Logo
FULL SITE MENU

9.9 1974 Johnson Heavy Black On Plug

I would think you would remember that one. The reason it is so memorable is the difficulty of getting the older one out. The piece I am talking about is called the slow speed needle bearing. It's plastic and looks like a very miniature funnel.
 
I can't help believing that your problem is totally related to fuel delivery. Your compression is good and you seem to have awesome spark, on both cylinders, properly timed with your 0.020" point gap. Since I don't think you can manually clean a fouled plug when you say you clean them up and they work again, I can't help thinking that they were never fouled in the first place. You have also changed them enough times to probably rule out spark plug fouling.

If this was my motor this is what I would do. You must get that fuel pump to pass the blow test. That means taking it apart again or buying another one. Once the fuel pump passes the blow test I would do the following. Attach the incoming fuel hose to the fuel pump but keep the pump away from the engine. Squeeze the primer bulb and observe if gas flows out the output side of the fuel pump and if any gas leaks out the pulse port or anywhere else on the fuel pump. The answer to those observations must be yes and no. Then I would attach the pump to the motor but not the carb and I would pull on the starter rope to verify that fuel pulses out the output of the fuel pump. If it does not, then your problem is a continual problem with the fuel pump or a problem with the fuel hose, the connectors, the fuel tank or an air leak. If fuel does pulse out of the fuel pumps output then your problem must be with the carburetor.

Those are my thoughts at this point in the investigation.
 
optsyeagle said:
I would think you would remember that one. The reason it is so memorable is the difficulty of getting the older one out. The piece I am talking about is called the slow speed needle bearing. It's plastic and looks like a very miniature funnel.
Click to expand...
Was not memorable and I just watched a few you tubes and they skipped talking about this part and did not install it. Did the original come out or was there even an original? Best guess is the one I had was installed. The needle went back to its original position and fired up right away. I will keep an eye on this if I remove the needle after we get this running.
 
optsyeagle said:
I can't help believing that your problem is totally related to fuel delivery. Your compression is good and you seem to have awesome spark, on both cylinders, properly timed with your 0.020" point gap. Since I don't think you can manually clean a fouled plug when you say you clean them up and they work again, I can't help thinking that they were never fouled in the first place. You have also changed them enough times to probably rule out spark plug fouling.

If this was my motor this is what I would do. You must get that fuel pump to pass the blow test. That means taking it apart again or buying another one. Once the fuel pump passes the blow test I would do the following. Attach the incoming fuel hose to the fuel pump but keep the pump away from the engine. Squeeze the primer bulb and observe if gas flows out the output side of the fuel pump and if any gas leaks out the pulse port or anywhere else on the fuel pump. The answer to those observations must be yes and no. Then I would attach the pump to the motor but not the carb and I would pull on the starter rope to verify that fuel pulses out the output of the fuel pump. If it does not, then your problem is a continual problem with the fuel pump or a problem with the fuel hose, the connectors, the fuel tank or an air leak. If fuel does pulse out of the fuel pumps output then your problem must be with the carburetor.

Those are my thoughts at this point in the investigation.
Click to expand...
100% behind your thoughts. Just told the wife I am going to work! Lol
 
Here the exact way I had assembled it. Small spring was on the right hand side of block.
The base has no parts that can fail? Air freely blows through.
 
optsyeagle said:
I can't help believing that your problem is totally related to fuel delivery. Your compression is good and you seem to have awesome spark, on both cylinders, properly timed with your 0.020" point gap. Since I don't think you can manually clean a fouled plug when you say you clean them up and they work again, I can't help thinking that they were never fouled in the first place. You have also changed them enough times to probably rule out spark plug fouling.

If this was my motor this is what I would do. You must get that fuel pump to pass the blow test. That means taking it apart again or buying another one. Once the fuel pump passes the blow test I would do the following. Attach the incoming fuel hose to the fuel pump but keep the pump away from the engine. Squeeze the primer bulb and observe if gas flows out the output side of the fuel pump and if any gas leaks out the pulse port or anywhere else on the fuel pump. The answer to those observations must be yes and no. Then I would attach the pump to the motor but not the carb and I would pull on the starter rope to verify that fuel pulses out the output of the fuel pump. If it does not, then your problem is a continual problem with the fuel pump or a problem with the fuel hose, the connectors, the fuel tank or an air leak. If fuel does pulse out of the fuel pumps output then your problem must be with the carburetor.

Those are my thoughts at this point in the investigation.
Click to expand...
Could not get this pump assembly to pass the blow test. Tried a ton of times and went over all instructions and some videos to problem solve what I could be doing wrong. I could not find anything.
I think part # 329974 could be defective. Any way to test this component?

