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1987 Mercury 25 HP 2 Stroke warm up problems

M

malibu7902

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Hi new boat owner/forum member. I have a 16 ft alum. bass boat with a 25 hp 2 stroke. Serial # is B172473. From what I could find it is a 1987? Any way the prob. I am having is it takes 10 to 15 minutes to warm the motor up. When its warm it runs great as far as I can tell. Lots of power very fast out of the hole. When cold runs only half or third power. Sounds like the motor is bogging down. It has a fresh carb. rebuild. New reed valves. New plugs. I also went to change the thermostat and found none installed. It has one now, but it did not help the problem. Any help appreciated. I am new to outboards and don't know where to look next. Thanks.
 
While I was out there I tried messing with the throttle with the cover off while it was warming up. It seems like it could use a little more throttle when in fast idle. Also when warmed up the idle needs to be adjusted. It wont idle. If anyone can explain how to do this the proper way I'd appreciate it. Thanks. Also what is the most common cause of a high rpm misfire. I'm not sure but I think it misfires at high rpm. Also found my primer bulb is not pumping up to firm, so I am going to get a new one this morning.
 
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A motor in good condition would warm up in about 1 minute.--------------So time to find out your running issues.-----Compression test and a strong spark test is required here.
 
I just bought the spark tester. The compression test is going to have to wait till I buy the tool or get the boat by the shop so I can use theirs.
 
Just did the test and no spark on the lower cylinder. The top is blue and jumps the 7/16 gap no problem. Does that mean I need to replace that coil? Or is more diagnosis needed?
 
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