[Old_fart]

My Simplicity Sunstar with the Kohler M20s Magnum was purring like a kitten until.....I tried to hook up an extra spring to the throttle linkage to let it idle down when warm. It had a habit of running FAST on throttle idle position, as if the linkage was binding and holding the throttle open.

Anyway, with the air cleaner off, I tried to sanitize the Shutdown Solenoid wiring a bit; it had been spliced a couple of times, and the ground contact looked dirty.

Put it all back together, and the engine would barely fire for a couple of seconds, then die as if starved of fuel. Didn't really do anything, and now it won't run!! ****** Off!

Took the air cleaner off, looked at the Shutdown wiring again, looked all intact, decided to actually remove the solenoid; the solenoid came off, but the plunger stayed in the carb, and it didn't want to pull out. IS THAT NORMAL? I didn't force it out, checked power and ground again, all good, and put it back together. Also checked fuel flow to carb, all good. Remember, the tractor ran like a top where I parked it.

Tried to start it again, SAME THING, only this time I learned that it would start with throttle completely closed and NO CHOKE, and would sit there and run at a low idle. Never did that before. But as soon as I cracked open the throttle a tiny bit, it dies. ALSO, when idling like this, the choke has NO EFFECT at all, I can leave it open or shut it completely, no effect. Open the throttle, and it dies.

It SEEMS like it's running on the idle circuit in the carb only, and as soon as the throttle demands more fuel, it dies. Could this be my Shutdown solenoid not working and staying closed?

What in the heck did I do by adding a spring and cleaning up the Shutdown solenoid wiring that would cause it to suddenly run like this? HELP!

 

[Whirly]

My Simplicity Sunstar with the Kohler M20s Magnum was purring like a kitten until.....I tried to hook up an extra spring to the throttle linkage to let it idle down when warm. It had a habit of running FAST on throttle idle position, as if the linkage was binding and holding the throttle open.

Anyway, with the air cleaner off, I tried to sanitize the Shutdown Solenoid wiring a bit; it had been spliced a couple of times, and the ground contact looked dirty.

Put it all back together, and the engine would barely fire for a couple of seconds, then die as if starved of fuel. Didn't really do anything, and now it won't run!! ****** Off!

Took the air cleaner off, looked at the Shutdown wiring again, looked all intact, decided to actually remove the solenoid; the solenoid came off, but the plunger stayed in the carb, and it didn't want to pull out. IS THAT NORMAL? I didn't force it out, checked power and ground again, all good, and put it back together. Also checked fuel flow to carb, all good. Remember, the tractor ran like a top where I parked it.

Tried to start it again, SAME THING, only this time I learned that it would start with throttle completely closed and NO CHOKE, and would sit there and run at a low idle. Never did that before. But as soon as I cracked open the throttle a tiny bit, it dies. ALSO, when idling like this, the choke has NO EFFECT at all, I can leave it open or shut it completely, no effect. Open the throttle, and it dies.

It SEEMS like it's running on the idle circuit in the carb only, and as soon as the throttle demands more fuel, it dies. Could this be my Shutdown solenoid not working and staying closed?

What in the heck did I do by adding a spring and cleaning up the Shutdown solenoid wiring that would cause it to suddenly run like this? HELP!

remove that spring u added.. then see if it runs..

 

[Old_fart]

remove that spring u added.. then see if it runs..

Forgot to clarify that I DID remove the spring...I could see that it would screw up the governor function.

With spring removed, engine would only run with throttle in idle position (closed), choke has no effect open or closed. My next step is to remove the Shutdown Solenoid plunger completely and see if it runs then.

 

[tiretrx]

I would verify that the fuel solenoid is indeed working. If so, check fuel delivery, inspect and thoroughly clean the carb.

 

[Whirly]

I would verify that the fuel solenoid is indeed working. If so, check fuel delivery, inspect and thoroughly clean the carb.

he can do a simple test & that is to listen very carefully when he turns on the IGN switch.. there should b a lil 'click' from the ABF solenoid.. he can do this with it off to make sure it is movin too..

 

[deereboy55]

Reminds me of my dad's favorite quotes,,,If it ain't broke, don't fix it,,,,,my brother and I ,like to take things apart when growing up.

 

[no2498]

the solenoid came off, but the plunger stayed in the carb, and it didn't want to pull out. IS THAT NORMAL? I didn't force it out, checked

you need to get this working
it stops full gas flow to the carb

john

 

[MDStout]

No. The plunger should not stay inside the carb.
Get that out of there and it should fix your problem.

 

[Old_fart]

It fixed itself (for now).

I took it all apart again, checked all the connections (again), but this time I pulled the plunger out of the carb (was a little sticky, but came out) and tested it by turning on the key and seeing if it snapped into the solenoid. It did.

So I put it back together and it ran great (again).

I guess it either decided to stick right then and there the first time, or the elec connection didn't ground right then, whatever, but now I know the symptoms if it fails!

Thanks for hearing my rant!

