I have a 2000 90 hp mercury 2 stroke and when going on plane sometimes the engine bogs down and is very slow to get on plane. Once on plane though the engine is good to go and has no issues. Other times the engine has no problems getting on plane. This mainly happens when the engine is cold but can happen sporadically throughout the day. Any thoughts on this I have my ideas but interested if anyone else has experienced this? Thanks in advance!
I had the same motor with the same symptoms a few years ago. It turned out to be an igniton module for one of the cylinders.
Did the dealer diagnose it or is it something I can look at and identify?? Thanks!
I had the same problem and it turned out to be not hot enough running plugs and had a sink and link on the carbs and it was better.
Take it in to a trusted quality Mercury Marine mechanic. Sometimes it is better just to have it looked at. It does sound like a carb issue though. Coils will generally get weak when they get warm or hot. A good carb synchronization may be in need. Check with a mechanic first.
I just had to replace my ignition module also.Sounds like the same thing I hadon my 90 Mercury
. 
I have the same motor… How much does an ignition module cost? Ours does the same thing.
The ignition module cost me $450.00
But that included labor for checking out the whole motor and changing the gear lube in the lower unit. also replacing a hose on the oil injection. Plus going through my 15hp kicker and lube the lower unit in it also.
I got a sweet deal 
on the boat so I didn’t feel bad sticking a few bucks in the motor. a 1992 Mercury with about 20 hours on it. 
I just got off the lake with the boat guy and the bog was in my card setting and he said if it would run wide open it is not in the ingition mod so hopefuly this will help you guys out but like he said ever motor is just a little diffrent
You must be logged in to reply to this topic.
