[slider]

I have a 175 Mariner. It is bogging down underload, when I throttle it up in gear in the water. I checked the spark and it was giving me minor spark on three cylinders. Two on one side, one on the other. I checked it again at 3000+ rpms and it had great spark at the higher rpm. I just had the carb rebuilt. I checked the plugs and they did look oily and had some carbon build up. Could this be my problem? What should I look for. Also compression is good and I premix the oil and gas. Thanks

[deedledog]

I know you just had the carbs rebuilt, but it sounds exactly like a carb problem I had a while back. Mine would idle OK (maybe a little rough, but hardly noticeable) and run fine with no load from 0 to max rpms, but as soon as I put a load on it it would die before I could get on top of the water. Good luck.

[CAPTBLACKSMARINE]

SLIDER YOU SAID YOU CHECKED THE SPARK AND ONLY HAD FIRE ON 3 CYLINDERS.HOW DID YOU CHECK IT? THE SPARK SHOULD JUMP A MINIMUM 3/8" GAP AT CRANKING SPEED IF IT DOES NOT YOU DO HAVE A PROBLEM.IF FIRE IS GOOD AT 300O RPM BUT NOT AT IDLE SPEED YOU PROBABLY HAVE A BAD STATOR THE MARINER STATOR HAS A HIGH AND LOW SIDE AND IT SOUNDS LIKE THE LOW SIDE HAS GONE OUT .I WOULD EITHER TAKE IT TO A TECH OR BUY A MANUAL AND CHECK THE VOLTAGE OUTPUT AT CRANKING SPEED.ALSO CHECK ALL OF YOUR GROUND WIRES AND BE SURE THEY ARE CLEAN AND TIGHT.ONE MORE THING MARINER IGNITION TEST HAVE BEEN KNOWN TO LIE ABOUT WHEATHER A PART IS BAD OR NOT BE SURE YOU HAVE A BAD PART BEFORE YOU WAIST MONEY ON A PART THAT CAN'T BE RETURNED.

[slider]

Capt Black. Thanks for the reply. I do get spark at low idle, but it seems to be a weak spark on three of the cylinders. How I tested was one by one pulling each wire off. First at low speed (which gave weak spark), then at 3000 + rpm(which gave great spark). I definetly don't want to go wasting money on parts I don't need, that's why I want to pin point the problem. Thanks