Export thread

Hi all. Newb here. Got a CV15S, don't know age. Not much to go on as to model etc. Lt of new parts on ignition. New fuel, tank and tubes. When starting it pops, sputters, may backfire and actually runs pretty ragged. Reduce power from choke position and engine dies. While engine is running, turn off fuel supply. Engine starts running great with no misses. Have not adjusted valve last yet. Replaced carb (and lost old carb when someone came to help and took it) with after market from ebay ($20). I figured float level. Removed bowl and it looks ok but float is plastic so no adjustment available. I Hope this explains my situation. I'm stumped.

Any ideas out there?

thanks
MattGinAZ

I’m guessing aftermarket carb bad, engine running rich. Aftermarket carbs are a crap shoot, unless you buy from reputable dealer.

It is not uncommon to get a Amobay carby that has been assembled with the wrong needle so it never cuts the fuel off properly,

I'd Remove the float bowl off the carb, turn the fuel on, and lighlty push the float up until and/or see if it cuts off fuel flow. or how high it gets before the float shuts fuel off.

Put up the spec. numbers please.

The CV15 is know to have needle/seat problems with the Walbro carburetor that is why a pressure test of the carburetor is done. IF it fails the pressure a new needle and seat are installed per the instructions included in the replacement kit. I have replaced several of these needle seats over the last 7 yrs. The pump fed carburetor are the worst leakers when compared to the gravity fed versions but both can leak.

still working on it. Trying to get float that can be adjusted (replacing 1275702s).

MattXinAZ said:

still working on it. Trying to get float that can be adjusted (replacing 1275702s).

Click to expand...

No spec. number?

Fish said:

No spec. number?

Click to expand...

well, the original carb is missing. There are no tags on engine or tractor. I figure float is 12-757-02-S. CV15s GT2000 craftsman. How ro adjust float level on all plastic float. Going to try a 2575709 wirh metal tang.

Does the tractor have a model number tag?

Plastic floats are adjustable; just got to know how. But as I said most likely you will need to replace the inlet seat and needle valve as it is a known problem that these Walbro carburetors have on the Command and Courage engines. Kit includes instructions on how to replace inlet and correct installed height for the float. OR you can get a copy of and read the instructions per TT-5237.

12 521 03-S KIT; INLET SEAT (GRAVITY) CMD
12 521 04-S KIT; INLET SEAT (PRESSURE) CMD

Kit retail between $44 and $46

Scrubcadet10 said:

I'd Remove the float bowl off the carb, turn the fuel on, and lighlty push the float up until and/or see if it cuts off fuel flow. or how high it gets before the float shuts fuel off.

Click to expand...

I realize this is an old thread, but I'm seeking some clarification on this test procedure. Do you the above ^ with the engine running or off? When Bertsmobile was kindly trying to explain the test procedure to me, the other day, I wasn't understanding what he meant by 'pressurizing the fuel line', and/or whether you do the above test ^ with the engine running, or not. I think he gave up trying to explain it to me after I asked him if you blow compressed air into the fuel line !

StarTech said:

The CV15 is know to have needle/seat problems with the Walbro carburetor that is why a pressure test of the carburetor is done. IF it fails the pressure a new needle and seat are installed per the instructions included in the replacement kit. I have replaced several of these needle seats over the last 7 yrs. The pump fed carburetor are the worst leakers when compared to the gravity fed versions but both can leak.

Click to expand...

Is the 'pressure test' the same thing as the above test-- where you remove the carb bowl and push up on the float? Is that a 'pressure test'? I'd like to do the test-- if I can understand how to do it. Thanks very much for any further explaining. ;-)

Scrubcadet10 said:

I'd Remove the float bowl off the carb, turn the fuel on, and lighlty push the float up until and/or see if it cuts off fuel flow. or how high it gets before the float shuts fuel off.

Click to expand...

