88 sea ray with 3.0 mercruiser.

Wfritts

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Aug 10, 2021
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Boat is hard to start. I have replaced plugs,wires,distributor points,condenser and ignition coil. Still had no spark. Wiggled some wires and finally got it to start. Runs rough at low to mid idle but at full throttle runs great. Notice black like substance on the water being discharged from exhaust. No rainbow color. Is this running to rich at low to mid idle or are the rings going bad. Also what should the psi be if running compression test? Thanks for your help in advance.
 

Rick Stephens

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Aug 13, 2013
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Fairly simple progression of testing and adjustments needs to be done. First thing is to do a compression test and see what the baseline condition of the motor is. Next thing is to go through all the connections and take them apart, brush them clean and get them back tight again. Everything you said points to corroded connection being part of your problem.
 

Wfritts

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Aug 10, 2021
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9
Fairly simple progression of testing and adjustments needs to be done. First thing is to do a compression test and see what the baseline condition of the motor is. Next thing is to go through all the connections and take them apart, brush them clean and get them back tight again. Everything you said points to corroded connection being part of your problem.
When running compression test what is the psi range each cylinder should be?
 

Wfritts

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Aug 10, 2021
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New motor will be 150. Need an accurate gauge for that precision. More important is differences between cylinders.

Decent guide here.
Starting in the front working towards the Aft. 1=140 , 2=135, 3=135 and 4=130. I finally got it to start and run but something is up with the electronic choke. When it is hot the choke is on flap closed and engine is hot. Sometimes flap will stay opening but then when putting it in gear the flap will close and engine will die. I have tried adjusting the choke but get same result. I will buy a meter today to see if I get juice to the electronic choke. Should I see 12v at wire that plugs into choke? Thanks for your time and knowledge
 

kenny nunez

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Jun 20, 2017
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Depending on what part of the country may also help. I generally adjust the choke where the butterfly is just barely closed. Since the choke is electric it is normal for it to close on a warm engine when the engine is not running.
And of course there has to be 12 volts when the engine is running.
 

Rick Stephens

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Your compression is fine. Agree with Kenny on choke settings. Adjust cold where the butterfly is almost closed - I am at altitude and don't need full choke. So I leave it open 3/16" or so when fully activated. The 12V to the choke is the same source 12V as the coil gets. Purple wire.
 

Wfritts

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Aug 10, 2021
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9
Depending on what part of the country may also help. I generally adjust the choke where the butterfly is just barely closed. Since the choke is electric it is normal for it to close on a warm engine when the engine is not running.
And of course there has to be 12 volts when the engine is running.
Thanks and I will adjust again
 

Wfritts

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Aug 10, 2021
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Your compression is fine. Agree with Kenny on choke settings. Adjust cold where the butterfly is almost closed - I am at altitude and don't need full choke. So I leave it open 3/16" or so when fully activated. The 12V to the choke is the same source 12V as the coil gets. Purple wire.
Thanks again
 

Wfritts

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Aug 10, 2021
Messages
9
New motor will be 150. Need an accurate gauge for that precision. More important is differences between cylinders.

Decent guide here.
Is it possible that the electric choke part is bad. I have 12.88v at connections but choke spring does not heat up. Where can I find one? Sea Ray of Cincinnati told me you had to buy new carb to get new electric choke. Thanks
 

kenny nunez

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Jun 20, 2017
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3,327
Contact flyingfishcarburetors. They specialize in rebuilding marine carburetors. They should have what you need.
 

Harritwo

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Oct 4, 2011
Messages
586
I had the 3.0 and anytime it was hot it was difficult to start. Finally turned choke off, and no issues cold or hot. When hot engine, open throttle 1/4 and see if it starts easier when you get choke adjusted. In Texas and Florida, I don’t need a choke so had mine turned off
 

Scott06

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Apr 20, 2014
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6,725
Is it possible that the electric choke part is bad. I have 12.88v at connections but choke spring does not heat up. Where can I find one? Sea Ray of Cincinnati told me you had to buy new carb to get new electric choke. Thanks
Mikes carb parts sells the choke coil
 

Wfritts

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Aug 10, 2021
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9
Thanks for your help. Part is on oder and will let you know if this solved my issues.
Okay so I replaced electric choke. When I turn key to the on postion and wait 2 minutes I can feel the electronic choke housing warm up but choke does not open. Is it possible that carb needs rebuilt? I started it up and runs fine but when I put it in neutral it dies now. I have ordered a rebuild kit for carb. I am very frustrated with it. Any ideas?
 

Scott06

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Apr 20, 2014
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Okay so I replaced electric choke. When I turn key to the on postion and wait 2 minutes I can feel the electronic choke housing warm up but choke does not open. Is it possible that carb needs rebuilt? I started it up and runs fine but when I put it in neutral it dies now. I have ordered a rebuild kit for carb. I am very frustrated with it. Any ideas?
Where in terms of rich/ lean did you set the choke element? After two minutes i wouldn’t expect it to be open much.loosen the screws, start engine , Turn the choke element so when engine is warm it is fully open. Verify linkage is clean and not hanging up.
carb may need rebuilding but start with basics set ignition timing, set carb mix and idle speed. If you choke has been hanging up closed may want to clean or replace spark plugs if they are black and fouled.
 

Wfritts

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Joined
Aug 10, 2021
Messages
9
Where in terms of rich/ lean did you set the choke element? After two minutes i wouldn’t expect it to be open much.loosen the screws, start engine , Turn the choke element so when engine is warm it is fully open. Verify linkage is clean and not hanging up.
carb may need rebuilding but start with basics set ignition timing, set carb mix and idle speed. If you choke has been hanging up closed may want to clean or replace spark plugs if they are black and fouled.
I set the choke when engine was cold so that flap was barely closed. I did notice that choke is hanging up a little bit. I still do not understand why engine would die when putting it in the neutral position. Rebuild kit is on its way. Thanks for your support.
 
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