Engine idles and runs fine but bogs down ans will not get on plane

jsearnest

Recruit
Joined
Oct 8, 2003
Messages
3
86-88 150 Mariner Magnum V6 motor<br />engine idles and runs fine but bogs down and will not get on plane
 

greasemonkeyozi

Petty Officer 1st Class
Joined
Jul 16, 2003
Messages
282
Re: Engine idles and runs fine but bogs down ans will not get on plane

Typical fuel problem. Try this roubleshooting guide. (1) Check your spark. Dissconnect one plug wire at a time and hold it close to the motor to ground it out. Have someone attampt to start motor and inspect for an even blue spark on each plug wire.<br /> (2) Check for any possible fuel leak while priming bulb. Check from fuel tank all the way to your carborators. Dont check when motor is running, you will be wasting your time. If there is a leak, your fuel line would be sucking in air. Double check that connector that hooks fuel line to motor, sometimes those things have a rubber O ring that may dryrott. <br />(3) Dissconnect fuel line right at carborators and have someone attempt to start motor. Look and see if fuel pump is pumping fuel good. If you cant tell if fuel pump is not pumping good or not, go to your local dealer and purchase a Fuel Pump Diaphram Kit to rebuild your fuel pump. Thats an easy $5.00 do it yourself job. Remember, the pump works by using the vaccume from your motor, dont let it confuse you.<br /> (4) If all of these guides are not helping out any, you may be havind a problem with your carborators, and may need to rebuild them. There is another possability that you have a piece of trash in a carborator jet. Go to NAPA and purchase you a can of SEA FOAM DEEP CREEP and spray some in your carborators while motors running. Spray in short squirts for about 5-10 minutes to clean your carborators out. Then check your idler screws and make sure they are adjusted correctly. Screw both of them in all the way, do not tighten them, just snug em all the way, then rotate them counterclockwise 2 full rotations. Now your carborators are set. If that doesnt fix your problem, you need to rebuild your carborators. Thats an easy job too, but for now, consintrate on troubleshooting that motor. Let us know how you do.
 

Hasbeen

Petty Officer 2nd Class
Joined
Aug 29, 2003
Messages
167
Re: Engine idles and runs fine but bogs down ans will not get on plane

Give us a little more information to go on!<br /><br />Did this just all of a sudden just happen?<br />Has it been running fine all the rest of the season?<br />Did you just get the boat?<br />Has it been sitting for longer than 2 or 3 months?<br /><br />Lots of help here, someone will be able to help you given enough information!<br /><br />Hasbeen
 

jsearnest

Recruit
Joined
Oct 8, 2003
Messages
3
Re: Engine idles and runs fine but bogs down ans will not get on plane

Did this just all of a sudden just happen? –- Yes, I took off to go fishing at a spot…When I stopped the boat the engine choked a bit…when I was done fishing and I started the boat again…I went to take off and couldn’t get on the plane.<br /><br />Has it been running fine all the rest of the season? –- Happened about June…boat was running fine before that.<br /><br />Did you just get the boat? -- No, I’ve had the boat since 98.<br /><br />Has it been sitting for longer than 2 or 3 months? -- It hadn’t been sitting for more than a few days when it happened, but it’s now been sitting since about July. Finally, found time to work on it.
 

Hasbeen

Petty Officer 2nd Class
Joined
Aug 29, 2003
Messages
167
Re: Engine idles and runs fine but bogs down ans will not get on plane

Im going to guess electrical but am not a outboard specialist! Ironically Im having a similar broblem with my 150 Merc! I think that it is a coil switch on mine! I have one ordered and have not received it yet so really do not know if this is going to fix the problem! This dosnt help you though!<br /><br />Someone else will jump in here eventually and put there 2 cents worth in!<br /><br />Hasbeen
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: Engine idles and runs fine but bogs down ans will not get on plane

You are going to have to check the compression and the spark. Then get back to us.<br /><br />TMD
 

greasemonkeyozi

Petty Officer 1st Class
Joined
Jul 16, 2003
Messages
282
Re: Engine idles and runs fine but bogs down ans will not get on plane

Let me back up, you just said that everything was fine until you cranked up to take off. If it helps,the exact same thing happened to me man, I feel your pain. I still feel like its fuel problem, especially in one of your carborators. Just calm down, and follow the troubleshooting guide I sent be4. Me and the Marine Doctor is here 24-7 and will be glad to help (YOU) fix your motor. Piece of cake, right? ;)
 

jsearnest

Recruit
Joined
Oct 8, 2003
Messages
3
Re: Engine idles and runs fine but bogs down ans will not get on plane

Thank you, thank you, thank you! Mercury Grease Rag...you saved my boats life! By following your step by step troubleshooting guide, I started checking the sparks and realized that 3 cyl. on one side were sparking and only 1 on the other side. I started moving some wires around and got other 2 cyl. to spark and that's when I realized that one of my switch boxes was malfunctioning. Though I did rebuild my fuel pump and my carborator just for good measure. It looks like the switch box should only cost me about $200. More than I'd like to spend, but at least I know I'll be on the water again in the next week or two.<br /><br />This is the first time I've used this website and I gotta tell ya, it has been a wonderful experience. Thank you all so much for sharing your knowledge of boats with me. Hopefully, someday soon, I'll be able to return the favor and help someone else get back on the water too.
 
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