1992 Force 70HP wont start

brianq

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brianq

Petty Officer 2nd Class
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145
My 1992 Force 70 HP Wont start. It was seized up I got it free and now it wont start. I changed the spark plugs, their wires, cleaned the carb. Any suggestions? Here are two videos of what its doing, its different each time. It knocks and shakes and their is exhaust, it sounds like its about to start but just doesnt. Thanks in advanced.

https://www.youtube.com/watch?v=lk5c...ature=youtu.be


https://www.youtube.com/watch?v=gnsy...ature=youtu.be



Additional info: We sparked one of the plugs against the motor and my neighbor believed there wasnt enough spark. I dont have any experience to gauge, there was a small blue spark slightly larger then static not like jumping the solenoid by any means.
 

Jiggz

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It sounds like it is out of fuel. Ensure the air fuel mixture screw (brass screw with spring) is properly set. 1-1 1/4 tuns out from lightly seated. Check the carb bowl make sure it is at least half full after you prime it. I understand this is hard but not impossible by catching all the fuel dripping from the bowl when you unscrew the center screw. Remove the bowl, cover the hole with your finger and replace all the fuel you caught and it should at least cover half of the fuel bowl. This will tell you the inlet needle valve is not stuck shut.

After all of the above, install a clear fuel filter between the fuel pump and the carb inlet. A Fram G2 for less than $5 will do. This is more for troubleshooting than filtering. And it should be left in place even after all problems have been fixed (for future fuel relating troubleshooting it is indispensable). Next get small (pint or quart size) spray bottle and fill it halfway with fuel oil mixture.

Now try starting it again. If it still won't start with the clear fuel filter at least half full, spray fuel oil mix directly into the carb while another person is cranking it. Did it try to start? If it did, check the fuel enricher (choke system) to make sure it is working properly. Remember, to choke or activate the enricher you have to push in the ignition switch while starting.
 

jerryjerry05

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Check the flywheel key. Re-torque to 85#
​Do a compression test. Post the readings.
At almost every auto parts store; an adjustable spark checker get one Under $7
Set it at 7/16in. see if the spark jumps that..
If the comp is good and the key is good and you have spark.
Then the only thing left is the fuel system.
Is there fuel coming from the front of the carb?
The hose from the primer pinch it off and see if that helps.
 

brianq

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Ok thanks for the feed back.

Today I tested compression

Cylinder 1 : 90psi
Cylinder 2: 40 psi
Spark test passed well at 7/16".

The bowl was about 1/2 full of fuel.

I opened the cylinder case once I saw that #2 was so low. I found the head gasket at that cylinder is damaged (photo attached). The first 1/2" of the cylinder wall is pitted and rough. The other 2 were a little rough but with a rag and penetrating oil it mostly came off. Can i sand this his off with some very fine wet sandpaper? I have attached a video of the inside of the cylinders. Please let me know what you guys think. Could the head gasket being damaged be the culprit?

https://www.youtube.com/watch?v=afo4...ature=youtu.be





Cylinder 3: 90 psi





IMG_3990.JPG
IMG_3990.JPG
 
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brianq

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Not sure why it posted so many times now i cant delete.
 

Jiggz

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It doesn't look like there is a damage on the cylinders. I guess the main problem is with the head gasket. Replace it and then do a compression test again. Fine sandpaper is acceptable but steel wool is probably better to clean the mating surfaces on the head.
 

brianq

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It doesn't look like there is a damage on the cylinders. I guess the main problem is with the head gasket. Replace it and then do a compression test again. Fine sandpaper is acceptable but steel wool is probably better to clean the mating surfaces on the head.
Thank you! I will post my results Thursday when the gasket comes.
 

jerryjerry05

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You removing all the plugs when doing comp test?
​The 90# is low.
After the new gasket is installed do another test and see??
If they all stay at 90 maybe get another gauge.
The important thing is all 3 are real close.
 

brianq

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You removing all the plugs when doing comp test?
​The 90# is low.
After the new gasket is installed do another test and see??
If they all stay at 90 maybe get another gauge.
The important thing is all 3 are real close.

