1976 Johnson 9.9 10R76H

rwilso

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Oct 24, 2010
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Motor will run in netural for a short time and then will speed up and die then it is hard to start
:confused:
 

bktheking

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Re: 1976 Johnson 9.9 10R76H

Sounds like the carb is doing it's part. Pump the carb up full, pull the fuel line going to the carb and put in a gas can. Start the motor and see if it's pumping gas.
 

rwilso

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Re: 1976 Johnson 9.9 10R76H

I put a clear line on and it has a lot of air bubles in it. I cleaned the carb but did not install a new kit. I also put in new points, condensers, plugs and plug wires. (Re carb kit I have one now, should I go ahead and install it since I have the Carb off
 

bktheking

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Re: 1976 Johnson 9.9 10R76H

Go ahead and do the kit, sounds like you have a pump issue, a bad fuel line or something.
 

rwilso

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Re: 1976 Johnson 9.9 10R76H

Do you know if a fuel pump from a 1985 J10ElCom 9.9 will work on this motor
 

Will Bark

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Re: 1976 Johnson 9.9 10R76H

Wouldn't air in the fuel line indicate that air is getting in the fuel line from somewhere; loose connection somewhere.:confused:
 

jmendoza

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Jun 9, 2008
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Re: 1976 Johnson 9.9 10R76H

Make sure the fuel lin is not leaking at the connector, and make sure the o rings in the connector on the line from the tank(both ends, both connectors) are good because any leake will make it suck air instead of fuel. Bubbles indicate you have a leak between the tank and pump inlet.
 

rwilso

Seaman
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Oct 24, 2010
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Re: 1976 Johnson 9.9 10R76H

I hooked a clear hose between the bulb and the pump and one from the pump to the carb and used hose clamps to secure the hose at all conntecions. The bubbles are in the outlet side of the pump. My neighbor has a 1985 9.9 fuel pump and I was wondering if it would work on my motor to test the pump I can keep it running if I continue to squeeze the bulb.
 

bktheking

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Re: 1976 Johnson 9.9 10R76H

Should be the same pump, sounds like a bad fuel pump diaphram.
 

rwilso

Seaman
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Oct 24, 2010
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Re: 1976 Johnson 9.9 10R76H

I just finished rebuilding the fuel pump and motor started and ran for about 5 min before it died I am going to install a carb kit tomorrow I hope that helps
 

ONERCBOATER

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Oct 11, 2010
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Re: 1976 Johnson 9.9 10R76H

make sure that the jets are very clean when you rebuild the carb, i have known lots of folks to rebuild carbs and not get everything clean and be miserable. that said, i think you are on the right track, with bk assisting you I know you are getting the right info.

Sean
 

bktheking

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Re: 1976 Johnson 9.9 10R76H

Before you do the carb, does it still have spark???? What about compression, is there a chance it overheated?
 

rwilso

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Oct 24, 2010
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Re: 1976 Johnson 9.9 10R76H

It has good spark (checked with spark tester) and the compression is 95 in both cylinders and it has not over heated to my knowledge. The impeller was changed last fall and water circulates very good.
 

eavega

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1,377
Re: 1976 Johnson 9.9 10R76H

I just finished rebuilding the fuel pump and motor started and ran for about 5 min before it died I am going to install a carb kit tomorrow I hope that helps

Is this about how long it ran before? You may have an ignition issue that will only manifest itself when motor reaches operating temperature. Heat expansion may be causing something to go out of whack and lose spark. Make sure you still have spark when motor quits.

Rgds
 

jrs_diesel

Chief Petty Officer
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Mar 3, 2010
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Re: 1976 Johnson 9.9 10R76H

Sounds to me like fuel delivery.

What I suspect is happening is that the fuel pump is broken. Think about it, the primer bulb is used to first get fuel from the tank to the carb, and goes through the fuel pump. Engine is started, but since the fuel pump is broken no more fuel flows to the carb. The carb bowl gets emptied since no more fuel is flowing to it, and right before the engine dies it speeds up (leans out once the fuel in the bowl is used up). The RPMs going up right before it dies is what tipped me off here.

Since the engine runs (at idle anyway) the carb is at least working, spark should not be an issue. Whenever I have run the gas out of the carbs of my small motors (even my 4 stroke), the engine always revs up a bit before it dies (leans out).
 

rwilso

Seaman
Joined
Oct 24, 2010
Messages
55
Re: 1976 Johnson 9.9 10R76H

New points & condensers - Rebuilt fuel pump - Rebuilt carb & fixed leak at fuel line fitting. Motor starts easy and runs great ( 45 min in tank ) I will put it on a boat next week for for a good test. Oh yes rod and reel will accompany me for this test. Thanks for all the input.:)
 
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