25 mercurey need some help

[hunt4life69]

i have a 92 model 25 mercurey and cant seem to figure out why it cuts out above 1/4 thottle .at the house running it with the water muffs on it back fires throught the prop above 1/4 throttle mabe every 15 seconds and in the water running it it seems to just load up or bog down either way i have had the carb off thinkig trash nothing new tank /hose/ bulb diaphram in fuel pump. i dont no where to look next. also if you take the top plug wire off at idle you can tell theres a miss there, if you take the bottom wire off the motor dies. any help is appreciated. craig

 

[kaferhaus]

Re: 25 mercurey need some help

have you checked the compression? Is the timing advance/throttle roller aligned properly?