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Discussion Starter · #21 ·
Naplesjoe...what you can do is put a fuel shut off valve fairly close to the carb and just use it and allow the engine to run out of fuel
 

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Naplesjoe...what you can do is put a fuel shut off valve fairly close to the carb and just use it and allow the engine to run out of fuel
I guess you could do that. But I prefer things to works as they were intended. I haven't had enough experience with this engine (Command 20) to say its a common problem. Apparently it is. My point was although Taryl's video's are very good sometimes his advice is not always spot on. But who's is?
 

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Discussion Starter · #23 ·
Actually the needle valve is a somewhat common problem ..there really is no reason to remove the solenoid, unless it has stopped working...which means that it is not retracting when the key is turned on...contrary to a lot of peoples' belief...it does not control the flow of fuel into the carb...just within it
 

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Actually the needle valve is a somewhat common problem ..there really is no reason to remove the solenoid, unless it has stopped working...which means that it is not retracting when the key is turned on...contrary to a lot of peoples' belief...it does not control the flow of fuel into the carb...just within it
I never thought it to do anything other than shut off the fuel. I would guess the design of the carburetor has something to do with that. Not ever having to take one apart I couldn't say for sure but apparently their is something other than a standard float in these carbs. And that allows fuel from the pump to continually flow into the engine as it coasts to a stop. I do know this. Mine was intermittent. It did cause starting issues as no fuel was reaching the carb and when I cut the needle off (very reluctantly)it started fine but the run on I described above is something I won't tolerate.

I do notice the engine idle speed specs seem quite high. And more than one post suggests its should be above 1000 RPM's where it is now. Once I get the parts for the carb. (slow boat from China) I intend to turn that down to something around 700. I think that has a lot to do with the run on issue.
 

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One of the best things you can do for a carb (especially with ethanol blended fuel) is install a shutoff valve and let the carb run dry before long-term storage.

Mike
 
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Discussion Starter · #26 ·
@Naplesjoe...you can order just a new solenoid..which will solve that problem the way it was originally intended..I am curious ...what was going on with it that gave you the idea to cut it off?
 

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@Naplesjoe...you can order just a new solenoid..which will solve that problem the way it was originally intended..I am curious ...what was going on with it that gave you the idea to cut it off?
The solenoid was hanging and intermittently staying closed , which caused (of course) the engine not to start. Once in maybe ten start attempts it would. A light tap on the coil usually solved the issue at least temporarily. I have read on numerous posts that this is a common issue. And I knew a replacement could easily be purchased. In fact I purchased an entire new carb. Just haven't gotten around to installing it yet. All is fine with moderate use of the tractor and its only after a long high power use that the run on condition shows it's nasty head.

Once I took the drastic step of cutting the stem off, the engine pops off every time just as it should. That would be proof enough to me that it was the issue. I however do prefer things be as they should and I intend to install the new carb. soon.
 

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I'm with you on that, you need to be able to turn the engine off quickly sometimes (for safety).

My comment about adding a fuel shutoff is more for preservation of the carb over time.

Mike
 

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I'm with you on that, you need to be able to turn the engine off quickly sometimes (for safety).

My comment about adding a fuel shutoff is more for preservation of the carb over time.

Mike
Your correct with shutting the engine down quickly but it raises a question I've been thinking about. And that is why does this engine need that solenoid in the first place. I haven't disassembled this carb yet but wonder what is different about it? Perhaps something other than a standard float? Few if any other engine requires this. What worries me most is that I suspect the engine is actually running in reverse when this happens. It certainly don't sound good. Perhaps somebody has a good explanation.
 

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Discussion Starter · #30 ·
The solenoid is typically seen on a tractor on which the fuel tank is above the carburetor and there is no fuel pump...however they are on some with fuel pumps also
Main purpose is to stop after fire (some call backfire) when you turn key off. When you remove spark (key off), you still have fuel dumped into the intake, which travels un-burned to the muffler ...which causes a loud noise...no unusual floats or anything else
 

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There's some info online. Apparently, Kohler did this to avoid backfiring.

