My opti started missing the other day, it's a spradic miss, and very rough. Dropped about 200 rpm, I checked compression and everything is good, put new spark plugs in and changed nothing. Anyone have any ideas?

Check your fuel system lines , filters and bulb.
Ethanol in the gas is probably eaten up and clogged your system.
Hope this helps.

thanks

Lift pump and fuel lines get eat up from the ethanol.

take it an have it hooked up to a computer dont take a chance the computer will tell where the problem is coming from

Sta-bil if you are not already running it. Mine did the same with this new gasoline. Ran rough and felt bogged down with less rpm's. I had never run sta-bil through it but when it started doing this, I tried it. Problem solved. Added the recommended amount to both gas tanks and ran for about 15 minutes before I felt a change. Ran low rpm's during that time and began to notice an improvement. Ran it at 3/4 throttel for about 10 more minutes and it cleaned up the fuel problem.

99' 200 Mercury Opti

Ryan what year model is your Opti. My 09 would do the same thing if i didnt run Sta-bil blue in it. I took it to the shop and they said the fuel wasnt burning hot enough so it would have a power loss every once in a while. My new motor from day one has had sta-bil blue in it no matter what the fuel make up is. never had a bit of trouble out of it since running the sta bil in either boat. Good luck

it's an 07, but I have not ever had this problem till the other day. I will try some sta-bil I just thought the ethyanol would not cause issues unless it sit in your tank, I run my boat almost every day. I will prob have to go have it hooked up to a computer.

The ethanol will eat anything rubber in your fuel syst. run stabil in every tank.

Mine is an 06 and bought it from a guy and the mercury fuel lines were breaking down inside of the line. It will get in your fuel filter and make it run Terrible eventually not getting hardly any fuel. My cylinder also seized up on mine and had to get another power head. Don't won't to scare you but you definatly need to get it checked out. Mine was running just fine as well then one day it just died and would go faster than an idle. Thank goodness for a warranty.

My 07 90 will not run without Stabil in every tank and I run at least ten gallons of gas through it every weekend

Be sure to check your fuel filter. It needs to changed annually when you service the foot. It is easy to change.

Sounds like a coil. Merc had some coil issues around that year model.

If it is a coil there has been a major recall. If it is the coils, get them all replaced and it's likely it will be covered by Merc.

Mine did the same thing. It was a coil. If anything, I would at least have it checked to be sure your coils weren't apart of the recall. They replaced all of mine and it was covered by Mercury.