Mariner having starting problems in the heat

reelnmn

Cadet
Joined
Nov 30, 2011
Messages
13
I have a 1993 Mariner Outboard 135HP. First thing in the morning it still cranks over first or second time and purs at idle. However, as the day progresses and the temp gets higher (particularly over 85) it becomes more difficult for the motor to idle without dieing. Even after running down the lake at WOT if I shut down the engine at the dock to go get the trailer, it will start on the second or third crank but then die when I engage the throttle. It usually takes 5 or 6 of these attempts to get the boat on the trailer.

A few more details: approximately 13 years ago the oil pump failed and was removed with the reservoir - I now mix 50:1 oil straight into the gas tank; motor runs perfect in the cold; replaced fuel filter and spark plugs over a year ago; to my knowledge the carbs have never been cleaned.

Last summer I was on the lake and this was happening however this time it wouldn't start at all. After looking I noticed an air bubble in the top of fuel filter. No fuel because of this pressurized bubble of air. I disconnected the line from the pump, turned the key and the pump provided and adequate stream of fuel. Upon reassembly she started first time. This leads me to think something is sticking like a valve. Anyone have a suggestion to start troubleshooting?

Chris
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,420
Re: Mariner having starting problems in the heat

Chris, I have that same motor, but have never had that same issue. You might check to see if she is overheating. Have the 'stats ever been changed? How about the poppit valve or water pump?
 

reelnmn

Cadet
Joined
Nov 30, 2011
Messages
13
Re: Mariner having starting problems in the heat

No idea when the last time the stats were changed. At least 3 years...possibly ALOT longer. Water pump gets replaced each winter. I get a good pee stream and no overheat warning so I hadn't considered a poppit.
 
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