I realize this is an old thread, but I'm seeking some clarification on this test procedure. Do you do the above ^ with the engine running or off? When Bertsmobile was kindly trying to explain the test procedure to me, the other day, I wasn't understanding what he meant by 'pressurizing the fuel line', and/or whether you do the above test ^ with the engine running, or not. I think he gave up trying to explain it to me after I asked him if you blow compressed air into the fuel line !

StarTech said:

The CV15 is know to have needle/seat problems with the Walbro carburetor that is why a pressure test of the carburetor is done. IF it fails the pressure a new needle and seat are installed per the instructions included in the replacement kit. I have replaced several of these needle seats over the last 7 yrs. The pump fed carburetor are the worst leakers when compared to the gravity fed versions but both can leak.

Click to expand...

Is the 'pressure test' the same thing as the above test-- where you remove the carb bowl and push up on the float? Is that a 'pressure test'? I'd like to do the test-- if I can understand how to do it. Thanks very much for any further explaining. ;-)

And would you Pro's also suggest purchasing a 'Leak-down Tester' and an 'Oil Pressure Tester' ?? Thanks.

I’d only recommend making a purchase of a leak down tester if you plan on getting into the repair business. I’ve never used an oil pressure tester.

How I pressure test a float carburetor is invert the carburetor; usually with fuel bowl off. Attach a pressure line to fuel inlet and pressurize 5-10 psi using my pressure/vac tester. With the system pressurized wait 30 minutes to see if the standing pressure drops.

As Leak down tester and an oil pressure tester those are usually reserved for shops. I think in the last year I have used my oil pressure tester twice before the current repair job but I will need it again once I replace the oil pump to verify that I resolved the oil pressure lost issue on the Kawasaki motor. Of all things they B/O the pressure regulator spring.

winmod21 said:

I realize this is an old thread, but I'm seeking some clarification on this test procedure. Do you do the above ^ with the engine running or off? When Bertsmobile was kindly trying to explain the test procedure to me, the other day, I wasn't understanding what he meant by 'pressurizing the fuel line', and/or whether you do the above test ^ with the engine running, or not. I think he gave up trying to explain it to me after I asked him if you blow compressed air into the fuel line !

Is the 'pressure test' the same thing as the above test-- where you remove the carb bowl and push up on the float? Is that a 'pressure test'? I'd like to do the test-- if I can understand how to do it. Thanks very much for any further explaining. ;-)

And would you Pro's also suggest purchasing a 'Leak-down Tester' and an 'Oil Pressure Tester' ?? Thanks.

Click to expand...

Save yourself some time and inevitable injury and get it to a qualified service facility.

This is why we discourage people tacking a "me to' on the bottom of an old thread.
It just confuses every one
I was fairly sure I had fully answered your questions
but please have a little think
1) engine will not run with the bowl removed from the carb because the main jet will not be imersed in the fuel
So you do the on engine test while cranking the engine using the battery, spark plug removed so you do not overload the starter.
2) as Star has already outlined, you do the pressure test with the carb off the engine as it has to be upside down so the weight of the float is closing the valve
Most fuel pumps will pump between 5 to 10 psi so the valve has to be able to with stand that pressure
And I am in Australia so way different time zones
I view the forum on a computer & do so while having breakfast and occasionally when using the computer to research parts or write invoices
So some days I might drop in 20 times & other days only once
Add to that I do have a life so was off for 3 days motorcycling

Please download the Kohler service manual and do a basic service
This includes CLEANING the carb & setting the valve lash
Throwing parts at an engine in the hope that you will luck in a solution is a good way to compound your problem an empty your wallet .
I just about urinate in my trousers from laughter with all the posts that start with "I have changed to oil, oil filter , spark plug & air filter but......"
as if changing the oil makes any difference to a problem other than having no oil
In 300 odd services a year I replace about 5 spark plugs and find about 2 air filters so badly clogged that the mower will not start unless it has been tipped over & the filter is full of oil .

