect until this last week. In this last week the performance has slowly deteriated. Harder to start, idle eratic and use to be 8 to 900 and now is 10-1100, sounds like it is missing a little and has an occasional cough, all the plugs look really wet, it is now very hard to get up on plane, really rough running when going slow in no wake zone. It even cut out on friday doing about 25mph and had to be restarted. It rev's up slow when not in gear:%.

Easy stuff I tried on the water.
I tried running off a portable tank to make sure it was not fuel and no change.
I tried new plugs and no change
I tried carb cleaner and no change
I opened up carb bowl screw to make sure each carb had fuel
I held my hand over each carb (choke) to make sure each one was sucking up gas.

I am pulling boat out next weekend. Any suggestions where to start first.

Thanks

Add: This motor does not have oil injection. serial # 6427305. hooked to a dual battery setup.

[brownm16]

HI,, any mechanics out there that could point me in the right direction..:^

[andy6374]

First off when asessing a motor that is starting to have trouble, start with the basics.

Check compression and make sure there is spark at all six cylinders.

The coughing is possibly due to a lean condition. This can be caused either by dirty carbs or an ailing fuel pump. Try squeezing the primer bulb when the problem occurs and if this cures the problem then it's time for a fuel pump rebuild. If not it might be time for a carb disassembly, soaking, blowing out and drying every orfice with compressed air and then reassembly with new gaskets.

[Kevin W]

ethanol based gas may have cleaned out your fuel system and deposited junk in the carb.

the new gas also pulls alot of moisture out of the air and the water forms at the bottom of the tank.

always make sure your vent is closed when not in use.

[andy6374]

Originally Posted by Kevin

ethanol based gas may have cleaned out your fuel system and deposited junk in the carb.

the new gas also pulls alot of moisture out of the air and the water forms at the bottom of the tank.

always make sure your vent is closed when not in use.

Great point. This is a good place to start. I forgot about the ethanol plague.8)

It will require some fuel system checks anyways.