fuel system question

[airwarrior]

73 Johnson 85 hp.

Ok rebuilt carbs, replaced all fuel lines on engine, checked and cleaned fuel filter screen and I am not getting any fuel out of the carbs into the engine. The plugs are bone dry. I had this same problem prior to pulling and rebuilding the carbs.
The carbs have gas (pulled drain screws quite a bit comes out) but I am losing pressure from somewhere. The tank, fitting, hose and bulb are new. The line coming out of the bulb (yes arrow is point the rigth direction) was existing, but I blew air through it and the filter is clean so I think it is debris free. I can pump the bulb up and it gets firm, and stays firm. If I tilt the bulb air the arrow point up I can hear a girgling sound, like it is draining back into the tank. The fitting on the end of the hose that attaches to the engine has some play, you can wiggle it but it doesnt leak fuel.

I am not sure if I am losing pressure, have a defective bulb, bad fitting etc.... Since I am working on this all by myself, it is a reach from the center console to the motor.... I wanted to see if I was getting any fire... I cant see the plugs so I gave a little shot of starting fluid, I mean a very little shot.... I know it isnt good to do that but one time for a test shouldnt hurt... I hit the ingition switch and it sounded like it wanted to start.

So I am wondering what I have going on here.... a leak in the fuel system somewhere and I am losing pressure or a blockage of some kind that lets me pump but then bleeds off.

Any ideas?

 

[imported_lorin]

Re: fuel system question

If the carb bowls are full of gas when you try to start the engine then you can forget about the fuel line, quick disconnect, and bulb being your problem. In other words, with the carb bowls full, even if you disconnect the fuel line, gas should enter the engine if the carbs and motor are OK, so the carbs or motor are not OK . Did you do a compression check? Or look for leaks or cracks in the intake manifold, or broken valves (You need to remove the carbs to inspect the valves).

 

[airwarrior]

Re: fuel system question

Havent checked the vanes.... or compression. I am looking for my compression gauge, and if I dont find it I will go buy one tomorrow... hopefully I can get one that screws in and one person can use

I am wondering, if the vanes are stuck... how can that effect gas not being squirted in?

I am also wondering if the throttle could be a problem? It is a Morse single lever. You pull it out to put in fwd/rev and it has smooth movement either way. However in neutral, it only goes a little up and feels stiff. Maybe it corroded or something (grasping at straws??)

 

[imported_lorin]

Re: fuel system question

If you have a broken valve, when a piston comes down to push gas from the intake manifold up into the cylinder, the gas can just be blown back through the valves into the carb. But I doubt if one broken leaf would prevent all gas from entering the cylinders. If a valve is stuck closed, when the piston goes up to suck gas from the carb into the intake manifold, the valve will not open to allow the gas to enter the manifold. However, there are a number of leaf valves for each cylinder, so one or two of them being stuck (which I've never encountered) wouldn't prevent all gas from entering the manifold. If you dont have a compression checker, you can do a "rough" check of compression by removing the spark plugs and holding you finger tightly over each spark plug hole. You should feel alternating pressure and suction as the engine cranks. You should do this with the ignition disabled (remove the clip from the emergency kill switch). If you're concerned about the throttle valves not opening with the controls, you should be able to open them by hand (just push the linkage to open position) on the motor.

 

[JB]

Re: fuel system question

Go to the Engine FAQs, airwarrior.

Troubleshoot from "Outboard won't start".

Let us know what you find.

 

[airwarrior]

Re: fuel system question

JB I ran the list still "no go", started comparing the faq to the manual and the manual points to the throttle (not being open??), or the problem may be in there. My next pitfall is the manual shows a different controller than what I have (man shows Johnson controls, I have Morse) so I have been trying to find info on Morse on the net.
I wanted to do a compression check, but looked all over and have come to the conclusion I do NOT have a kill switch, so I still need to disable the ignition system for the check, will look in the FAQ's for info on that.
Will keep you informed! Thanks for all the help!

 

[Walker]

Re: fuel system question

To do the compression test on your motor just leave the key in the off position and jump from the Hot battery cable on the solenoid to the small solenoid terminal with the orange/yellow wire on it.

 

[airwarrior]

Re: fuel system question

Thanks Walker! I was reading about doing the comp test and wasn't sure which wires to jump heh heh

I have learned one thing, a servie manual is good if doing an overhaul but doesn't have the information you need to troubleshoot much of anything, it is rather vague. I guess they figure if you are looking in the SM you are tearing it down and don't need to test much heh heh

 

[airwarrior]

Re: fuel system question

Ok.... did the compression test, but I don't know if it was done correctly....

I read in another post, to put it in gear and full throttle, however when I did that and hit the ignition switch nothing happened. So I put her in neutral, and went full neutral, which the lever moved about 1/2-3/4".

Here are my numbers:
Port Upper
114
115
Port Lower
118
116
Starboard Upper
119
129
Starboard Lower
121
121
Now I read somewhere if you are within 10% you are ok, but is that correct and are my numbers high enough?

Walker, my boat had been rewired, and I guess he did the wires on the engine too, as I could not locate a orange/pink wire, they are tan or beige, which if there was one beige wire that would have been close enough for a color blind person as myself.... So I used the ignition switch with the wires moved as far out of the way as possible.

Anyway just wondering what numbers are good, and if the way I did it is ok.

Thanks in advance!

 

[airwarrior]

Re: fuel system question

oops Starboard Lower was:
119
120

NOT 129!

 

[Walker]

Re: fuel system question

Numbers look fine to me.
Try this. Pull the airbreather box off and hold a hankerchief in front of each carb like a curtain. Try to hold it almost touching the carb and have someone crank the engine. See what the handkerchief does. It should pulse in and out from the carb throat.
I just can't imagine why you aren't sucking fuel into the engine.

 

[airwarrior]

Re: fuel system question

Thanks Walker! The Mrs will be back tomorrow, I'll see if she can help.... I was just wondering if the method I used was acceptable seeing as how it did not want to crank in gear.

 

[airwarrior]

Re: fuel system question

okie dokey.... think I azm getting somewhere... the throttle had a good bit of play (slop) once you put her in neutral, before she would open the the throttle plates (butterflies). I am talking about an inch of movement before she would do anything and the safety switch was still in the off position.
I was checking the roller cam and other basic adjustments when I noticed this stuff. I knew the throttle lever itself was sloppy but didnt think much of it as it seemed to be fuel or carb related.

Anyway I need to take the slack out, however, I have a Morse T2 and my Johnson manual only shows the Johnson controls. Before I go tinkering with the cables do you adjust them the same for a Morse controller as you would a Johnson (or other controller?)

This kind of makes sense now, once you add everything up... I am now getting fuel into the engine if I move the throttle up however to get the butterfiles open enough the safety switch drops off onto the second level which I assume is run?

Also is there a way to do the link and sync without putting her in the water?

 

[airwarrior]

Re: fuel system question

feelin brave, gonna play with the cables, will let you guys know what happens!:devil:

 

[airwarrior]

Re: fuel system question

Think I am leaning towards having a mobile boat mech come over and just fix it... what a pain