Notices
The Boating Forum

90Hp Mercury Optimax NEED HELP

Old 08-17-2019, 09:58 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Aug 2019
Posts: 2
Likes: 0
Received 1 Like on 1 Post
Default 90Hp Mercury Optimax NEED HELP

What's up guys,

I have a 2010 90 Hp Mercury Optimax 2 stroke outboard that is starting to give me trouble. This boat was given to me 2 years ago by my uncle, who had a mechanic maintain it over the last 8 years Recently on the past two runs we had the engine would bog down and lose a sufficient amount of power, out of nowhere the power would return but then it would be lost just as quick. We thought it was maybe it was some water in the fuel so we put in some starton in the but the problem persisted. The engine started fine, but never got enough power to come up on plane and the engine continued to stall out several times on the way in. We are guessing it is a fuel issue but we are not sure on where to start. I can't seem to find a water seperator on this boat,It's a 2010 Bayliner, Any help is appreciated, Thanks, Guys!
Old 08-18-2019, 02:23 AM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Mar 2004
Location:
Posts: 403
Received 7 Likes on 6 Posts
Default

Check your fuel lines. Sometimes the inside part of fuel line collapses and robs the engine of fuel. Then check fuel pumps
Old 08-18-2019, 03:24 AM
  #3  
Senior Member
 
Join Date: Apr 2009
Posts: 602
Received 242 Likes on 133 Posts
Default

Well if pouring in starton didn’t fix it it’s time for a new motor!!!!!
Old 08-18-2019, 03:42 AM
  #4  
Admirals Club Admiral's Club Member
THT sponsor
 
Join Date: Apr 2013
Location: Baton Rouge, LA
Posts: 7,468
Received 2,959 Likes on 1,405 Posts
Default

Ignition coil.
Old 08-18-2019, 06:58 AM
  #5  
Senior MemberCaptains Club Member
 
Join Date: Jun 2003
Location: augusta, ga beaufort, sc
Posts: 742
Received 56 Likes on 33 Posts
Default

Run it on an 3 gallon external tank and see if quits bogging (don't forget to add some oil to the gas, not sure how the optimax mixes gas/oil). Squirt some of your fuel into a mason jar and see if you have trash or water in it. That will eliminate fuel contamination and/or delivery issues, from the tank anyway.
Old 08-18-2019, 07:02 AM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Apr 2012
Location: West Coast of Florida
Posts: 380
Received 130 Likes on 84 Posts
Default

Originally Posted by brownman View Post
Well if pouring in starton didn’t fix it it’s time for a new motor!!!!!
NO doubt!! He should have used StaBil 360 and I'm positive he would have had success!! Or the ever famous Seafoam would have fixed that coil!!
Likes:
Old 08-18-2019, 08:46 AM
  #7  
Admirals Club Admiral's Club Member
 
Join Date: May 2018
Posts: 298
Received 42 Likes on 36 Posts
Default

Check the filter in vst and see if any junk in there. Also check fuel/air psi on rails and see what those are.
Old 08-18-2019, 10:12 AM
  #8  
Senior Member
 
Join Date: Aug 2016
Posts: 1,680
Received 539 Likes on 346 Posts
Default

First thing invest 150$ and get a good racor filter setup and new fuel lines.Its a Boat and will get some water accumulation in the tank. and since the water is heavier than fuel the first thing headed down stream is the water. and fix the coil
Old 08-18-2019, 10:19 AM
  #9  
Senior Member
 
Join Date: Feb 2016
Location: Southeast Tx. Goodrich
Posts: 675
Received 501 Likes on 207 Posts
Default

Check your battery and wiring. All connections. Check battery voltage. These are power hungry engines. Make sure battery is at least 1000 cca.
Old 08-18-2019, 12:56 PM
  #10  
Senior Member
 
Join Date: Apr 2009
Posts: 602
Received 242 Likes on 133 Posts
Default

Pics of the wife!!!!!
Likes:
Old 09-18-2019, 01:27 PM
  #11  
Senior Member
 
Join Date: Jun 2016
Posts: 242
Received 55 Likes on 36 Posts
Default

Try to hook up to a separate small outboard fuel tank and run it. My Optimax 225 has a mixture of 100:1, so I'd think yours maybe the same. Also, replace all fuel and oil filters to see if that improve. Seafoam is good to clean the engine, but only use it in a separate small fuel tank.
Old 09-19-2019, 03:50 AM
  #12  
Senior Member
 