I did remove all of the plugs. I will retest tomorrow night, the new gasket comes tomorrow. Its possible the gauge sucks, it is from harbor freight. I did not understand when you said "Check the flywheel key. Re-torque to 85# " what does that mean, sorry im new to all of this.


New Question:
I bought a rocker panel to control my lights and such. It has a voltage gauge and back lighting. If i want it to only come on when the ignition is flipped do I connect it to the solenode as opposed to the battery?

Thanks again
 
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brianq

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I did remove all of the plugs. I will retest tomorrow night, the new gasket comes tomorrow. Its possible the gauge sucks, it is from harbor freight. I did not understand when you said "Check the flywheel key. Re-torque to 85# " what does that mean, sorry im new to all of this.


New Question:
I bought a rocker panel to control my lights and such. It has a voltage gauge and back lighting. If i want it to only come on when the ignition is flipped do I connect it to the solenode as opposed to the battery?

Thanks again


Also does anyone know how much torque to put on the bolts after I install the head gasket?
 

Jiggz

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The head bolts torque value is 225 in-lbs. Let me make sure you got it right INCH-POUNDS! Which is about 18.75 FT-lbs. Make sure you follow the correct torque pattern and do at least a 2 step torque process. Torque step means you do not apply full torque on each bolt initially. Instead with a two step you can apply say, 10 ft-lbs on all bolts and then come back around to do the final torque values.

As for the voltmeter, connect the light wire to the panel switch and the power wire from the ignition switch's. Or if you do not have a panel light switch connect both to the ignition switch.
 

brianq

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The head bolts torque value is 225 in-lbs. Let me make sure you got it right INCH-POUNDS! Which is about 18.75 FT-lbs. Make sure you follow the correct torque pattern and do at least a 2 step torque process. Torque step means you do not apply full torque on each bolt initially. Instead with a two step you can apply say, 10 ft-lbs on all bolts and then come back around to do the final torque values.

As for the voltmeter, connect the light wire to the panel switch and the power wire from the ignition switch's. Or if you do not have a panel light switch connect both to the ignition switch.


When you say the ignition switch do you mean in my shifter where the key goes or back on the motor where all the wires match up by color?
 

Jiggz

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The switch by your shifter. The reason for this is to make sure you do not drain your battery by ensuring the voltmeter and its light only come on when when you turn the switch on. Turning the ignition switch to on does two things, it disconnects the shut down wire from ground and connects power to auxilliaries.
 

brianq

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The switch by your shifter. The reason for this is to make sure you do not drain your battery by ensuring the voltmeter and its light only come on when when you turn the switch on. Turning the ignition switch to on does two things, it disconnects the shut down wire from ground and connects power to auxilliaries.



Ok so in there will be an auxillary hot? Then do all the grounds go to a ground bar which then gets grounded to the neutral on the battery? Sorry for the basic questions I usually work on houses.
 

Jiggz

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That is correct. The negative wire goes to the ground bar where the rest of them are connected. If you look at the terminal on the ignition switch one terminal is designated, "I" which is basically nothing but auxilliaries connection. The terminal maybe crowded unless there is also an auxilliaries bar where all meters, radio, lights, etc are also connected.
 

brianq

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Joined
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Messages
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That is correct. The negative wire goes to the ground bar where the rest of them are connected. If you look at the terminal on the ignition switch one terminal is designated, "I" which is basically nothing but auxilliaries connection. The terminal maybe crowded unless there is also an auxilliaries bar where all meters, radio, lights, etc are also connected.



Well gents I have some devastating news ... I installed the new head gasket tonight and the compression readings were: 90, 60, 90. All my neighbors agree its time for a new motor or power head. What are your thoughts?
 
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