I am a little prejudice here as I run a shop and it is how I make my living. I don't mind helping out other techs, just not the local ones for an obvious reason. They are competitors for my income. Plus them don't have any business having tools of any kind. They do more damage than they fix.

I just got in a Gravely ZTR that one of them so called repair shops repaired. They disable all the safeties and got the mower creeping in neutral so when it starts up when it came in it started moving without anyone at the controls. It took awhile to undo the wiring damage. Now off to stop the creeping. The customer that owns the mower now is wanting restore correctly as he runs a youth center where the kids uses the mower.

These mechanics even give the shade tree mechanic a good name. Now I have been called a shade tree mechanic myself as there are times I work under a shade tree. It is just because I am not stupid and know under tree is cooler than working on the asphalt driving driving when it has a surface temp of 140F with air temps nearly 100F and heat index nearly 115F. This morning actually feels cold at 61F. Since I have been very limited to working the last week. I probably will do one mower today even though it is my day off and that I just cross the 63 mark. With my meds I am suppose to stay out of the direct sun so it looking like I got to get a double carport to work under. Then I be a carport mechanic.

Rivets said:

I’d only recommend making a purchase of a leak down tester if you plan on getting into the repair business. I’ve never used an oil pressure tester.

Click to expand...

Thanks Rivets. ;-) Was wondering after reading of the tests being suggested on some threads.

StarTech said:

How I pressure test a float carburetor is invert the carburetor; usually with fuel bowl off. Attach a pressure line to fuel inlet and pressurize 5-10 psi using my pressure/vac tester. With the system pressurized wait 30 minutes to see if the standing pressure drops.

As Leak down tester and an oil pressure tester those are usually reserved for shops. I think in the last year I have used my oil pressure tester twice before the current repair job but I will need it again once I replace the oil pump to verify that I resolved the oil pressure lost issue on the Kawasaki motor. Of all things they B/O the pressure regulator spring.

Click to expand...

Thank you, StarTech !;-) I guess that's something I'll have to skip then, as I don't have a 'pressure/vac tester', nor do I have a 'pressure line', but only a Makita 3 Gal compressor these days, although it does dial down very accurately to low pressures. And I only have the standard 3/8" air hoses w/the quick-connect fittings on their ends. I suppose I could jerry-rig something, but how do you attach 1/4' fuel line to a standard compressor air hose? Anyhoo, sounds like I had best pass on that test !

VegetiveSteam said:

Save yourself some time and inevitable injury and get it to a qualified service facility.

Click to expand...

It's starting fine when cold; runs super great, never even sputters, in fact, it seems to run better now than when it was brand new!
All it's doing.... is not restarting after being shut-off and while still warm. So hardly a need to take it to a service facility, until after I've done several of the typ troubleshooting procedures myself.

bertsmobile1 said:

This is why we discourage people tacking a "me to' on the bottom of an old thread.
It just confuses every one
I was fairly sure I had fully answered your questions
but please have a little think
1) engine will not run with the bowl removed from the carb because the main jet will not be imersed in the fuel
So you do the on engine test while cranking the engine using the battery, spark plug removed so you do not overload the starter.
2) as Star has already outlined, you do the pressure test with the carb off the engine as it has to be upside down so the weight of the float is closing the valve
Most fuel pumps will pump between 5 to 10 psi so the valve has to be able to with stand that pressure
And I am in Australia so way different time zones
I view the forum on a computer & do so while having breakfast and occasionally when using the computer to research parts or write invoices
So some days I might drop in 20 times & other days only once
Add to that I do have a life so was off for 3 days motorcycling

Please download the Kohler service manual and do a basic service
This includes CLEANING the carb & setting the valve lash
Throwing parts at an engine in the hope that you will luck in a solution is a good way to compound your problem an empty your wallet .
I just about urinate in my trousers from laughter with all the posts that start with "I have changed to oil, oil filter , spark plug & air filter but......"
as if changing the oil makes any difference to a problem other than having no oil
In 300 odd services a year I replace about 5 spark plugs and find about 2 air filters so badly clogged that the mower will not start unless it has been tipped over & the filter is full of oil .

