Cold mornings

[JG3]

Sunday morning at Monto, temp -1C.

 

My Rotax started immediately, and warmed up much quicker than others that I watched ground running for ages to try to get the temps up. This difference was due to the coolant thermostat that I have recently installed. It makes a heck of a difference to warm-up time, and keeps absolutely constant 92 degrees in flight. See the story at StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft

 

Also noted that a quad bike with booster battery was making the rounds to start Jabirus.......

 

JG

 

 

[Tomo]

Started the 2200 in Dalby sat morning - looked at the outside air temp; -1

 

First revolution that was too! Go figure...

 

 

[Vorticity]

Well, when my crew left the jab3300 started first turn and the two rotax 912s would not start :( I saw the quad bike help out two Cherokees. Rod stiff was talking to someone over at the jab display regarding the cold starting. The guy has a new jab engine and it won't start in the cold. Rod was very eager to hear about this. They have apparently been placing engines in a freezer room so as to work out any starting problems butvthey keep starting. He asked theowner if the could try out a new gizmo in his engine. Good to see some interest in continued R&D.

 

 

[Towering Cu]

Sunday morning at Monto, temp -1C.My Rotax started immediately, and warmed up much quicker than others that I watched ground running for ages to try to get the temps up. This difference was due to the coolant thermostat that I have recently installed. It makes a heck of a difference to warm-up time, and keeps absolutely constant 92 degrees in flight. See the story at StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft

G'day John,

 

I see that Evektor have had a thermostat available for the 912 Sportstar for some time. Could also be an option for other Rotax users.

 

http://www.evektor.cz/pdf/support/bulletins/EuroStar/EuroStar_Bull_010b_En.pdf

 

Mike.

 

 

[JG3]

Mike,

 

I recognize that as a Permacool brand oil thermostat. Several of us have tried them and found disappointing results. I found the Thermo-Bob coolant thermostat to be much more effective, without all those hoses and hoseclamps running hot oil.

 

JG

 

 

[Towering Cu]

I must admit that the thermostat you link to certainly looks like a far more simple and straight forward installation.

 

 

[markendee]

Howdy John,

 

Thanks for the great article on your Stolspeed website. Read it with lots of interest.

 

We at Tonny have been discussing oil thermostats lately but not too keen for most of the same reasons you mention.

 

I am particularly interested in your thoughts that engine oil temp are perhaps not as critical as we have believed.

 

We will be looking into the T Bob.

 

Thanks for posting another of your very worthwhile posts.

 

Mark D

 

 

[Yenn]

I had a lot of trouble with cold starts, and in Central Qld that is down to near zero, but after installing an extra earth lead, no more problems.

 

 

[Guest Escadrille]

G'day Yenn,

 

A couple of years ago I had a lovely Corby (sigh, I miss that little beauty..) that had an early solid lifter 2200 Jab in her. This engine was very hard to start in Toowoomba (2150'AMSL) on cold winter mornings.

 

I had some success with the English method, choke on, wind 8 blades by hand, jump in quick and start. This was not always successful... I had better success with running a hair dryer (carefully) into the cowl while I preflighted in the hangar, a quick pushout, chock and start. Away she would go..

 

BUT when I was away any where (in Winter),and she sat out over night.. no go at all until cowls were off and sat in the sun until 1000 am - really,really painful!

 

I have a new Jab hydraulic lifter 2.2 in my recently acquired Jab SP 470 and, up until this weekend,she would start first blade on the starter( with choke).!

 

However this Sunday (new field at 450'AMSL) she was reluctant to start.. after full choke spin her over wait ...spin her over ,wait.. she finally started..

 

BTW the battery is healthy..

 

How and where did you fit the other earth lead pray tell? Any other solutions ? Mebbe I better fit that solenoid that Slarti told me about...

 

 

I can't hel[p but think the fuel is not making its way up the induction tubes(vaporizing) from the Carb..

 

Andy

 

 

[Tomo]

after full choke spin her over wait ...spin her over ,wait.. she finally started...

Typical of an electrical issue. No joke!

 

BTW the battery is healthy...

You can have the best battery, but if the starter isn't getting the required current - makes not a real lot of difference. Obviously the bigger the battery, the better. But in this case I don't think that is your problem, it is getting the current to your starter - unhindered.

 

Mebbe I better fit that solenoid that Slarti told me about...

Yep, that and a good earth lead :thumb_up:

 

I can't help but think the fuel is not making its way up the induction tubes(vaporizing) from the Carb...

If it isn't spinning over at the correct speed, none of that works efficiently, it's ok after it has warmed up, but for a cold engine... One of the reasons for a choke.

