Cold Weather Starting

[BobRip]

The mighty Kohler failed to start this morning at -19F even with a 2 second blast of starting fluid. I tried it twice, cranking for no more than 8-10 seconds. No POP. It cranked REAL slow. So, I will put a 50A battery booster on it when I get home. If that doesn't get it, I will pre-heat. I didn't need it, but wanted to see if it would start. Had I needed it, I would have gotten out of be earlier.

This is the coldest it has been since I bought it in 2001. I actually got too warm brushing off the car this morning, as I overdressed.

So the Kohler is also affected by the cold. Maybe is has a little stronger starter, but it still has limits. All machines need that hydraulic pump disconnect.

 

[duane]

Something like a mechanical PTO clutch on a wheelhorse tractor or similiar. A lever that engages and disengages the tram pump. In the summer you could leave it engaged all the time.

 

[RegL]

Yeah. The roof started booming last night. It scared the kids. I hadn't heard that for 20 years. Took me a while to remember what it was. You ever been out on a lake and had the ice boom on you? Pretty weird stuff. But it used to be like that all the time in the winter when I was younger. I kind of miss it. The colder the better, in my book.

Haven't been ice fishing since I quit drinking. I remember the ice booming though.

 

[SnowRidge]

A clutch between the engine and the pumps would be nice, but......

It would probably require a longer tub. Those clutches take up space. Like anything else, it would increase costs, and PTs would have to be priced higher.

If I needed to operate my PT-425 in real cold weather, I would try one of these suspended in the tub with a thermal blanket over the machine.

 

[MossRoad]

Roof booming? Are you sure a bunch or rockers aren't practicing in your attic?

There's no rockers up there, that's where we keep the victims.

The roof goes BOOM! as it contracts and expands. I really remember it a lot from when I was a kid. Kind of brought back fond memories.

 

[MossRoad]

Well, it turns out it was just flooded!

I noticed fuel spitting up out of the carb and exhaust. So, I shut off the fuel completely and opened the choke fully and cranked it for 10 seconds and then waited a minute, repeating until it stopped spitting fuel out of the exhaust and carb. Then I set the choke to full with throttle off and cranked it. While cranking, I slowly increased the throttle and it fired right up without any starting fluid. The temp was -7F.

So, I need to revise my cold weather starting procedure to full choke, NO fuel, and increase the fuel slowly as I crank until it starts. I may also change the plugs, as they are the originals from 2001 with 350 hrs on them.

 

[ldabe]

My PT 422 with Robin eng. has been starting up fairly well, since, I keep it in the garage (attached, insulated, but not heated) and a trickle charge connected (per MR).

I place the throttle in high, full choke, crank for about 10 seconds (never starts on the first try).
Then I wait for about 25 seconds and crank again. But it still has to be held in the "start/crank" position for to long (10-20 seconds) as far as I am concerned, before it will stay running.

Today, I did some snow removal around the house and then the driveway (gravel) approx. 1500' long. I have a concrete apron about 20'X30' from the road entering into the drive. It gets full of ice and snow, so I went to scrap it with the bucket, and the motor died (after running well for about 25-35 minutes)!
It sputtered just a moment before this.
I waited a couple of seconds, then cranked it over. It ran ok for about 2 minutes, then began to sputter again.
I was afraid I would be left stranded out by the road, so I headed back to the house (Thanking God it started again, and praying it would make it back to the house),
but to keep it running I had to keep the throttle set on high, and keep adjusting the choke back and forth.

In the garage, (without moving of course) if I kept the choke full, and the throttle half way, it ran no problem. But if I throttle up, it would start the sputter. If I openned the choke it would start to sputter.
("sputter" - don't know if that is the correct mechanical term?)

Has anyone had this happen or similar?
Does anyone have any suggestions to what the problem may be?

I have approx. 1/2 to 3/4 of gas in the tank, and the gas might be a week old, if that.

If I have said it a thousand times, let me say it a thousand and one: "You can't beat the PT when it is running well, but, it is just a massive paper weight when it is not!"

Again, I really don't have alot against PT (except for a few stupid engineering layouts).

But, the "Robin Engine", it has been this machines BIGGEST downfall!

I will never have another Robin Engine after this one.
It is like walking on "eggshells" all the time, you never know when it is going to break down. It just doesn't give you that reliable feeling.

I have never, let me repeat that, NEVER, had as much trouble (or a feeling of unreliability) with any other engine in my life! And I am half of a century old!

Hope someone knows what the problem with the "sputter" is, or has some good suggestions.

Thanks in advance, and sorry for such a long post.

 

[duane]

Idabe,

Certainly sounds like a fuel issue. The new gas has a 10% ethanol mixture which really attracts water. An analogy is that 10 gallons of fuel has one gallon of ethanol, the one gallon of ethanol is equal to approx 12 bottles of Heet or similiar gas anti-freeze. Too much water, and the ethanol will separate from the gas in a heavier mixture and cause running problems.

Other than that, it could be anything from the gas line, fuel filter, fuel pump, anti diesel solenoid or pluggage in the carb. Give everything a good visual inspection. Good luck and let us know what you find.

 

[SnowRidge]

I may also change the plugs, as they are the originals from 2001 with 350 hrs on them.

Our Kohlers call for a special plug which nobody seems to stock, Champion Platinum 3071. I had to get mine from Napa. It took them a day or two.

Watch out for substitutions. Some brands list a non platinum plug as a direct substitute for the 3071. As a test, see if the chart lists the same plug as a sub for both the Champ 3071 and RC12YC. If it does, it is likely to be only a true substitute for the plain RC12YC.