I may end up buying the assembly since this part does not come in a kit.
 

Attachments

  • IMG_0600.jpeg
    IMG_0600.jpeg
    670.1 KB · Views: 7
I am not familiar with the insides of the fuel pump to say one way or the other but this guy on ebay is selling one and his picture does not have the metal piece you do in the bottom right hole or maybe I am just seeing the other side of what you are showing.

www.ebay.com

OEM JOHNSON EVINRUDE OMC 329974 OUTBOARD MOTOR SMALL FUEL PUMP HOUSING 0329974 | eBay

If possible, take pictures and send them to us - and we will assist you in replacing your order.
www.ebay.com
 
optsyeagle said:
I am not familiar with the insides of the fuel pump to say one way or the other but this guy on ebay is selling one and his picture does not have the metal piece you do in the bottom right hole or maybe I am just seeing the other side of what you are showing.

www.ebay.com

OEM JOHNSON EVINRUDE OMC 329974 OUTBOARD MOTOR SMALL FUEL PUMP HOUSING 0329974 | eBay

If possible, take pictures and send them to us - and we will assist you in replacing your order.
www.ebay.com
Click to expand...
Yeah I saw that. Both sides have the metal part 180 degrees apart so his won’t help me.
 
Post 100 as predicted.-------The pocket in the middle is the seat for the spring.-----The spring goes there with the disc touching the diaphragm.-----Nothing between the diaphragm and the base of the pump.
 
racerone said:
Post 100 as predicted.-------The pocket in the middle is the seat for the spring.-----The spring goes there with the disc touching the diaphragm.-----Nothing between the diaphragm and the base of the pump.
Click to expand...
We will be at 150 soon enough.
What does that middle section do besides act as a pocket for the bottom spring?
 
It is where the spring sits.----It holds the spring in place.----It has the check valves that allow fuel in and allow fuel out.-----These pumps are elegantly simple.----The pump is powered by crankcase PRESSURE pushing on the diaphragm.-----Compresses the spring.----Then when piston goes up into the cylinder the spring pushes the diaphragm back.---That action pulls fuel from the tank.
 
racerone said:
It is where the spring sits.----It holds the spring in place.----It has the check valves that allow fuel in and allow fuel out.-----These pumps are elegantly simple.----The pump is powered by crankcase PRESSURE pushing on the diaphragm.-----Compresses the spring.----Then when piston goes up into the cylinder the spring pushes the diaphragm back.---That action pulls fuel from the tank.
Click to expand...
So the check valves on this block should be activated by my breath much like the final assembled test?
Based on my pump fuel will come into the chamber in green and through the valve and then return through metal side(red) and out to carb? There is a passageway connecting to chamber on right
The small spring will be the right hand chamber connected to the tube for carb.
 

Attachments

  • IMG_0602.jpeg
    IMG_0602.jpeg
    404.3 KB · Views: 5
Not sure if you saw this video but this guy tries to explain the variation of where the spring goes with respect to the output of the pump (the red I assume in your picture). I think that part is around 8 minutes into the video for a couple minutes after that.

 
optsyeagle said:
Not sure if you saw this video but this guy tries to explain the variation of where the spring goes with respect to the output of the pump (the red I assume in your picture). I think that part is around 8 minutes into the video for a couple minutes after that.

Click to expand...
Thanks. I did see this video and a few others lol!
All lines up with what I am doing…..except for the blow test.
New pump on order and we can talk in a few days.
 
A new pump should solve the fuel pump problem.

The only other piece of useful info that I saw on a video was about that little flap on the part you posted in post #97. It should have an arrow on it or the words UP, not sure. That is to ensure that it is up when it is attached to your motor for proper operation.
 
optsyeagle said:
A new pump should solve the fuel pump problem.

The only other piece of useful info that I saw on a video was about that little flap on the part you posted in post #97. It should have an arrow on it or the words UP, not sure. That is to ensure that it is up when it is attached to your motor for proper operation.
Click to expand...
Yeah. The part in pic is upside down to how it is assembled. I wanted the tab with part # in the pic.
 
I would probably also do the 3 tests I mentioned on the new fuel pump as well. They are:

1) blow test
2) Connect input hose only and then squeeze primer bulb and watch fuel flow out output and check for leaks.
3) Attach fuel pump to motor and pull starter rope and watch pump output for pulsing fuel.

