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mercury 115 will not pull under load

B

bandit 115hp

New member
hi this seems common but i thought someone out there may be able to help..the weird part is that i took it out three days ago and she was going like a bullet..i pulled in to shore to pick up the kids and then headed back out pushed her out to full throttle and nothing i hit about 2200 revs and it stayed there..so thinking a cable had come loose i took her home and tested it out of the water it revved up fine in gear and out no miss fire the cables are fine ..i am getting full throttle so i took it out again and same thing under load its dead...please help as i am great with cars but this thing scares me.it just seems complicated...sean
 
And the model # of this moter is ????? Not complicated at all-----------------Most motors ( even in bad shape )running on a hose will wind right up on a hose.-This test proves absolutely nothing as there is no load !!-----------------So start with the basics.------Do a compression test and see if there is spark on each cylinder that will jump a gap of 7/16" or more.-----------------Most motors are damaged by operator error. Do you run with a tachometer ???----Do you have the correct prop ???----------Do you monitor the operation of an oil injection system if so equipped ???------Do you install a new waterpump impeller on a regular basis ??
 
You have the black stator?
Sounds like the stator went bad in the Hi-speed stage. The switch box probably got taken out, too.
 
ok yes its the black one ,,on further inspection i have noted that the wires running out of the stator are buggered as in the plastic shield is gone and they are corroded ..that being said it has good compression in each pot..great spark and it is not missing under load. i am currently rewiring the whole system ...as for engine year cant find a plate anywhere i only have the engine serial number 1518399,, but i suspect its early eighties ...now would it still run if the switch box went...thanks sean
 
i have rewired the system it now pulls out and gets to full revs..but it does take a bit to get on the plane...the wires from the stator are still not perfect so i am going to replace it..fingers crossed that will fix it...thanks for your help...
 
Sounds like you might have lost a cylinder. Causes for that are many: Bad plug, bad wire or coil, etc. You can localize the problem by recreating it, then reading the plug temperatures with an infrared temp gun (an indespensible boating tool).

Jeff
 
Is this an inline 6 cylinder with 2 switch boxes or what ?????----------------------Put a timing light on this motor on each wire and see if it is firing on all cylinders !
 
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