 

I'm probably just repeating a lot of things, but it is one of the biggest problems we see as a mechanic.

 

Example: Perkins 6354 in an old truck, his auto ether thingo he fitted stopped working, so he wanted me to fix that. For those that know these engines would realize they certainly shouldn't need ether to start. We did a few checks, and it was his starter motor that was playing up, and not spinning fast enough/ the old style starter that draws more current than the opera house, for not much to show for it. No more need for ether!

 

Sorry... dunno if that is a help or what

 

 

[Guest Escadrille]

Ok I have a brand new lead to the starter to the Solenoid as per the Engine installation directive by Jabiru. I have read a number of times in the Forums,on the need for a "good " Earth. I do understand this BUT what specs do they mean.. I mean by "good" -no one specifies size , length grade or where this good lead is preferably attached to! Makes it hard to manufacture and attach one!

 

Or , alternatively, where is this second one attached to?

 

As a matter of fact as the Jabiru is the latest spec engine, why do I need a new solenoid at all if ( according to Vorticity) Jabiru is testin engines by putting them in the freezer(fercryinoutloud..) and then starting them fine...

 

Any one help here?

 

 

[bones]

Well, when my crew left the jab3300 started first turn and the two rotax 912s would not start :(

Usually if a 912 wont start no matter the temp, change the plugs, and the problem goeth away, i always know when my plugs are about 500hrs, it start no wanting to start on cold morning, just got back from 2 months flying anywhere from a high of 4* to -5* and the motors started straight up, mine was starting to get sluggish, so i just finished service and done the plugs.

 

 

[Guest stan kleidon]

Hi Yen, at chinchilla we got two 3300 jabs one starts good in the cold, other one doesn't we tried all that hair dryer stuff, didn't start till we put jumper jeads on. where did you add other earth lead ? i tried a a heavier solenoid pressed button nothin happened it worked on ute battery and jab battery but when using start button nothing so put jab one back on gave engine a run, and recon i'll go fishin instead.

 

 

[bushpilot]

Best trick for Jab 2200 and 3300 is to gap the plugs down to 20 thou.. We start em in 0C with no problems..

 

 

[Yenn]

I put a cable of equal size to the positive cable for the earth. Ran it from the battery dorect to the engine casing. Solved my problems, but it is getting colder here now so I am fingers crossed.

 

 

[Old Koreelah]

I modified my choke as per instructions from the late "The Bushman". Now my tiny little 120 cca battery starts my new Jab 2.2

 

 

[Guest Escadrille]

Hey Old Koreelah Can ypiu please expand on the choke mod? Is that drill out jet to 1.3 mm?

 

 

[Old Koreelah]

One mm only.

 

 

[Guest Escadrille]

Thank you , much obliged.

 

 

[bushpilot]

Hmmm - Winter has arrived and now our J230s dont like these cold mornings - even with all the recommended Jab factory mods - drilled choke jets (1.2mm), 19 thou plug gaps, earth wire and fully charged batteries. Even a 900 amp jump pack wont kick one on the 230s into life. Leave it til later in the day when air temp goes above 10 degrees and they both start just fine. Our J160 is fine all the time.

 

Anyone had recent experience with overcoming 2 degree morning starts??

 

 

[brilin_air]

If you have a jab that is a bit difficult to start in cold weather I have found that if you spin the engine with the starter and then turn on the mags it helps

 

Brian

 

 

[slartibartfast]

At the risk of repeating myself, It's the starter solenoid. Replace it with a quality one and be amazed.

 

Mine starts first turn when it's -7 degrees now.

 

Stands to reason. If you've done all the other things, and a jump pack won't turn it well enough, then the current is going somewhere else.

 

In this case, I found it to be leaking to earth at the solenoid.

 

 

[bushpilot]

At the risk of repeating myself, It's the starter solenoid. Replace it with a quality one and be amazed.Mine starts first turn when it's -7 degrees now.

Stands to reason. If you've done all the other things, and a jump pack won't turn it well enough, then the current is going somewhere else.

 

In this case, I found it to be leaking to earth at the solenoid.

SBF, What solenoid did you put in yours? And where did you get it? And what motor is it?

 

 

[slartibartfast]

SBF, What solenoid did you put in yours? And where did you get it? And what motor is it?

A Cole-Hersee like this:

 

Looking at their catalog it looks like part number 24047.

 

I got it from a regular auto electrician.

 

Motor is Jab 2200.

 

 

[mkennard]

Been talking to a few people and I'm going to try this this weekend.

 

Choke on with fuel pump. Give it a quick crank to prime and turn off choke and try and start. I have a terrible time even in Sydney to start. I think the choke just floods the engine.