GT225 w/ Kohler CV15S engine - starts ok; runs & mows great, doesn't sputter or die; but once turned off...won't restart. FIXED !=))

[winmod21]

Hello to all --
Any help will be much appreciated. I believe it's the original Walbro carb (# 75 3349 1205393). Last year it had a broken fuel solenoid wire and was having starting problems, and some very helpful gentlemen here suggested that I forget about the wire, and cut-off the little spring-loaded vertical rod at the top of the fuel solenoid; then to compensate, let the engine idle for approx 30 secs before shutting it off (to compensate or counteract for the fuel solenoids' spring-loaded vertical rod being cut off), (couldn't find the thread).

Anyways, that worked great last summer. But now, the Kohler CV15S is starting okay (sometimes a little hard), and is currently running super great & strong (Skookum !=) without any sputtering or dying. But when I do need to shut it off, for whatever.... then it will just crank & crank & crank, and after a few tries....smell like it's flooded; then if I continually try, cranking it over & over, it'll occasionally make a very loud backfire, followed by a few more intermittent backfires, before eventually starting-up again, though very roughly at first, by which time I'm about to give up for fear of discharging the battery too much.

I do have a spare carb that I purchased last year from SES, but didn't install it - as I was hoping to just use the fuel solenoid off of it, but the fuel solenoid was different (shorter, squatty one - prob fr China), and wouldn't screw on due to the little black wire connector box on the side of the fuel solenoid. So that's when I decided to cut the spring-loaded vertical rod off the top (where it screws into the carb bowl) of my orig fuel solenoid. Which again, helped with poor starting issues, but now I'm having the 'won't restart' problem :~\ ...after mowing for awhile.

Thinking of putting the new carb on . . . but after doing so, are they hard to fine tune for idling & running &c?

Apologies for my long-winded rambling. Any ideas will be welcomed greatly !;-)
Jack

 

[sgkent]

12853178S was the factory carb you needed based on your prior post. Be sure to check it against your model and serial number before buying one. Your model shows it has a fuel pump too. Sounds like it is too rich after being shutoff. Make sure the air cleaner is clean. I only use factory carbs when I replace one. Lowest price I saw for a genuine one was $140. Good luck.

 

[winmod21]

12853178S was the factory carb you needed based on your prior post. Be sure to check it against your model and serial number before buying one. Your model shows it has a fuel pump too. Sounds like it is too rich after being shutoff. Make sure the air cleaner is clean. I only use factory carbs when I replace one. Lowest price I saw for a genuine one was $140. Good luck.

Thanks sgkent !;-)
Yes, that's the carb I ordered last year, but haven't installed yet. It is the Kohler replacement; was $165 @ SES.
I haven't touched or checked the fuel pump, other than fuel flow to the carb does look good. I do clean the air filter almost every time I mow; replaced it last year; the green outside foam is looking a little dirty-- so time to wash it again. Originally Scot and Native American here too ;-)

 

[bertsmobile1]

Sound really like the carb float is not doing it's job
There is a specific range of air to fuel ratios that will burn at compression pressures .
IF it does not burn it will accumulate in the muffler and when the air: fuel ratio in the muffler is right and there is some ignition source then the fuel in the muffler will ignite.
If not it will accumulate , condense and dribble out.
If the carb is flooding badly then liquid fuel will ooze out of the carb run down into the cylinder & be blown out the exhaust unburned because only gasses can burn .

 

[winmod21]

Sound really like the carb float is not doing it's job
There is a specific range of air to fuel ratios that will burn at compression pressures .
IF it does not burn it will accumulate in the muffler and when the air: fuel ratio in the muffler is right and there is some ignition source then the fuel in the muffler will ignite.
If not it will accumulate , condense and dribble out.
If the carb is flooding badly then liquid fuel will ooze out of the carb run down into the cylinder & be blown out the exhaust unburned because only gasses can burn .

