Optimax 115HP engine does not go to full power

[frankielegal]

I have an Optimax Mercury 115 HP 2009 engine. The engine used to start strong right away with no problems. I let the boat sit on my lift for three months without starting it. Now,it doesn't start right away, it idles very rough. When it does warm up, it doesn't reach plane speed even at full throttle.
I changed the fuel filter, any suggestions or help would be appreciated. Thanks Frank

 

[Bamaman1]

Re: Optimax 115HP engine does not go to full power

Modern 90/10 gasoline has a tendency to break down very quickly--producing a rubber eating acid. If you're going to leave your boat very long, run all the gas out of the carb, and keep minimal amounts of gasoline in the tank. Try using Stabil, and get rid of all that old gasoline to start with. Then, fill up preferably with 100% gasoline.

How do you say, "Help me Mr. Dealer?"--if you continue with the problem.

 

[frankielegal]

Re: 08 Mercury Optimax 115hp Lugging

Re: 08 Mercury Optimax 115hp Lugging

will the mercury optimax 115 hp run with only 2 out of 3 cylinders firing??? I think that is happening to my engine, top rpm is 2600, engine is a 2009, could one of my cdi coils be bad, thanks for any heklp, frank

 

[QC]

Re: 08 Mercury Optimax 115hp Lugging

Re: 08 Mercury Optimax 115hp Lugging

Hey frankie,

I moved this post ^^^^^ back to your thread. This will bump it to the top and maybe get you some help. Tacking onto that other thread ultimately confuses people and will mess you up. Good luck with this!!!!

 

[brandon110]

Re: 08 Mercury Optimax 115hp Lugging

Re: 08 Mercury Optimax 115hp Lugging

sounds to me like you have phase seperated gas. even with fresh gas if it sits for 3 months it will go bad. to check it remvoe you fuel water seperator and dump it out into a clear jug and let ti sit for about 5 min. what you will see it a a clear deffination between the 2 chemicals. if this is happing you need to have the tank pumped and all fuel cleaned out of motor. Very common problem i have done this to coutless boats. the new gas is junk. best thing you can do is before you plan on not using the boat for an extended amount of time is to run as much gas out of the boat as you can and the last time you use the boat dump stablizer in the tank and run it through. although this helps it isnt going to deffently keep it from happing agian. write your senator e10 is bad e15 will be real bad.

 

[aussieflash]

Re: 08 Mercury Optimax 115hp Lugging

Re: 08 Mercury Optimax 115hp Lugging

Id never put e10 in a outboard.But in Australia we have a choice of 91+e10,95oct and 98oct.
Check for spark on all 3.Pull plugs and inspect.If you dont have merc manual...get one.

 

[QC]

Re: 08 Mercury Optimax 115hp Lugging

Re: 08 Mercury Optimax 115hp Lugging

Our octane is a different measurement her in the US. Be careful about this guys ^^^^^^ Just needs to be clear how you're counting.

 

[hutch24]

Re: Optimax 115HP engine does not go to full power

ok, I have a 1996 procraft with a V 200 mag. EFI mariner. I have had it to the mechanic and it still not fix. Let me give you a little history. The boat will run great off the trailer. when I stop to fish and and start it up everything is fine until I push down on the throttle It will go to 2000 rpm and thats it. It will run fine and and will not missd at all but it will not go past 2000 rpm. The mechanic has changed the plugs changed the fuel filter, rebuilt the fuel pump, done a compression check has 130 on all cyclinders,check spark, check for water in the gas, checked fuel pressure, 36 psi and pulse pump 2psi, . I have had lots of experience with big block chevys but not with boat motors. It sounds like it it on a rev limitor. When i unload it off the trailer it will run like a new one. but when i start it back up it run and wont miss it just wont go past 2000 rpm. Can you please help. Thank you very much.