Mike
 

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The solenoid is typically seen on a tractor on which the fuel tank is above the carburetor and there is no fuel pump...however they are on some with fuel pumps also
Main purpose is to stop after fire (some call backfire) when you turn key off. When you remove spark (key off), you still have fuel dumped into the intake, which travels un-burned to the muffler ...which causes a loud noise...no unusual floats or anything else
This is not backfire. It is definitely run on. (Dieseling) After digging through various versions of this engine I have found none that don't incorporate this solenoid. Perhaps Kohler simply felt it didn't hurt anything if not required and just standardized it. I'm leaning on something with the head design that makes these engines need a little help. Dieseling would certainly indicate that. Way back in 63, Chevy installed two head gaskets on their 409's to eliminate that very thing. I know I had one and I did take one out with virtually the same results. Not saying the compression ratio is that high in a lawn mower engine but perhaps a thin or sharp area in the combustion chamber. Something is igniting that fuel after the spark is eliminated. Perhaps fuel quality?

I also should have mentioned that I experimented with this a bit by clamping a vise grip on the fuel line between the pump and carb and let the engine die from full throttle. The two times I've done this, no run on. But, then again it doesn't always do it under normal operating conditions.

I will install the new solenoid soon and see what happens.

Just to remind folks, my original mention of this was to point out I didn't always find Taryl's advice 100% accurate. As is the case with anybody else's I guess. I have a similar thread going over on WFM and will continue there.
 

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Gotcha. Depending on the job, but especially with carbs (my least favorite thing), I usually watch multiple videos from different sources before attempting the repair.

Of course, I've mentioned this already, lol...

When I'm needing advice, I'm open to any source of info, and often watch several on the same topic before tackling the job, as different folks will come at a problem differently. At the very least, you'll usually get to see different camera angles and hear different ad-lib comments that can make a huge difference.
Mike
 
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Discussion Starter · #34 ·
There's some info online. Apparently, Kohler did this to avoid backfiring.

Why they need it and Briggs doesn't in the same tractors is anyone's guess...

Mike
I have to double check tomorrow...but I am fairly certain that on my Broadmoor with a Vanguard, that it does have the solenoid
 

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You know, I might be way off on this. I will say that I don't recall hearing as many problems with the Briggs ones, though. Maybe my tractor wasn't old enough to develop a problem.

I fixed my prior post...

Mike
 

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Discussion Starter · #36 ·
Some causes of dieseling are bad timing ( but I think there would be trouble starting) and carbon build up in the cylinder
 

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Some causes of dieseling are bad timing ( but I think there would be trouble starting) and carbon build up in the cylinder
Another is fast idle settings. (In most engines) When I install the new carb, or solenoid I'll try slowing that down. Do a little experimenting. The book calls for 1200 RPMs and that seems a little high in this tractor. This engine is a recent install in a JD 317. I have always set the idle on 317's around 750 with the "K" and Magnum engines. This high idle speed really exacerbates any creeping in neutral. This tractor has a little of that but not enough to tear into things.
 

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I recently installed a complete new carb with the solenoid attached. Shut down issues were solved only to create another. The new carb now seems to loose fuel and make for very hard starting after a period of time. I guess I traded one problem for another. I should have been more careful purchasing it. I saw it on Ebay, it was less than thirty bucks, had a very nice picture of an American flag on the post. A promise of fast delivery. Well, four weeks later the **** thing showed up from China. I guess when I have a little time I'll install the new solenoid on the old carb. Then if that fails, do what I should have in the first place and buy a genuine Kohler replacement.
 

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Some causes of dieseling are bad timing ( but I think there would be trouble starting) and carbon build up in the cylinder
Pretty hard to be a timing issue as these engines are pretty much fixed with the mag coils mounted more of less solid.
Some of the higher end Kohlers have a spark advance system. This one does not.
 
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