 

[tomw0]

Old_frat...: the plunger out of the carb (was a little sticky, but came out)

If it is sticky, then you have a 50:50 chance for it to stick open or stick closed. It is washed in fuel, so should not be sticky.
Were it mine, next time it fluffed, I'd be taking the ABF solenoid & valve apart and cleaning it, and the opening in the carb, with carb cleaner to get rid of the 'sticky' factor.
It should be free to move in either direction if it is to work properly.
Note that this valve will NOT stop fuel seeping into the carb if the float valve leaks. All it does is partialy block flow such that the engine cannot run above idle speed if at all, and keep the engine from pulling raw fuel into an engine still spinning down to a stop and the consequent backfire.
tom

 

[(username)]

I don't really understand the purpose of the solenoid. I mean, why bother? Shouldn't you just idle down before you shut the engine off, anyway? And if you want to turn the engine off that badly, then pull the choke, or just turn off the key. Or both. Old_Fart, as for your problem, I think the rest of the gentlemen here have summed it up for you pretty well.

 

[rhenning]

The solenoid keeps the engine from backfiring when you turn the key off on an engine that was running and has a hot muffler. Roger

 

[85lebaront2]

That is the story that is given, but I have a number of older (Pre-EPA) engines without them and never get backfires.

Due to EPA regs, small engines are now covered starting in the mid 90s. Removing it is technically a violation, but since the other side of the stupidity is parts are not available to repair these, even replacement solenoids on many Kohler carburetors.

The solenoids are in the worst possible place with the ethanol enriched gasoline, the water that accumulates ends up right there.

 

[(username)]

I was going to say, I have a Kohler Magnum 20 that doesn't ever backfire, and it was built without a solenoid. You just need to turn the throttle down and let it run for 5-10 seconds before killing the ignition.

 

[tomw0]

Let me say this about that, one thing perfectly clear.

If the engineers didn't need it, they would not have put them on. If you check replacement prices(if you can find the one you need), they are EXPENSIVE. The majority of a $100 bill would be et up buying one.
That is not something you install on 10,000 engines just for fun.
It is certainly possible to remove the ABF solenoid valve and replace it with a bolt, on a LOT of carburetors, but not all. At least some Nikkis used on AYP/ Kohlers has a metering jet build into the ABF, and if left out, will give the engine so much fuel it will continue to burn in the muffler to the amusement of small boys and dogs...
I am uncertain of my course of action if it fails. I thought it was intermittently failing, and used some paperclip wire to keep the passage open, so it can be sort of bypassed if it totally dies. I'll wait to cross that bridge.
tom

 

[(username)]

I didn't know some of them have jets built into them. It always seemed to me that the solenoid was added as a kind of fail safe for the ignition.

 

[85lebaront2]

Let me say this about that, one thing perfectly clear.

If the engineers didn't need it, they would not have put them on. If you check replacement prices(if you can find the one you need), they are EXPENSIVE. The majority of a $100 bill would be et up buying one.
That is not something you install on 10,000 engines just for fun.
It is certainly possible to remove the ABF solenoid valve and replace it with a bolt, on a LOT of carburetors, but not all. At least some Nikkis used on AYP/ Kohlers has a metering jet build into the ABF, and if left out, will give the engine so much fuel it will continue to burn in the muffler to the amusement of small boys and dogs...
I am uncertain of my course of action if it fails. I thought it was intermittently failing, and used some paperclip wire to keep the passage open, so it can be sort of bypassed if it totally dies. I'll wait to cross that bridge.
tom

Tom, if they actually sold the cut-of solenoid for my CV22S, I would consider buying one. The only way it is sold is a complete Nikki carburetor, at $384, I pulled the **** thing off and cut the tip off the plunger. I have two MV series Kohlers that never had one, two Briggs twins, one of which is a 1999 model, neither of them have one, one Tecumseh HH100 and a Tecumseh OV691EA, The last Tecumseh has two solenoids one on each carb, the others do not, and none backfire when shut down.

 

[tomw0]

I have two Commands ... and one has a Nikki one has a Walbro.

The Nikki has a solenoid, the Walbro does not.

The Walbro gasket & seat set was pretty close to $15.
The Nikki gasket & seat set was pretty close to $50.

I suspect the carbs could be swapped with little difficulty, but haven't looked.

Neither one backfires when shut off. The solenoid, as I remember, was more than $50 when I checked during trouble shooting.

Why is it there? *Some* engineer decreed it to be so. Perhaps a Sears buyer? I dunno. Perhaps Kohler got a 'deal' on some Nikkis that had ABS's and pawned them off on Sears? I do know that engineers will try to minimize parts count and cost, and for the most part, won't require unnecessary parts. I have seen year over year de-contenting of some cars. Mostly interior bits and pieces are either simplified or substitution with less 'feature' is made.

The one thing I do know: Nikki is sure proud of their parts. They must think they are made of precious plastics and cork and fiber, and a noble metal for the needle...
If the solenoid dies, I'll likely try to figure out a method to gut it, more or less.