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View Full Version : Kohler CV14S problem !!!!complicated!!!!


mrracer98
05-24-2009, 12:18 PM
Hey all, new to the forum, looking for advise... I am a trained Small engine Mech, though I never worked on the field, just spin wrenches for fun. So I am out of practice a bit...

Question, I am working on a friends Dixon ZTR with a kohler CV14S in it. The problem is this... It Runs GREAT, mows GREAT... though seems once under load and warm, it will just die out. Seems like a fuel delivery problem, as, you can keep it running for a short time longer when it starts, if you put it to full choke. Then after about 5 more seconds, it just dies all together. The warmer it is, the more often it does it.

Here is what it is NOT: It is NOT carb (has been cleaned and rebuilt, I found a spot for a welch plug that was not installed, but you know how carb kits are (for several models) so I left it out as I found it.... It is not a fuel cap/venting issues. Has a new fuel filter, the in tank filter is fine and cleaned. The fuel pump is clean and in great shape, seems to work well.

I am thinking possibly a seal/gasket somewhere that is getting warm, expanding causing a lean condition? Or some sort of electrical condition that once warm, and resistance goes up is causing problems... any help is greatly appreciated... Thanks!

ricky86
05-24-2009, 01:10 PM
That welch plug wasn't missing. They don't use one. Hook an aux fuel tank to the carb to isolate fuel supply from engine. See if that helps. I don't agree with you gkt expansion theory. And you don't know, at this point, if it's the carb or not.

mrracer98
05-24-2009, 01:26 PM
That welch plug wasn't missing. They don't use one. Hook an aux fuel tank to the carb to isolate fuel supply from engine. See if that helps. I don't agree with you gkt expansion theory. And you don't know, at this point, if it's the carb or not.

Only problem with that is I need it running, working (mowing) for about 5-10 minutes before it does it... however when it does do it, if I quick take off the fuel cap, it changes nothing.... ALSO I have completely occluded the cas cap (i.e. covered with rubber so it was air tight) and it still did it no change... I also had the tank completely apart, and the micro screen on the petcock was cleaned and functional...

and FYI: it started last year, and has slowly gotten worse.. i.e. first it would run 30 mins, then do it, then 15, now like 5-10 minutes and it does it... also runs shorter and shorter after each time it is restarted.

You still think it is fuel delivery?

NIXRAY
05-24-2009, 02:05 PM
Could be considerd a stupid question BUT assuming this is an air cooled unit are the 'fins' clean and free of blockage? perhaps its not getting proper cooling and shuting down?

What does the spark Plug look like? (are you sure its the correct heat range?)

~PEACENESS

Restrorob
05-24-2009, 02:28 PM
You still think it is fuel delivery?


Sure sounds like it.

Are YOU the one that rebuilt this carb ?

Is there any fuel in the float bowl the second it shuts down ?

How long doe's it need to sit before it will re-start ?

I see no mention of spark testing during operation (in-line tester) or seconds after shut down ?

As the sticky thread above this section states, Posting model and spec numbers are always helpful ?

mrracer98
05-24-2009, 03:27 PM
OK... Yes I am the one that rebuilt the carb... the carb seems to be functioning flawlessly. It will start nearly right away after it dies... i.e. 5-15 seconds. But as stated earlier, it will run shorter and shorter amt of time after the initial quitting.

spark, I am trying to get a hold of a spark board, as I seems to have lost mine, my friend has one, however when looking at the spark right now (on the plug) it is part blue, part orange, so perhaps a weak spark has something to do with it also.

Model: CV14S
Spec: 1428
Serial: 2319416454

It is a dixson ZTR 4422 it is a walbro carb
Spark plug in it is a Champ RC12YC and on the darker side of chocolate brown and nice and dry.

mrracer98
05-24-2009, 03:29 PM
I will check the float bowl after shut down... and do you know the specs for the coil to flywheel clearance?

