1995 70HP Force, cranks but wont fire.

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
Long story short, bought boat 2 months ago after sitting for 2 years. Took out a couple times , did pretty good. Found I was having to choke it after running for a while, it appeared to get hot and cool off and restart way later, then one day it just cut off going down lake at mid throttle, waited a while(hour), started , wouldn't go very fast, died. Got towed back to dock. Changed all 3 coil paks and plug wires..cranks like crazy but won't fire. Definitely flooding....please please somebody...it seemed to be doing so good ...and quiet...thank you.
 

roscoe

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Joined
Oct 30, 2002
Messages
21,758
Classic symptom of torn/perforated fuel pump diaphram.
Fuel leaks through the pump into the crankcase and floods engine.

So, confirm strong spark, then rebuild fuel pump. Its due to be done on a 27 year old engine.

Kit is under $30 from a Mercury dealer and only takes about 20 minutes to replace gaskets and diaphram.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,087
Compression, spark, fuel.
Roscoe says check the fuel pump diaphragm, along those lines, check the primer for a bad diaphragm (pinch off the hose from the primer to the carb).
 

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
Classic symptom of torn/perforated fuel pump diaphram.
Fuel leaks through the pump into the crankcase and floods engine.

So, confirm strong spark, then rebuild fuel pump. Its due to be done on a 27 year old engine.

Kit is under $30 from a Mercury dealer and only takes about 20 minutes to replace gaskets and diaphram.
Thank you, I'll do it!!!!
 

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
Compression, spark, fuel.
Roscoe says check the fuel pump diaphragm, along those lines, check the primer for a bad diaphragm (pinch off the hose from the primer to the carb).
Ok, will check it all. I just didn't know what to even check with out replacing unnecessary stuff.
Ya know what BOAT stands for?
Bust out another thousand!!! I can't do that..thank you.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,518
You must install a new water pump impeller.----Test over heat horn ( if equipped ) on this motor.----Mixing gas and oil at 50:1 in your tank ?----Agreed----Do a compression test.---Post the numbers.
 

Pennylee72

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Joined
Jul 9, 2022
Messages
9
You must install a new water pump impeller.----Test over heat horn ( if equipped ) on this motor.----Mixing gas and oil at 50:1 in your tank ?----Agreed----Do a compression test.---Post the numbers.
Yeah..50:1 on mix.....
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,518
Your motor and some effort has to be put in by you to check a few things.
 

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
Your motor and some effort has to be put in by you to check a few things.
I understand, but I'm no mechanic of any kind, that's why I've posted here. I AM capable of checking and changing things out...just didn't know what to check next.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,087
U-TUBE VIDEO'S
Look on the net for specific tests.
There's a bunch of compression test video's.
The first 4or5 posts in the Force forum has tests and tips for your motor.
I'd stop and go through each one, might be something you need in one of the posts????
If you can't figure it out? then ask for help.
We'll gladly help where we can.

It helps if you fill out the profile and list your location?
You might be close to someone who can help??
 

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
U-TUBE VIDEO'S
Look on the net for specific tests.
There's a bunch of compression test video's.
The first 4or5 posts in the Force forum has tests and tips for your motor.
I'd stop and go through each one, might be something you need in one of the posts????
If you can't figure it out? then ask for help.
We'll gladly help where we can.

It helps if you fill out the profile and list your location?
You might be close to someone who can help??
Ok, thank you. Plan on trying to work on it this weekend. I'm in Hampton, Tn.
 

Pennylee72

Cadet
Joined
Jul 9, 2022
Messages
9
Classic symptom of torn/perforated fuel pump diaphram.
Fuel leaks through the pump into the crankcase and floods engine.

So, confirm strong spark, then rebuild fuel pump. Its due to be done on a 27 year old engine.

Kit is under $30 from a Mercury dealer and only takes about 20 minutes to replace gaskets and diaphram.
There is no fire to plugs or coil paks.. How can I check fire before these? I'm getting it from switch to motor then somewhere in motor to coils there's no fire.?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,518
I believe there is an issue with compression.----Blown head gasket or piston / ring / cylinder problem.----Some will argue.-----I would remove cylinder head first before spending any beer tokens..
 
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