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Kohler CV22 hard starting when cold

7193 Views 61 Replies 10 Participants Last post by  dave_r
I have a Snapper 52" hydro, with a Kohler CV22 Spec 75512. I've fashioned a plow attachment to replace the deck, for use during the winter, and it works pretty good.

The problem I'm having is getting the engine started. The battery it came with was pretty old, and likely only was spec'd to have enough power to start the engine when it was warm out (like say, +10C). I bought a small car battery, fabbed a new mount for it, and now it spins over great.

I would say when it's about -10C or so (or warmer) out, it'll start.

But once it gets colder than about -15C, I have to give it ether to get it to fire, and put hand-warmers (you know, the "expose to air to activate" ones) packed around the carb. Then the engine will run, until the hand-warms cool off.

I did take apart/clean the carb about a month ago, it was very clean inside (no crude in the float bowl at all) except for what I believe is the accelerator pump (all the crude was on the non-fuel side of the rubber "pump").

I only run Premium non-ethanol gas, and during the winter, I add gas antifreeze and some methyl hydrate to it, and occasionally a bit of Seafoam.

I have modified the intake from stock, in that I took off the original air filter assembly (everything ahead of the carb), and use the external 2-stage Donaldson filter setup from another revision of the CV22, and bypassed the fuel pump (the fuel tank is physically higher than the carb, so it still gets fuel fine).

I am going to swap back to the original intake setup, as the plastic housing over the air filter mates pretty closely to the cover of the engine, and some of the warm air gets blown under that housing, so that might aid with keeping the carb a little warmer (both directly and with warmer air going through the carb).

This change might help with keeping the engine running once it's started (as it will eventually stop without the heating pads on the carb), but it won't help with getting the engine started in teh first place. It seems something freezes shut and the engine gets no fuel until that something gets a little warmer (not necessarily above 0C, but it needs to be around -10C or warmer).

Any ideas on what the problem could be? The only thing I've got is that maybe the fuel-shutoff solenoid is faulty (it did function correctly when I tested it during the carb cleaning). I can't tell if it activates or not, either by listening for it or by feel (I tried engine off, and turning the key from off to on, couldn't heard or feel anything).
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Just to follow up, it was about -20C earlier this evening and it spun fine, and did start after a fair bit of cranking. It would spin and then try to run for a longer and longer period of time (and then I would try starting it again), until it actually caught and run fine.

I also got ahold of Scott at Kohler (after getting forwarded to him from Kohlers twitter account), and he said they didn't have an anti-freeze kit for this engine as it was made for a summer job, but said that the best thing to do would be to get warm air from the exhaust to the intake.

So, I initially came up with just removing the heat shield from the exhaust, then fabbing a shield around the exhaust, up to just inside the bottom of the air filter cover. But then, as I was thinking about how it really wouldn't get a lot of hot air from over the exhaust into the intake (it would be better, just not that great), I came up with the idea of putting a hole in the heat shield, welding a short tube over that hole, making a plate that goes underneath the carb (mostly horizontal, with sides that go up, just inside the bottom edge of the air cleaner cover, with the same hole/tube setup that's in the heat shield), and then connect the two with a short piece of insulated flexible metal tubing.

And thinking back, this is the kind of setup they did in cars back in the 70's and earlier, when they had carbs. They had a heat shield over an exhaust manifold, with a short tube, and a short tube on the air cleaner housing with a valve that opened when it was cold out, with the insulated tube connecting them, so the carb would draw air from over the exhaust manifold in cold weather.
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GM called that setup the "Thermac Air Cleaner"..many of the GM vehicles I had suffered from carb icing in damp or foggy weather when it was 50 degrees or less outside without the stock air cleaner as you described all intact,hooked up and working properly..

The first 15 minutes of driving was dangerous without that "hot air" air cleaner---after a cold start would be plagued with stalling every time I let off the gas,stopped at a red light,and a few times I had the carb not want to return to idle after the throttle butterflies got iced up enough to stick open..:eek:..
I ended up putting the stock air cleaner back on,one truck I had to rig the exhaust heat riser to stay closed and send exhaust heat up under the carb thru the cast in passages in the intake manifold to keep the Edelbrock carb from frosting up on cold damp or foggy days..however,I never had cold starting troubles,the engines always fired right up--it was during the warm up period I had all the drive-ability issues..

