a simple check of the primer solenoid?

bob johnson

Rear Admiral
Joined
Feb 25, 2009
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4,306
if i pull a gas line hose off the primer solendiod and push the key in , wiill < or am i supposed to....see gas squirt?

I SUSPECT my primer isnt giving me the fuel like it is supposed to...

ALSO, how is the operation described??

I know you are supposed to push the key in to prime the motor rpior to starting...but ther eis that red lever

is the lever a by pass for PUSHING the key??

if the electrical of the primer isnt working...will turning the lever up....over ride the bad electrical???

1995 J115SLEOC

thanks

bob
 

Joe Reeves

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Feb 24, 2002
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13,262
Re: a simple check of the primer solenoid?

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.

The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.

Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.

Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.

Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.

Bottom line..... Look upon the primer solenoid as an electric choke.
 

emdsapmgr

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Dec 9, 2005
Messages
11,551
Re: a simple check of the primer solenoid?

Looks like Joe beat me to the answer. He's got a great explanation... The red lever should always be in the run position, unless you are injecting something through the schraeder valve at the end of that red lever. (That would be: fogging the engine for the season, or injecting Engine Tuner.) The lever should always be parallel to the length of the solenoid. Yes, you should be able to prime the fuel hose bulb, then pull the primer hose off the top carb, then turn the key to on,-then push in on the key. You should see fuel pulsing out the end of the hose. If you pull the hose off the solenioid, be very, very careful when trying to reinstall that hose. Those hose barbs on the plastic solenoid cap are extremely delicate and break easily-so do your test by pulling the hose off the brass hose barb on the carb.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: a simple check of the primer solenoid?

great tip on pulling the hose of the brass barb.... so there is no need to PUMP the key by pushing in and letting go over and over...

just the act of pushing in the key and holding...is sufficient...right

and the longer i hold the key in, the more gas that goes through the soleniod to the manifold by pass... right??


so this week i ll look into the solenoid and the length of gap my spark will jump.....

bob
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: a simple check of the primer solenoid?

ok I did a few checks and tests today....

compression 120 13, 130 130, thats good!!

spark ..the top two cylinders have spark that will jump 1/2", but the bottom two wouldnt..i had to screw the gap down to about 3/8ths an inch to get the spark to jump...

I checked the primer and it isnt working....pulled a hose from the manifold and nothing happens when the key is pushed in...but if I turn the red primer lever upwards, and squeeze the gas line bulb...i get a strong stream of gas shooting out...if i turn the lever back to normal....and squeeze the bulb...nothing happens and the bulb is solid....


so i turned the lever up and squeezed the bulb..and tried to start the motor...it seemed like it wanted to fire, but wouldnt...did that a few times...then turn the lever back to normal.( but didnt bother trying to prime... and just tried to start the motor....2 tries and she fired up...

so it seems my method until i replace the primer solenoid, is to turn the primer lever up and try and start a few times squeezing the bulb once in a while, then turning it back and starting...


i have two other motors that i can scavenge the solenoid off of, and luckily one is totally apart and it is just sitting on the shelf..

then i have to try and figure why the spark is weaker in the bottom two cylinders... i have extra coils on the shelf as well as power packs...

bob
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: a simple check of the primer solenoid?

Generally, the coils are pretty reliable. You could have a coil problem since the coil packs are a dual setup on your engine. Good that you have some spares...!
 
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