78 Stinger75 starts and runs fine on land

[biggizmo]

Have a question...when I went through the link and synch procedure. I dropped a washer down inside the motor housing pit..so I got an extractor tool out and found several screws and a black rubber stop bumper. It looks like one that SHOULD have been on the spark advance stop screw. If it isn't there...is it POSSIBLE that it may be advancing too far during my throttle advancing while driving my boat. And that is what is causing the choking and dying problem? Wife wants to sell boat if I can't figure this out. We are taking it out for one more try. Please help.

 

[biggizmo]

Does anyone know how to solve my problem with this motor?

 

[racerone]

There may be issues with your motor that can not be solved by the famous ---link & synch ----procedure.----What other trouble shooting have you done ?----What trouble shooting are you prepared to do ?---Yes that missing rubber stopper may advance the timing too far.---But I doubt that is the issue here.

 

[jimmbo]

Did you check the max advance timing? Sometimes a misadjusted Sync can cause bogging and stalling, but as racer said the problem may be elsewhere. Start with a compression test, spark test, meaning can it jump a 3/8" gap, then the carbs. Fuel level and dirt/gum/varnish come to mind

Other basics, spark plugs and wires

 

[biggizmo]

Okay...Thank you for responding.
As I mentioned before...I have 120 to 128 psi per cylinder.
Seafoam treatments. Cleaned carbs. Good fuel llevels. Great spark...even got a wonderful awakening zap when I was pulling each plug wire while RUNNING. The meters and other fancy tools for setting rpms and idle synching are not available here in this small community. I talked with the mechanics at our local marine shop and they can run some tests for about $200. They will then fix or adjust for another $289.
I haven't fallen off no turnip truck and believe that is a bit high for an analysis and adjustment.
I don't have a Johnson/Evinrude Bible and the pdf's I found online won't open. ($60 waste )
I am not puking fuel but consumption is high.
Doesn't smell rich and doesn't backfire or any of that.
Just can't get it to power up on the water.
No throttle...just a hesitant idle at half throttle.
This is something simple but I am stumped.
Thanx for any imput.

 

[biggizmo]

And...yes...willing to go as far as it takes to get this on the water. The engine is emaculately clean inside and out.
I also spoke with an old timer here and he mentioned something about a vacuum leak at carb base. Thinks I am sucking water into the intake. Is this possible?

 

[flyingscott]

What is your motor actually doing specifically? There are no special tools for the link and sync. And no you are not sucking water into the intake.

 

[racerone]

Bring it over ---I think I can figure it out for less than 1/2 what this shop wants !!

 

[biggizmo]

What is your motor actually doing specifically? There are no special tools for the link and sync. And no you are not sucking water into the intake.

Runs great on land in tank and with muffs.
Put it in water and acts like it had never been started.
Finally it starts andvwarms up on idle.
Put it in gear it moves away from dock.
Engage throttle up and it only gets about half way before it will hesitate then throttle slightly to a 3 MPH cruise.
Throttle further and it does.
Try to start and it won't start for several minutes.

 

[biggizmo]

Bring it over ---I think I can figure it out for less than 1/2 what this shop wants !!

I am in Moses Lake, Washington.
Where are you located...?

 

[biggizmo]

Canada it QUITE a journey from my location.
I could buy a new motor for the cost of driving my truck that far.

 

[racerone]

There must be a shop in your area that caters to older motors and common working folks.----Look around and make some calls.-----First thing I would look at is the starter motor.----Take it apart for inspection / ohm test.-----Then look at diaphragm in fuel pump , $6.00 to replace that item.

 

[biggizmo]

There must be a shop in your area that caters to older motors and common working folks.----Look around and make some calls.-----First thing I would look at is the starter motor.----Take it apart for inspection / ohm test.-----Then look at diaphragm in fuel pump , $6.00 to replace that item.

Nothing wrong with starter motor...cranks right up and starts with the flick of the key.
Now...here is what I found...
My fuel delivery fixture on the tank...(plastic) has a 360° outlet. The brass fitting on the outlet is fine...but I fount two cracks on the threaded elbow the receives the hose and bulb. Also...the main hex fixture that screws into the tank has splits on both sides running through the threads. That is normal as it is a three piece unit. However, the seam appears to be OVER EXAGERATED. When I squeeze the bulb I get some fuel bleeding at the crack seams. That is not normal and tells me I am trying to pump air into my fuel pump. So...I removed the unit and ran the hose directly from the bottom of tank. Got full throttle and great idle.
Now...the test. Tomorrow I take it out and run the engine in the lake with just the hose stuck into the tank. Wish me luck.

 

[jimmbo]

. So...I removed the unit and ran the hose directly from the bottom of tank. Got full throttle and great idle.
Now...the test. Tomorrow I take it out and run the engine in the lake with just the hose stuck into the tank. Wish me luck.

Full Throttle, but not at the lake? Where? Keep doing that and you won't have to worry about fuel issues

 

[biggizmo]

What would you think about this being the problem?
The crack on the plastic housing for fuel delivery runs full length of brass fitting.
This is off a Tempo 6.5 gal tank.
Could I just be pumping air which makes for over compensation on spark advance?
1.5 to 2.5 psi at fuel delivery between idle to open throttle is spec. But am I losing fuel delivery with this crack?
We are taking boat out to run the line direct from tank to fuel pump without the cracked piece.
If it runs better and I can throttle past trolling speed I could accept the cause and replace the part...it is on order from iBoats through Amazon. About $8.00 and was only one left.

 

[flyingscott]

somebody over tightend the fitting and cracked it.