Many snowblowers have a metal "box" around the muffler and carb to keep sufficient heat in the carb to prevent can rig up something similar probably..but I wouldn't expect it to improve cold starting any,just keep it from frosting up after its running..
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Thanks for that catalog. I found something like it, but yours has better illustrations of the different things. But, there's no anti-freeze kit for my engine, and the cost of converting my engine to have a different intake, then add the anti-freeze kit for that intake, I might as well buy a brand new engine...

I'll give my air heater setup a shot next winter, maybe also make a hood for the motor to let it retain a bit more heat as well, and if it doesn't work, I'll probably go for repowering it, as I really could use it be dead-nuts reliable to use it. I've got an Kaw FR651V that I might be able to use instead...
Have you considered using a DC powered 'defroster' available from HF or Princess/Canadian Tire/??(I am not a Canadian)
I have one that plugs into the cigar lighter or power outlet. If you blanketed your engine, and rigged the defroster to sit within the enclosed area, plug it in when traveling to the sites where you'll need to run, and see if it helps. They are not expensive, and I think in the wattage range where they could help in not much time.
If you can keep the surrounding air from being changed, it will warm up, but if there are currents blowing in fresh cold air, it won't help. I bought one for my older vehicle with the leaking heater core that requires removing the dashboard and evacuating the HVAC to replace. Have not used it yet...
I had one of those 12V "heaters" that plug in the lighter socket--a complete joke,it put out 150W,and you'd probably get more "heat" off a headlamp bulb!..
It took a good 10 minutes for it to melt a 6" hole in the frost on the inside of my windshield..(I should have tried a 6014 headlamp bulb and see if that worked better & faster)..
I actually did look in CanadianTire for a defroster like what you describe, couldn't find one. A quick search on Princess Auto s website shows they have two (150W and 200W). Doesn't sound like much vs home heaters, but they are drawing at least 12.5A and 17A via the cigarette light... From a bit of googling, even drawing 17A from the lighter socket would blow the fuse for it for some vehicles.

And while it may take awhile for them to defrost part of a windshield, I just need to raise the temp of a fairly small part, the carb, 10-15C or so (get it from -25 or -30C to -15C), and I can enclose the area to retain the generated heat in that area (vs the inside of the car, where the heat dissipates over the whole interior of the car).
Id be more comfortable with a light bulb myself.
Just to follow up, I just (almost) finished making a hot-air intake for my CV22S. Originally, I was going to use the original plastic cover for the air cleaning, and fashion a plate underneath/behind it to prevent most air from going into the air cleaning, with a port to connect a hose to the heat shield of the muffler. Upon further reflection, it would be pretty complicated to that, so it's pretty sealed from outside air, while not interfering with the various carb controls.

Instead, I came up with just making a whole new air cleaner housing, with a port on the side of it to connect to the heat shield:
Auto part Engine Vehicle

I still need to make a cover plate for the end of the heat shield, so the air is forced to flow over the muffer, and I've got some thin stick-on cork board that I will put on some of the joints of the air cleaner housing so it's fully sealed, then I'll test it to see if it actually does work as I want (using an IR gun to see if the air cleaner housing gets any warmer when the engine runs for awhile).

If it works, great, if not, I'll try making the heat shield be closer to the muffler (now it's spaced about 1/2" from the muffler) and then test again.