Although a new pump should ensure all those wonderful things happen, if you install it and your motor still has a problem the very first thing you are going to ask yourself is if the new fuel pump worked right. Might as well ensure it does before you do the operational test of the motor on the boat.
 
optsyeagle said:
I would probably also do the 3 tests I mentioned on the new fuel pump as well. They are:

1) blow test
2) Connect input hose only and then squeeze primer bulb and watch fuel flow out output and check for leaks.
3) Attach fuel pump to motor and pull starter rope and watch pump output for pulsing fuel.

Although a new pump should ensure all those wonderful things happen, if you install it and your motor still has a problem the very first thing you are going to ask yourself is if the new fuel pump worked right. Might as well ensure it does before you do the operational test of the motor on the boat.
Click to expand...
Ok new pump arrived late yesterday and passed blow test and testing on the motor. Looked like good flow.
Did not start. Primed and choked but no luck no ignition.
Checked pump a few times and all seemed fine.
Checked spark and looks very strong on both.
Checked compression again and still good with both around 120 psi.
Idle needle was set at 1 1/2 turns out and adjusted this. Both out and in with no change.
Can see fuel at mouth of carb.
Removed carb.
Removed idle screw as well as Welsh plug on top just to make sure. Seemed to be some debris but sprayed it and blew it out. Put back in and backed it out 11/2 turns.
Sprayed and blew out high speed jet as well.
Assembled and reinstalled with no improvement.
Engine does not even think of starting.

Open to any ideas on where we go next.

Thanks for reading!
 
Are you getting any reaction from the motor when trying to start it?

Put some pre-mix fuel directly into the cylinders and give it a start and let us know the reaction of the motor, if any.
 
optsyeagle said:
Are you getting any reaction from the motor when trying to start it?

Put some pre-mix fuel directly into the cylinders and give it a start and let us know the reaction of the motor, if any.
Click to expand...
Ok so checked fuel pump again and it seems fine pumps with with primer and with drill on flywheel
Checked for spark and both seem strong. This was with the drill on flywheel
Sprayed starter fluid into carb(do not have a spray that would get my gas mix into it) using the drill the motor made no attempt to start
Sprayed starting fluid into each cylinder and and using the drill the motor did not start or think of starting.
I am using the drill only because the motor is making no attempt to start. Once I here it try I will go back to pulling it.
 
Well you seem to have the fuel pumping problem resolved. If fuel directly into the cylinders does not give any attempt to start then it must be spark or compression. Your compression numbers are good and you have tested for spark and found you have it. The only other thing it could be is either spark timing or the spark plugs themselves. Try some brand new spark plugs in there and if that does not fix it then it is time to pop the flywheel and check the flywheel key and point gaps.
 
optsyeagle said:
Well you seem to have the fuel pumping problem resolved. If fuel directly into the cylinders does not give any attempt to start then it must be spark or compression. Your compression numbers are good and you have tested for spark and found you have it. The only other thing it could be is either spark timing or the spark plugs themselves. Try some brand new spark plugs in there and if that does not fix it then it is time to pop the flywheel and check the flywheel key and point gaps.
Click to expand...
Went out and got the plugs B7HS and what do you know. The beast fires up on second pull.
Pump seems to be working fine and the motor seems to be running ok in the barrel. I had the idle at 11/2 turns out but ending up adjusting this to 11/8 turns out. Seems to idle ok and ran in gear it at 1/3 throttle for 20 min or so. There was some smoke but it seemed to reduce over time.
I was able to rev it up higher for short bursts with no negatives except for small increase in smoke.

So it might be time for a road test! I will take it out on the water tomorrow and see how it goes at full throttle.

Thanks optsyeagle!
 
patiolatern said:
Went out and got the plugs B7HS and what do you know. The beast fires up on second pull.
Pump seems to be working fine and the motor seems to be running ok in the barrel. I had the idle at 11/2 turns out but ending up adjusting this to 11/8 turns out. Seems to idle ok and ran in gear it at 1/3 throttle for 20 min or so. There was some smoke but it seemed to reduce over time.
I was able to rev it up higher for short bursts with no negatives except for small increase in smoke.

So it might be time for a road test! I will take it out on the water tomorrow and see how it goes at full throttle.

Thanks optsyeagle!
Click to expand...
Post 117!!!!
Well the boat test went better than hoped! Warmed it up at the dock then put it in gear and all went well. Ran at 1/2 throttle for 15 min the full throttle for another 15 -20 min. Took a look at plugs and they looked pretty normal.
Started well each time.
Thanks optsyeagle!!! Your help and patience was very much appreciated!!!!!
 
Back
Top