Restrorob
05-24-2009, 08:17 PM
Ignition module air gap 0.008-0.012" (0.010")


I just worked on a Kawi yesterday morning that had the same symptoms as this Kohler, Someone else had cleaned the carb but a quick listen sent me to the carb.

I found the problem by checking the fuel level in the bowl at shut-down.

The tip of the low speed idle jet plugged solid, The fuel inlet is larger than the hole for the float needle valve tip and this inlet was plugged nearly closed with rusty trash. Left sitting a few seconds the pump pressure would fill the bowl enough for restart but it would shortly die because there was not enough fuel entering for it to continue running.

A GOOD carb cleaning along with the fuel tank and new filter sent this unit home and made my pocket a little fatter.

mrracer98
05-24-2009, 09:19 PM
Well... I had taken the carb off myself and cleaned it... and believe you me it was CLEAN!!! I usually work and tune motorcycles and snowmobiles... carbs far more complicated than this kohlers... EVERYTHING was taken off that could be, and that was serviceable (less the throttle plate etc). I changed ALL fuel line, flushed the steel line, put all set screws to default factory settings, took the tank, and petcock apart flushed and cleaned both, and everything was high pressure cleaned with air compressor as well...

HOWEVER, the coil gap was only about 0.002" and rusty, I cleaned off the rust on the coil and the flywheel that gave me about 0.0035-0.004" gap... Seems to work better now. I cannot get it to repeat it after that. I know a hot coil gives more impeadence, so perhaps this was the reasoning behind it all? I am not sure it is kind of frusterating, but I am thinking this fixed it.

I checked compression... 188 PSI. lol so that is fine.

laboredm
05-24-2012, 08:13 AM
I have the same problem with my Kohler. I have tested all and I know that there is no spark is my problem. I have an inline spark tester and I have good spark when the engine is cold, I got the engine to run for 1/2 hour and ran out of gas. Filled the tank and now hot there is no spark. cleaned everything. What would cause there to be no spark when hot??????

Restrorob
05-24-2012, 12:02 PM
If you read this whole thread you seen I had to ask the OP to post numbers, Without those it's a crap shoot......

laboredm
05-24-2012, 12:43 PM
The engine is a CV14s. I have not checked the air gap but the engine does start when cold so not sure if the air gap will change when if gets hot. I know that it is a spark problem. Can the ingition coil fail when warm?

Restrorob
05-24-2012, 05:15 PM
not sure if the air gap will change when if gets hot.

Nope.....



Can the ingition coil fail when warm?


Yep......

Disconnect the white kill wire from the coil and check for spark again, If still no spark replace the coil. Gap to the spec I gave above.....

VegetiveSteam
05-30-2012, 11:34 AM
Well... I had taken the carb off myself and cleaned it... and believe you me it was CLEAN!!!

HOWEVER, the coil gap was only about 0.002" and rusty, I cleaned off the rust on the coil and the flywheel that gave me about 0.0035-0.004" gap... Seems to work better now. I cannot get it to repeat it after that. I know a hot coil gives more impeadence, so perhaps this was the reasoning behind it all? I am not sure it is kind of frusterating, but I am thinking this fixed it.

I checked compression... 188 PSI. lol so that is fine.

Well if the other guys on here are anything like me they don't believe anything unless they see it with their own eyes. I'm not sure about your 0.0035-0.004 air gap when Rob in his last post told you it needed to be between 0.008-0.012.

188 pounds of compression?????? That can't be. I don't feel compression has anything to do with your issue but there is no way that engine can have 188 pounds of compression. I'd believe 88 but if you had 188 pounds of compression that little inertia drive starter wouldn't even come close turning that engine over. Everyone here is of course trying to help but when we read things like 188 pounds of compression it makes us wonder if the person we are trying to help really knows for sure what they are doing.

I guess all I can say is if the 0.004 air gap fixed it then that's good.

piston slapper
05-30-2012, 07:48 PM
Steam.....the numbers are all over the place...and yet...he got it running...
He is undoubtably in touch with his inner mechanic......
Trust The Power
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