Once it works (it kind of has to), I'll go for making it look a little nicer and paint it.
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I was gonna say you don't need a LOT of heat to keep things from icing up, but then realized you are up north... waaaayyyy above the Mason-Dixon line, and the 54-40 line also for history buffs. You do get some real cold. Down here, we have gotten into the 20's, don't think teens, and it was really noticed by all.
That said, what you made looks really good. You could cover the end, and even wrap a piece across the bottom opening( screw on a 'flap') that would make the incoming air have to proceed from the opposite end, along the muffler, and finally get to the 'front' and go up the squeezy aluminum tube to the air cleaner. It would make for longer 'contact' time if the air had to travel alongside the muffler or exhaust pipe before heading up. Just a thought if you find you need more heat in addition to that from closing off the 'front' opening. They don't have to be real 'airtight', just enough to get kinda close.
And to follow up on how well it works, it was just below freezing outside, and after using it for 5 minutes or longer, the main air filter housing gets just on the edge of being too hot to touch with my hand, so I would say it works a little too well.

I think I'll go back to the junkyard and get the nozzle off the air cleaner I got the flexible tube from, as I believe it has a temperature-control valve in it, and I'll put that on to regulate the intake temp to be a little cooler.
If you find the temperature operated flap valve won't work, you could try a manually operated 'damper'. The damper could be allowed to blend in cooler air, say on the tube leading up from the muffler. I think given the temperatures you will encounter sort of make it difficult to have an automatic adjustment work well. I have only seen to methods of controlling(somewhat) the incoming air. One used a bulb that expanded/contracted and one end moved a rod that in turn moved a flap to open/close access to are heated by the exhaust manifold 'stove'. The other used a vacuum valve that opened/closed to release/apply vacuum to a servo that again opened/closed a flap.
I think manual would be more likely to function as desired, but best luck on getting one to work.
Here is a place to get the Kohler CV22 service manual:


I have heard that most hard starting problems with these engines were fixed by adjustment of the valves back to original specs. Just a thought.
The engine starts and runs fine in warmer weather without any of this work, when it's -5C or higher. And even with ice forming in the input of the carb, if I remember to turn on the choke when I turn off the engine, it readily started up last year at -20C and a little below that. However, it gets down to -35C (give or take 5) here, so that's why I'm doing these mods.

And it has hydraulic lifters, so there is no manual valve adjustment to do...
Well, still no go trying to start it at -27C today, but once it was in my unheated garage (generally warmer by at least a few degree's than the outside), it did start up.
While I thought I could smell gas when trying to start it, I can't be certain about that. It wouldn't spin as fast as when it was warmer out, and didn't go any better with a battery booster pack on it, but there didn't seem to be any puffs of smoke out the exhaust, like there was when I started it in my garage.

I'll try replacing the carb when I have time (I have a new one, it wasn't that much more than the 2 separate gasket/rebuild kits for the carb) and see if it's any better.
Have you tried spraying carb cleaner into air intake to help it. I had to that on my briggs v twin last week as it was sitting outside and a generator. I've just ordered some plastic plugs so I can drill holes in air cleanercovers and insert the plug which I can pop to use the carb cleaner instead of having to remove the covers.
Have you tried spraying carb cleaner into air intake to help it. I had to that on my briggs v twin last week as it was sitting outside and a generator. I've just ordered some plastic plugs so I can drill holes in air cleanercovers and insert the plug which I can pop to use the carb cleaner instead of having to remove the covers.
Thanks for reminding me of this. I've got several cans of starter-spray, and used it last year to help get the engine started, and have a reminder that I haven't gotten around to, to add a port for spraying into instead of removing the air cleaner cover.

Tomorrow it should still be cold enough to not be able to start on it's own, if it's sitting outside. I'll go for periodically starting it, beginning in my garage, as there are several places I really want to use it, but after that, I'll let it sit and test how the starter spray works (it goes up to a balmy high of -26C).

I was also considering getting a small 12V heater/fan that I could point at the carb for a couple minutes to give it a little heat before starting it.
I assume that you are running synthetic oil in it? I think that it makes a difference in how fast engine turn over.
Yeah, I have synthetic oil in all my equipment, and the Kohler has 5W30 in it for the winter, switches to 10W30 in the summer.
...and after using it today for maybe 45 minutes straight or so, I need to either get battery-heated mitts, or figure out how to heat the control bars, as now they are just plain metal, and they just suck the heat out of my fingers, even with mitts over leather gloves.
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