Hi Bert ! Hope all is well with You & Yours down under.
You know, that sounds exactly like what is happening and what the condition/issue is ! Everything you described there...is what it feels and sounds and smells like is happening! What am I to do ?;-)

 

[winmod21]

. . . I went and ordered an ultrasonic cleaner today (even though there's massive amounts of reviews stating that they all pretty much quit working or break after awhile :~\), and figured I'd try cleaning the carb — and seeing if that helps it start better, before resorting to installing the brand new Kohler replacement carb [#12 853 178-S] that I bought last year — although I've yet to find out if put the whole carb in it, or if I should take the carb apart first? Or not put some parts of it in the Ultra-cleaner? How do you recommend cleaning them? And may that possibly fix a sticking float? Thanks again ;-)

 

[bertsmobile1]

take the carburettor off and clean the float needle & seat
I like to remove the float bowl while it is on the mower & check that the fuel stops flowing well before the the float touches the carb body
Off the mower I flip them upside down and pressurise the fuel line .
I have found that is the weight of the float holds around 7psi then the float will work in the engine.

The caveat to this is some carbs are designed to work with gravity feeds and others are designed to work with impulse pumps while others still work with mechanical pumps and all of these have different cut off pressures .

 

[winmod21]

1--- take the carburettor off and clean the float needle & seat
2--- I like to remove the float bowl while it is on the mower & check that the fuel stops flowing well before the the float touches the carb body
3--- Off the mower I flip them upside down and pressurise the fuel line .
I have found that is the weight of the float holds around 7psi then the float will work in the engine.

4--- The caveat to this is some carbs are designed to work with gravity feeds and others are designed to work with impulse pumps while others still work with mechanical pumps and all of these have different cut off pressures .

Thanks,
1--- Do those things instead of the ultrasonic bath?
2--- When I do that, with the engine off, I get maybe 3~4 tablespoons of gas in the plastic bowl I set below carb before unscrewing the fuel solenoid. After screwing the fuel solenoid back in (btw, should the fuel solenoid be causing the bottom of the bowl to concave upwards ?:~\ ), the engine seems to always start within a few more attempts. But are you talking about removing the bowl with the engine running...and then pushing the float up against the carb inner body with your finger...to see if the engine starts to sputter due to the fuel being cut-off by doing so ? Not sure I comprehend ya there ;-)
3--- "pressurize the fuel line"....(ehem, with a 'z' ;-).... all the way back to the tank?
4--- Our Kohler CV15S is a mechanical, I think.

. . .gotta scoot for dinner; be back later Thanks again!

 

[bertsmobile1]

We are talking about removing the float bowl, cranking the engine while holding the float up with a finger.
Spark plug removed & grounded on the far side of the engine to avoid fire because you will be spilling fuel. so near an open door or outside.
pressurising the CARB fuel line. all we are trying to do is check that the float is cutting off the inlet .
If yours has a mechanical pump then ( from memory ) it will have a longer needle than a gravity or impulse carb
And by longer we are talking 0.005" to 0.010"

 

[winmod21]

We are talking about removing the float bowl, cranking the engine while holding the float up with a finger.
Spark plug removed & grounded on the far side of the engine to avoid fire because you will be spilling fuel. so near an open door or outside.
pressurising the CARB fuel line. all we are trying to do is check that the float is cutting off the inlet .
If yours has a mechanical pump then ( from memory ) it will have a longer needle than a gravity or impulse carb
And by longer we are talking 0.005" to 0.010"

Okay. Not clear. Leave spark plug in spark plug wire and ground plug with something like an alligator clip to frame? As I only have two hands. Btw, plug is already on far side of engine. And not sure how I'd hold the float up whilst cranking engine, cuz if I'm not mistaken, one needs to depress the brake pedal safety switch -- which is on the other side from carb. And does the engine crank with the seat safety switch not being sat on? I'm a bit fuzzy on those things, but will try to catch up !;-)