Click to expand...

Copy that. I haven't done anything yet. It fired right up yesterday like it was brand new; ran beautifully, not even a sputter, seemingly, as I mentioned above, even better than when it was new. But then, as before, it wouldn't start after I shut it off to blow all the grass off before backing it into the garage. Same as last weekend. Although after it sits for awhile, cooling down, in yesterdays' case....all week, it fired right up - with a wee bit of choke.

I did d'load the Kohler Service Manual last summer, so will read-up on how to set the valve lash, as I have no idea how to do that.
Don't recall anything in the service manual about how to clean the carb, but I did take it off last year when I was replacing the air filter inlet (ABS black plastic inlet), but only sprayed the outside w/carb cleaner & shot some into it both ways as well, which did seem to help. I haven't taken a carb apart--to clean & rebuild--since the 80's. But I will, I guess, if you insist ...as we did purchase one of those ultrasonic cleaners last week (haven't used it yet, so can return it - if recommended not to use), and picked-up some Simple Green concentrate yesterday. Notwithstanding I did read that you prefer the stovetop method, and have a slam-bang recipe for doing so?

Btw, I suppose it'd be a good idea to buy & download the JD 'Technical Service Manual' [TM1756] as well.

winmod21 said:

It's starting fine when cold; runs super great, never even sputters, in fact, it seems to run better now than when it was brand new!
All it's doing.... is not restarting after being shut-off and while still warm. So hardly a need to take it to a service facility, until after I've done several of the typ troubleshooting procedures myself.

Click to expand...

Not trying to be mean here but you don't know how to do any of the troubleshooting procedures and from the sounds of it your mechanical abilities are next to nothing. You are going to hurt yourself. Working with carburetors and fuel is very dangerous if you don't know what you are doing. Don't wait until you're standing next to a burned down garage with your mower in the middle of it and most of your hair gone to take it to a professional.

VegetiveSteam said:

Not trying to be mean here but you don't know how to do any of the troubleshooting procedures and from the sounds of it your mechanical abilities are next to nothing. You are going to hurt yourself. Working with carburetors and fuel is very dangerous if you don't know what you are doing. Don't wait until you're standing next to a burned down garage with your mower in the middle of it and most of your hair gone to take it to a professional.

Click to expand...

Not trying to be disrespectful here but you sure don't know whatever the hell you think you're talking about. I've already done several of the "troubleshooting procedures", as well as replaced entire engines. So "from the sound of it"....your reading skills and assumption abilities are "next to nothing"!
I've also never hurt myself, whether working on tractors or trucks. While I've never claimed to be any kind of expert or pro with engine mechanical services or repairs, contrary to your asinine assumptions, my mechanical abilities are actually quite good, in fact, easily above average, thank you very much.
Nonetheless, I'm quite aware of all the dangers associated with working with fuel. I was simply inquiring about a test procedure that I haven't done and didn't know about; that doesn't mean I was definite going to try to do it; just meant I was curious about it, and trying to assertain if it was a test that I may want to try, or not. As I don't take things to 'professionals' unless I absolutely have to; never have, never will.
Back in the 1980's, when I lived & worked on a 47,000+ acre cattle ranch, when we weren't pushing cattle, or building log bunkhouses & ranch houses, or hay barns, or mending miles & miles of fence lines, or working on tractors or combines or balers or haytools or spreaders or forage equipment &c, or shooting predator cougars or coyotes during calving seasons, or Grouse gunning over our Llewellin Setters, or deer or elk or bighorn sheep hunting, or building fly-rods & fly-fishing, we sometimes worked on our trucks. We had a 47' Ford pickup completely restored, except for replacing the Flat 8 with a Ford 283 out of a 65' Galaxy 500, and replacing the double-clutch tranny with a (T100?) from a 67' 1/2 ton Ford pickup. Also had a 48' Ford F-1, 51' Mercury M, and 52' Ford F-2; of which I rebuilt the carbs on each, the tranny on one, and replaced a lot of other parts on all of them, such as intake & exhaust manifolds & drivelines & suspension & steering parts &c. During the early to mid 80's, I think (13) or (14) of the 45'~47' Fords (no production during WWII) were offered to me for free, for parts, by several Ranchers & Farmers, if I wanted to haul them off, as the 1/2 ton pickup body was the same as the 2-1/2 ton bodies on the big farm & ranch trucks with 18~20 ft flatbeds. Btw, I bought all three (the 48', 51' & 52') from the original owners!....while upland gunning for Sharptail & Sage Grouse.

