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Vacuum switch ay

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Billy P

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Can anyone tell me what the vacuum switch ay does exactly? I have a 94 evinrude 150 that runs poorly. Sometimes it runs great sometimes it doesn't. To me it feels like a fuel problem (all electrical components have been replaced), the primer bulb keeps losing its prime when it isn't running good. I noticed today that when I prime the bulb the vacuum switch ay squirts fuel out of a tiny hole on the top of it. Is it supposed to do that?
 
A leaking vaccum switch allows the fuel pump to draw air..... not good!

Purpose of vaccum switch..... grounds out the warning circuit and causes the warning horn to sound steady and constant (same as overheating) if a fuel restriction is encountered.
 
OK. I checked and there was no fuel. I am starting to think my problem is the vacuum switch. When the bulb is primed the motor runs fine but it loses its prime and it loses all power then eventually quits running, I can re-prime the bulb and it will run for a little bit then dies with a flat bulb. Like I said above I noticed when I prime the bulb the vacuum switch sprays fues out of a tiny hole at the top of it.

Thanks for your advice,
Billy
 
Sounds to me like a fuel restriction problem, if your fuel bulb goes flat, maybe a clogged filter, or the bulb is sticking (internal check valve), also your fuel hose conections can be bad, if you have quick disconnects, VRO migh be bad if you pump the bulb and runs good you have a fuel delivery issue = fuel pump???
 
+1 on Nicknack2's answer. Hey Nick.

A bad vacuum switch will not cause the primer bulb to collapse.
In fact, if the vacuum switch was leaking air, the primer bulb would never go flat.
You may have a bad vacuum switch also, but it is only for the warning horn circuit.
You can remove it completely for testing. Pinch off the small hose leading to it with small vise grips.
Just for testing....keep your warning system working after you fix the problem.
 
Billy P said:
Can anyone tell me what the vacuum switch ay does exactly? I have a 94 evinrude 150 that runs poorly. Sometimes it runs great sometimes it doesn't. To me it feels like a fuel problem (all electrical components have been replaced), the primer bulb keeps losing its prime when it isn't running good. I noticed today that when I prime the bulb the vacuum switch ay squirts fuel out of a tiny hole on the top of it. Is it supposed to do that?
Click to expand...

daselbee said:
+1 on Nicknack2's answer. Hey Nick.

A bad vacuum switch will not cause the primer bulb to collapse.
In fact, if the vacuum switch was leaking air, the primer bulb would never go flat.
You may have a bad vacuum switch also, but it is only for the warning horn circuit.
You can remove it completely for testing. Pinch off the small hose leading to it with small vise grips.
Just for testing....keep your warning system working after you fix the problem.
Click to expand...

He did not mention the primer ball going flat, just looses it's prime caused buy a leak at the vacuum switch.
 
Docksidemarineservices said:
Sorry, missed that one.
Click to expand...

It is confusing....what does he really mean? Does he mean "flat bulb" like the bulb is sucked flat, or does he mean it is soft (flat) like it is supposed to be while running?

Hard to interpret some of these posts.

If it is sucked flat, then yes, why would a leaking vacuum switch allow it to suck flat....

It sounds like he is running out of gas due to a fuel restriction to me.
Or, it sounds like he is running out of gas due to a large air leak in the vacuum switch allowing the bulb to go soft (flat) to me.
Or,....what else?

Just pinch off the little hose going to the vacuum switch and you will first see that no gas leaks as you pump the primer, the primer bulb will get firm (a gas leak at the vacuum switch will not let the primer bulb get firm), and then report the results of running test. Also, please clarify exactly what you mean by flat bulb.

THX.
 
sorry for all the confusion. when i say the bulb is going flat i actually mean soft, not sucked in flat. if i reprime the bulb the motor runs fine for a minute or two then loses all power like it is running out of gas and dies. i dont know if this helps but i read in a post from nicknack2(posted in 09) that sounds like the problem i am haveing and someone mentioned if it was a bad vacuum switch the motor would smoke really bad at idle which mine does. i have a vacuum switch on order and am waiting for delivery. i wont be able to run it until this weekend so i will let you all know what happens either with the new switch or pinching off the hose going to the switch.


again, sorry for all the confusion and i really appreciate all the help!