 

[Carpenter]

I found that my Kohler 425 starts much better at low temps if I keep the fuel dosed with Sta-Bil fuel stabilizer. It doesn't seem to matter how fresh the fuel is it just starts easier with the Sta-Bil.

 

[BobRip]

Idabe,

Certainly sounds like a fuel issue. The new gas has a 10% ethanol mixture which really attracts water. An analogy is that 10 gallons of fuel has one gallon of ethanol, the one gallon of ethanol is equal to approx 12 bottles of Heet or similiar gas anti-freeze. Too much water, and the ethanol will separate from the gas in a heavier mixture and cause running problems.

Other than that, it could be anything from the gas line, fuel filter, fuel pump, anti diesel solenoid or pluggage in the carb. Give everything a good visual inspection. Good luck and let us know what you find.

Definitely a fuel issue. Check the outlet on the bottom of the tank. That can get clogged with trash. Also it could be the fuel pump. Should have about 1 PSI or greater output. Also change the fuel filter.

 

[MossRoad]

Our Kohlers call for a special plug which nobody seems to stock, Champion Platinum 3071. I had to get mine from Napa. It took them a day or two.

Watch out for substitutions. Some brands list a non platinum plug as a direct substitute for the 3071. As a test, see if the chart lists the same plug as a sub for both the Champ 3071 and RC12YC. If it does, it is likely to be only a true substitute for the plain RC12YC.

Thanks for the tip. A couple years ago I bought a air filter/spark plug all-in-one kit for the air cleaner. I never used the plugs. I dug them out of my box O' parts today. They are Champion RC12YC.

 

[SnowRidge]

The RC12YC plugs are used in some of the Kohlers, but I'm not sure which ones. The platinum plugs are spec'd for the Command Pro models.

 

[MossRoad]

The RC12YC plugs are used in some of the Kohlers, but I'm not sure which ones. The platinum plugs are spec'd for the Command Pro models.

I know it is a Kohler Command, but I'm not sure if it is a Pro. I'll have to look.

 

[KentT]

I know it is a Kohler Command, but I'm not sure if it is a Pro. I'll have to look.

Not sure, but I think the only difference in the CH's is that the Command Pro had an external oil cooler down near the oil filter.

 

[PILOON]

Could the problem be carb iceing?

Carbs, as you know, have a venturi body.
In certain conditions the air rushing in the venturi will freeze if moist enough thus throttling or choking the venturi.
Warm air to the intake is the usual cure. Some carb equipped cars had 'heat riser tubes' to preheat the carb intake air.
Also cold damp air can cause the spark plug gap to frost over thus shorting the plug.
In old dew line days the pilots would keep engine plugs with them in the sleeping bag overnite.

I recall times when my old VW beetle would loose power from carb icing.

 

[MossRoad]

Could the problem be carb iceing?

Carbs, as you know, have a venturi body.
In certain conditions the air rushing in the venturi will freeze if moist enough thus throttling or choking the venturi.
Warm air to the intake is the usual cure. Some carb equipped cars had 'heat riser tubes' to preheat the carb intake air.
Also cold damp air can cause the spark plug gap to frost over thus shorting the plug.
In old dew line days the pilots would keep engine plugs with them in the sleeping bag overnite.

I recall times when my old VW beetle would loose power from carb icing.

A heat riser tube will only help once the engine is running and the exhaust manifold gets hot enough to create warm air around it. I had one on a 70 Nova. It rusted off and we never noticed a difference!

I have heard of plugs frosting over, but only on airplanes. Hmmm... those were air cooled engines. In the winter, we ALWAYS pre-heated them with the dragon (propane powered heat unit with flame proof flexible metal heat ducts) for about 10-15 minutes before starting them. Hmmmm.... my Kohler and the others' Robin engines are air cooled.... Hmmmmm...... maybe we should pre-heat?

Dang gum it!!! Why does it take so long for me to realize these things????

Red Dragon Propane Engine Preheaters


OUCH! $500.00 and up!

 

[SnowRidge]

A heat riser tube will only help once the engine is running and the exhaust manifold gets hot enough to create warm air around it. I had one on a 70 Nova. It rusted off and we never noticed a difference!

I have heard of plugs frosting over, but only on airplanes. Hmmm... those were air cooled engines. In the winter, we ALWAYS pre-heated them with the dragon (propane powered heat unit with flame proof flexible metal heat ducts) for about 10-15 minutes before starting them. Hmmmm.... my Kohler and the others' Robin engines are air cooled.... Hmmmmm...... maybe we should pre-heat?

Dang gum it!!! Why does it take so long for me to realize these things????

Red Dragon Propane Engine Preheaters


OUCH! $500.00 and up!

Install this and pretend your PT has wings.

 

[cqaigy2]

My motor cycle was air cooled and it always started. I think the coldest i can remember riding it was -11 when it got to -40 just couldn't wear enough cloths to keep warm at 50+mph

 

[BobRip]

My motor cycle was air cooled and it always started. I think the coldest i can remember riding it was -11 when it got to -40 just couldn't wear enough cloths to keep warm at 50+mph

Does your motor cycle have to drive a hydraulic pump when cranking? Basically the starter motors are sized to start a cold engine with no mechanical load, although the larger starter on on my Robin engine did not seem to help. After one failure to start, I moved the machine back to the heated garage.

Moss, could you use a torpedo heater to heat the engine? Would a hair dryer on the air intake help. Has anyone tried that? Preheat the intake for a few minutes and keep it blowing while cranking. You could also preheat the fuel line and help a little more.