Moreover, if I didn't know what I was doing....I would've just started messing around with the carb a few weeks ago, without knowing what I was doing, instead of taking the time to come to this great website —whilst patiently asking questions over several days— about our non-restarting issue when the engines' warm. Apparently you've forgotten that that's also one of the main reasons for the existence of this website.
So why don't you run along and try to find someone else to insult and get frosty with, Ol' Sport.

winmod21 said:

Not trying to be disrespectful here but you sure don't know whatever the hell you think you're talking about. I've already done several of the "troubleshooting procedures", as well as replaced entire engines. So "from the sound of it"....your reading skills and assumption abilities are "next to nothing"!
I've also never hurt myself, whether working on tractors or trucks. While I've never claimed to be any kind of expert or pro with engine mechanical services or repairs, contrary to your asinine assumptions, my mechanical abilities are actually quite good, in fact, easily above average, thank you very much.
Nonetheless, I'm quite aware of all the dangers associated with working with fuel. I was simply inquiring about a test procedure that I haven't done and didn't know about; that doesn't mean I was definite going to try to do it; just meant I was curious about it, and trying to assertain if it was a test that I may want to try, or not. As I don't take things to 'professionals' unless I absolutely have to; never have, never will.
Back in the 1980's, when I lived & worked on a 47,000+ acre cattle ranch,
when we weren't pushing cattle, or building log bunkhouses & ranch houses, or hay barns, or mending miles & miles of fence lines, or shooting predator cougars or coyotes during calving seasons, or Grouse gunning over our Llewelin Setters, or deer or elk or bighorns sheep hunting, or building fly-rods & fly-fishing....we repaired tractors and trucks. We had a 47' Ford pickup completely restored, except for replacing the Flat 8 with a Ford 283 out of a 65' Galaxy 500, and replacing the double-clutch tranny with a (T100?) from a 67' 1/2 ton Ford pickup. Also had a 48' Ford F-1, 51' Mercury M, and 52' Ford F-2; of which I rebuilt the tranny on one and replaced a lot of other parts on all of them. Btw, I bought all three (the 48', 51' & 52') from the original owners!....while upland gunning for Sharptail & Sage Grouse.
Moreover, if I didn't know what I was doing....I would've just started messing around with the carb a few weeks ago, without knowing what I was doing, instead of taking the time to come to this great website —whilst patiently asking questions over several days— about our non-restarting issue when the engines' warm. Apparently you've forgotten that that's also one of the main reasons for the existence of this website.
So why don't you run along and find someone else to insult and get frosty with, Ol' Sport

Click to expand...

My assumptions were created when you asked about running the engine with the float bowl off which pretty much took all the assuming off the table. I will make another assumption and assume your original question the way you asked it wasn't exactly what you meant to ask and wish you the best of luck. IMHO though you are barking up the wrong tree with the carb being the issue but then my reading skills could be lacking. I will say as for cleaning the carb, an ultrasonic cleaner and Simple Green is about as good as you can get.