Join Date: Feb 2016
Location: Southeast Tx. Goodrich
Posts: 675
Received 501 Likes on 207 Posts
Default

Originally Posted by stevechumo View Post
Try to hook up to a separate small outboard fuel tank and run it. My Optimax 225 has a mixture of 100:1, so I'd think yours maybe the same. Also, replace all fuel and oil filters to see if that improve. Seafoam is good to clean the engine, but only use it in a separate small fuel tank.
Dont premix an opti. Bad things happen.
Likes:
Old 09-19-2019, 02:20 PM
  #13  
Senior Member
 
Join Date: Jun 2016
Posts: 242
Received 55 Likes on 36 Posts
Default

Originally Posted by Fishman39 View Post
Dont premix an opti. Bad things happen.
That's good to know.
Old 09-19-2019, 02:34 PM
  #14  
Senior Member
 
Join Date: Apr 2011
Posts: 3,258
Received 975 Likes on 410 Posts
Default

Originally Posted by Eightpter View Post
Check the filter in vst and see if any junk in there. Also check fuel/air psi on rails and see what those are.
Tons of good info in this thread. But, first things first. See bold print above.
Old 05-18-2021, 09:58 PM
  #15  
Junior Member
 
Join Date: Aug 2020
Posts: 7
Likes: 0
Received 3 Likes on 3 Posts
Default

Hey Brownman,
He's a 19 year old kid, who is asking a question trying to learn. Way to try and help him out.
No need to be a wise ass.
Have you always been such a tool or do you just work hard at it?
Likes:
Old 05-18-2021, 10:02 PM
  #16  
Junior Member
 
Join Date: Aug 2020
Posts: 7
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by DonV View Post
NO doubt!! He should have used StaBil 360 and I'm positive he would have had success!! Or the ever famous Seafoam would have fixed that coil!!
Another real fine gentleman. If you think it's the coil just say so.
It's people like you that prevent a lot of people from asking questions, no need to be a wise ass to the kid.


Likes:
Old 05-18-2021, 10:08 PM
  #17  
Senior Member
 
Join Date: May 2021
Posts: 609
Received 75 Likes on 38 Posts
Default

My vote is for checking voltage as previously mentioned. Then next step air fuel mixture as suggested.

Originally Posted by Fishman39 View Post
Dont premix an opti. Bad things happen.
Are these direct injection? I did not think they were. I used to have a couple Opti's back in the day when they first came out and never realized this. I remember going from the EFI to the opti, me and grandma were pumped about it.

I thought the opti just mixed the fuel and oil together before it got to the piston, I did not think it mixed it in the cylinder head?

Last edited by Flocal; 05-18-2021 at 10:13 PM.
Old 05-18-2021, 10:09 PM
  #18  
Junior Member
 
Join Date: Aug 2020
Posts: 7
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by davidwademarine View Post
Ignition coil.
Thank You David,
It is at a mechanics now but even he is having trouble finding exactly what the problem is, I will ask him to check the coil.

He seems to think that there is an leak in the intake valve? Does that make any sense to you?,
He hooked it up to his computer, but he said because it doesn't have the smartcraft it's not giving him any codes.
Thanks for you help.
Old 05-18-2021, 10:14 PM
  #19  
Junior Member
 
Join Date: Aug 2020
Posts: 7
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by Ifishalot View Post
Tons of good info in this thread. But, first things first. See bold print above.
Thank you, I will make sure the mechanic checks fuel and air psi
Old 05-18-2021, 10:25 PM
  #20  
Junior Member
 
Join Date: Aug 2020
Posts: 7
Likes: 0
Received 3 Likes on 3 Posts
Default

Thank you everyone for your suggestions.
Most of them we have tried, ran it on a separate tank, changed all oil and gas filters, checked the battery voltage.
Will be getting new fuel lines and a racor filter set up also.

Again thank you for your advise.

I will let you know what happens,

Brownman and DonV if you'd like I'll come over and personally let you guys know how he made out. Just tell me where you are. It's idiots like you that prevent people from asking questions and learning.
Now get back down in mommies basement where I'm sure your living.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.