Billy
 
The vast majority of fuel primer bulbs are laying on the deck or transom well in a horizontal position. The nature of the fuel primer bulb is that it is obviously full of fuel at the time it is pumped up hard. Now, as the engine runs, the fuel in the fuel primer bulb will drop down to approximately the halfway mark which is its normal running scenario and no cause for alarm. The only way the fuel primer bulb will stay full is if it is secured in a vertical position with its outlet valve facing upwards.

Replace the vaccum switch when it comes in..... then we'll go from there.
 
Okay, now that you have a good vaccum switch and fuel isn't leaking out of it, you can pump the fuel primer bulb (acting as a manual fuel pump) to supply fuel to the carburetors. If this cures the problem, you have either a failing fuel pump or a ruptured pressure hose leading from the pump to the crankcase.

Test your warning horn..... Engine NOT running, Key in RUN position, Ground out one of the TAN wires you see leading from the cylinder heads.... the horn should sound constant when you ground either of those TAN wires. Or if it beeps once when you turn the key on, that's a normal horn test and you can ignore gounding those wires.

Note that the fuel primer bulb does not normally stay hard when the engine is running. It's normal function is to have the fuel drop down to around the halfway mark of the primer bulb if it is laying in a horizontal position.
 
Thanks Joe. I am leaning towards a fuel pump. There aren't any ruputred fuel lines anywhere, and now my horn goes off while the motor is running. I will look at getting a new fuel pump and go from there.

Thanks for the help,

Billy
 
Yes the beep is every other second. Also it takes about 5-10 minutes with the engine running for the warning horn to go off. During this time when the engine starts to die I can prime the bulb and keep it running. Does that mean I have a bad fuel pump and a bad VRO pump? I know I said I didn't have any ruptured lines, is there a way I can pressurize the system or do I just prime the bulb and look for leaks?

Again thanks for the help!

Billy
 
Also what does VRO stand for? I have been trying to find it in an online manual and cannot find it or a part number anywhere, I know I need the engine model number which is E150GLERA,
 
Variable Ratio Oiling.-------Take the pump apart for inspection and maybe all you need is the repair kit.-----A lot less pennies and easy to do !!
 
Model E150GLERA indicates you have a 1994 150hp Evinrude.

The every other second warning indicates that the VRO pump has failed. A rebuild kit as Racerone suggests is the way to go.

A VRO pump has dual diaphragms and is both a fuel pump and oil pump combined. There is no separate fuel pump.
 
Thanks for ALL the help from everyone! As soon as I can get a new pump or a rebuild kit I will let everyone know how it worked out for me.

Again, THANKS!!

Billy
 
Billy P said:
Thanks for ALL the help from everyone! As soon as I can get a new pump or a rebuild kit I will let everyone know how it worked out for me.

Again, THANKS!!

Billy
Click to expand...

What was the outcome or final fox that solved this issue? I have a 97 150 ocean runner doing same thing
 
Avila-27---This is from 8 years ago-------Too many posts here to read what ----" the same thing "--- is here.--------Start a new thread and explain in detail what your motor is doing / not doing.
 
Have a 150 that has the check engine light and horn going off. The vacuum switch is to me a mystery...the hose going to it has fuel coming out and is not a vacuum. I checked the switch and if I connect it to a multimeter it works fine (closes the circuit)when I suck on the attached hose which leads me to believe it is meant to detect a non-vacuum condition and go off if there is no suction so why is there a hose with fuel coming out of it connected? Is the wrong hose connected I wonder or is there another problem. Runs kinda rough after I adjuisted the carbs, tightened up the main jets and determined one was missing.
 
It detects a restriction in the fuel system between the pump and pickup in the tank.----Pump pulls a high vacuum and triggers the alarm.----Best to investigate.
 
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