motor bogs down at wot

R

rigoletsfishnfinatic

Cadet
Joined
Sep 1, 2009
Messages
11
i have a 1986 mercury 25 xd pull start tiller steer it starts easily most of the time but it bogs down at wot the warmer the engine gets the less the throttle will go with out bogging down .i replaced reed valves recently and that didnt do anything have carb rebuild kit coming tomorow .does anyone know whats wrong .oops i forgot it cranks and runs perfect on ear muffs
 
Barnacle_Bill

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: motor bogs down at wot

Either your high speed jets clogged up or fuel pump needs rebuilt.
 
J

Jeff_G

Petty Officer 2nd Class
Joined
May 1, 2005
Messages
179
Re: motor bogs down at wot

While it very easily could be a carb problem. You need to check both compression and ignition as well.
Check the ignition with a timing light, just look for steady bright flashes on both cylinders.
Never rev up a motor on the hose or in neutral, it must be in the water under load.
You can check it while on the trailer, just back it down into the water, warm it up, shift into gear and check at different rpm's.
 
Silvertip

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,762
Re: motor bogs down at wot

Did you fully disassemble and thoroughly soak the carb, make sure every passage was squeaky clean, adjust float level properly, adjust the idle mixture in the water (if adjustable)?
 
hkeiner

hkeiner

Lieutenant Junior Grade
Joined
Oct 17, 2006
Messages
1,055
Re: motor bogs down at wot

i hate this motor saving for a yamaha
Click to expand...

Mmm. Buying a new motor is one way to solve the problem, whether a Yamahoo or other brand motor. However, fixing your Merc should be easy and much less expensive if you follow the troubleshooting methods suggested above, as long as the compression on the motor is good. Keep at it using the good advice you get here on this forum. It has helped me solve some of my own frustrating problems in the past.
 
R

rigoletsfishnfinatic

Cadet
Joined
Sep 1, 2009
Messages
11
Re: motor bogs down at wot

ok got new plugs coils wires fuel pump fuel lines and filter .got 80 psi on both cylinders oh and carb rebuild kit could it be the stator or switchbox not letting it rev over lower rpms
 
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