Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > The Boating Forum
Reload this Page >

95 Merc 200hp Blackmax weird fuel issues.

Notices
The Boating Forum

95 Merc 200hp Blackmax weird fuel issues.

Old 09-13-2019, 06:54 PM
  #1  
Member
Thread Starter
 
Join Date: May 2019
Posts: 65
Received 2 Likes on 2 Posts
Default 95 Merc 200hp Blackmax weird fuel issues.

1995 Mercury 200hp 2 stroke Blackmax. I realize now that I am having fuel issues. Very recently I replaced both fuel/water filters. Cleaned out a nasty VST, drained all the gas from plastic tank and inspected what came out. It was all fresh gas with no water and the tank looked clean, pumped all new gas into tank. Also replaced all new fuel lines, inspected the fuel pump and gaskets looked rather new (perhaps previous owner recently rebuilt it). I ran Seafoam thru the motor to clean out injectors. I did not get a chance to test and clean out injectors. But boat fires right up, idles great. First trip after overhaul was 38 miles trouble free with only one hard start. Second recent trip 2 weeks later I went off shore the first 35 miles problem free and boat ran great. THEN 1st stop boat did not fire up as smoothly and took several attempts. But did fire up to move to next tuna spot and shut it down. Repeated 2 more times with similar results where it took a few extra long cranks to fire up. Last time, battery one drained from running electronics. Switch to battery two and that would not start it, some times I would get a click sometimes I get the motor to turn but not fire up. I thought it was a bad battery or drained battery. So I go to 3rd battery which is brand spanking new pull out battery number 2 and hook up new batt and try to fire up motor. Same thing and would not start or just get a click. Finally my friend suggested try starting with applied throttle and it barely fired to life. Left the hot fishing grounds to get back before it gets bad. Well Boat struggled most of the way back with fluctuating throttle. Im confused and would appreciate anyone's help and suggestions on what I can do next to rid this damn gremlin
Old 09-13-2019, 08:04 PM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Jun 2005
Location: Miami, Fl.
Posts: 2,996
Received 1,607 Likes on 765 Posts
Default

It may be time to pull the injectors and send them out to be cleaned professionally. Way better than Seafoam.
Old 09-13-2019, 08:57 PM
  #3  
Member
Thread Starter
 
Join Date: May 2019
Posts: 65
Received 2 Likes on 2 Posts
Default

Originally Posted by SeaCat22 View Post
It may be time to pull the injectors and send them out to be cleaned professionally. Way better than Seafoam.
Yeah, gonna try that but what does a pro do different then pulling each, running pressurized air and cleaner through each? I'll look into it though thanks.
Old 09-14-2019, 06:58 AM
  #4  
Admirals ClubCaptains Club Member Admiral's Club Member
 
Join Date: Dec 2003
Location: Fort Lauderdale, FL
Posts: 6,581
Likes: 0
Received 443 Likes on 262 Posts
Default

If the motor isn’t turning over, you have a bad battery cable or corroded/loose crimp somewhere. I would be checking all battery cable connections very carefully. If they’re more than 10 years old, time to replace with marine grade tinned copper and at least 2 AWG cable size. Be sure to use tinned copper lugs and heat shrink.

Being 95s, those engines have Laser injection which are very sensitive to voltage. You need good power going in at all times. Be sure your batteries have lock nuts on them as well.

Having the injectors cleaned and flowed wouldn’t be a bad idea either way. I think RPM Diesel in Ft. Lauderdale used to charge something like $15 an injector, money well spent for peace of mind and to ensure you don’t lean out a cylinder and blow up the motor.
Old 09-14-2019, 09:27 AM
  #5  
Member
Thread Starter
 
Join Date: May 2019
Posts: 65
Received 2 Likes on 2 Posts
Default

Originally Posted by sundancekid View Post
If the motor isn’t turning over, you have a bad battery cable or corroded/loose crimp somewhere. I would be checking all battery cable connections very carefully. If they’re more than 10 years old, time to replace with marine grade tinned copper and at least 2 AWG cable size. Be sure to use tinned copper lugs and heat shrink.

Being 95s, those engines have Laser injection which are very sensitive to voltage. You need good power going in at all times. Be sure your batteries have lock nuts on them as well.

Having the injectors cleaned and flowed wouldn’t be a bad idea either way. I think RPM Diesel in Ft. Lauderdale used to charge something like $15 an injector, money well spent for peace of mind and to ensure you don’t lean out a cylinder and blow up the motor.
Thanks Kid!! That information is very good to know and will look into that. Typical buying a BOAT. Break Out Another Thousand. Everything I've done to it by myself already is easily over $1k if I was not mechanically inclined and had to take it to a shop. I love this forum!
Old 09-14-2019, 09:31 AM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2018
Posts: 576
Received 872 Likes on 433 Posts
Default

Not sure I would be going 40 miles off-shore and shutting down on a motor with known fuel/start issues... especially with a single. Even with a perfectly running single...
Old 09-14-2019, 10:46 AM
  #7  
Senior Member
 
Join Date: Sep 2012
Location: Bonita Springs, Florida
Posts: 895
Received 589 Likes on 339 Posts
Default

Check your fuel pump relay and wiring to it. Its a long shot, but Symptoms fit. If the Fuel injectors were bad you would loose high ind power. This sounds like a engine hot issue. You should also ohm out your ignition wire to the ignition, ecu and fuel pump. I chased an issue for a year and it was one of the connectors. I was only getting 5 volts to my fuel pump relay when it was hot and it wouldn't fire, Cold I had about 8 even with 14.4 which was just enough to close the contacts. Replaced the connection and boom, battery voltage at relay in all conditions.

Long shot but worth looking at.
Likes:
Old 09-14-2019, 01:41 PM
  #8  
Member
Thread Starter
 
Join Date: May 2019
Posts: 65
Received 2 Likes on 2 Posts
Default

Originally Posted by EMC Pursuit View Post
Check your fuel pump relay and wiring to it. Its a long shot, but Symptoms fit. If the Fuel injectors were bad you would loose high ind power. This sounds like a engine hot issue. You should also ohm out your ignition wire to the ignition, ecu and fuel pump. I chased an issue for a year and it was one of the connectors. I was only getting 5 volts to my fuel pump relay when it was hot and it wouldn't fire, Cold I had about 8 even with 14.4 which was just enough to close the contacts. Replaced the connection and boom, battery voltage at relay in all conditions.

Long shot but worth looking at.
Thanks another good tip! Gonna try this and everything else. I have time as pretty much all the boat shops here in Southern California have a 6 week wait just to bring in the boat.
Old 09-18-2019, 12:58 PM
  #9  
Member
Thread Starter
 
Join Date: May 2019
Posts: 65
Received 2 Likes on 2 Posts
Default

I am hoping I found my issue. While pulling apart fuel system, one of the fuel hoses into the VST was fraying at the clamp. When I was moving around the lines the suspected fuel line sprayed some fuel out under its pressure. Thank the Lord it did not blow up or catch fire while on water, but Im hoping that too much air was mixing with the fuel causing the hard starts. Correct me if I am wrong but the whole fuel system on this motor is slightly pressurized. Im taking apart the fuel rail and get access to each fuel injector so I can pressure clean them individually. The fuel/water filters show zero water and debris. Also all batteries even after trip and sitting for a week were showing between 12.6 and 12.7 volts.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

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

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.