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Hard Starting Without Primer

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Daniel.Snow(at)wancdf.com
Guest

Posted: Wed Apr 11, 2007 4:15 am Post subject: Hard Starting Without Primer

Based on the experience of others, I didn't install a primer on my new

Superior XP O-320 engine.  I use the mixture control to kill the engine,

so I understand fuel has to get back to the jets before it will run.

However, I'm having to crank for roughly 20 seconds, let the starter

cool, then crank again for nearly 20 seconds before it will start.  My

start sequence is;



Master on

Fuel pump on for at least 10 seconds

Throttle 1/4 open

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Stop cranking and let starter cool for 2 minutes

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Start playing with throttle to find the "sweet spot"

Starts rough until I find the "sweet spot"

Idles smoothly and runs up fine after warm



For those of you who don't use a primer, do you have any suggestions?  I

don't know if I'm giving it too much fuel or not enough.  I don't smell

gas at the air inlet, so I don't think I'm flooding it, but I'm afraid

to pump too much at the beginning.  Do I need to just let the boost pump

run for a while with the throttle at 1/4 open to get fuel to the jets,

or is that only going to work when the engine is cranking over?



I just remembered, it restarts within a couple of revolutions when I

shut it down using the mixture control, so fuel should be reaching the

jets fairly quickly on a cold start.



Thanks,



Daniel Snow

RV-9A, 1 week to SnF, 2 weeks to inspection

dale1rv6(at)comcast.net
Guest

Posted: Wed Apr 11, 2007 4:53 am Post subject: Hard Starting Without Primer

Try:

Master on

Mixture rich

Fuel pump on

Pump throttle one full stroke

Without delay; close throttle, then open 1/8 inch, crank 5 seconds, if no

start repeat throttle pump, open throttle only 1/8 inch again and crank 10

seconds.

If it does not start after 20 seconds something is wrong

After start lean mixture as much as possible while keeping engine running

smooth



After 20 years and 3,000 hrs on carb Lycoming engines I have never had to

pump while cranking.



Best of luck,

Dale



--

sheldonb(at)frontiernet.n
Guest

Posted: Wed Apr 11, 2007 4:53 am Post subject: Hard Starting Without Primer

Daniel,

I had the same kind of start problem (no primer system) early on when first 

learning my plane... 0-360

COLD STARTS: ( cold start = 1st start for the day).. Mixture rich, pump 

throttle 3 times and leave at 1/4 open, engage starter... fires right up...

HOT STARTS: Do not push or touch throttle, leave closed (pulled back).. 

leave mixture in cut off.. start cranking... slowly push mixture in.. when 

engine likes it, it will start... give some throttle to keep it running...

Works every time..

Sheldon RV6A 450 hours 0-360 FP



---

n616tb(at)btsapps.com
Guest

Posted: Wed Apr 11, 2007 6:01 am Post subject: Hard Starting Without Primer

Daniel,



I have an 0-360A1A and I couldn't start mine easily without the primer.  I

know I have heard others doing it, but I can't get mine started reasonably

without using it.  Thankfully I installed it.  Also I think you don't want

to pump the throttle unless you are cranking simultaneously.  If it is an

updraft carb, then fuel can just run out into the airbox, down the drain

hole into the cowl and well, you get the point.  Why not just install a

primer?



Tim



[quote] --

sbuc(at)hiwaay.net
Guest

Posted: Wed Apr 11, 2007 6:38 am Post subject: Hard Starting Without Primer

Daniel,



I've been flying my primerless O-320 for over seven years. I think if 

you will pull the throttle nearly closed instead of 1/4 open you will 

enjoy good starts. With my engine, it is turn on fuel pump until 

pressure is established then pump off, one or two full strokes of the 

throttle depending on how cold the ambient air, pull the throttle 

lightly closed, hit the starter button, and the engine will start within 

2-5 blades (lightweight starter, two Slick mags). Hot starts are the 

same except no fuel pump or stroking of the throttle.



The nearly closed throttle creates more vacuum in the carb and pulls the 

rich mixture into the engine better than having the throttle 1/4 open. 

If your carb idle mixture screw is set correctly, the engine should 

start fine on nearly closed throttle.



Sam Buchanan



==================================



Snow, Daniel A. wrote:

 	  Quote: 	
		   

 

 Based on the experience of others, I didn't install a primer on my new

 Superior XP O-320 engine.  I use the mixture control to kill the engine,

 so I understand fuel has to get back to the jets before it will run.

 However, I'm having to crank for roughly 20 seconds, let the starter

 cool, then crank again for nearly 20 seconds before it will start.  My

 start sequence is;

 

 Master on

 Fuel pump on for at least 10 seconds

 Throttle 1/4 open

 Crank for 5 seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Stop cranking and let starter cool for 2 minutes

 Crank for 5 seconds

 Pump throttle one time and hold at 1/4 open

 Start playing with throttle to find the "sweet spot"

 Starts rough until I find the "sweet spot"

 Idles smoothly and runs up fine after warm

 

 For those of you who don't use a primer, do you have any suggestions?  I

 don't know if I'm giving it too much fuel or not enough.  I don't smell

 gas at the air inlet, so I don't think I'm flooding it, but I'm afraid

 to pump too much at the beginning.  Do I need to just let the boost pump

 run for a while with the throttle at 1/4 open to get fuel to the jets,

 or is that only going to work when the engine is cranking over?

 

 I just remembered, it restarts within a couple of revolutions when I

 shut it down using the mixture control, so fuel should be reaching the

 jets fairly quickly on a cold start.

 

 Thanks,

 

 Daniel Snow

 RV-9A, 1 week to SnF, 2 weeks to inspection

n801bh(at)netzero.com
Guest

Posted: Wed Apr 11, 2007 6:50 am Post subject: Hard Starting Without Primer

The carb is an updraft one and it is located on the bottom of the motor. You need intake velocity to carry the mixture up and into the cylinders. Just as you get the motor turning over with the starter pump the throttle several times, that will spray the fuel from the accelerator pump jet into the incoming airstream and  then it will be carried to the cylinders.Just pumping the throttle while the motor is not spinning will cause the fuel to puddle into the airbox,,, Just my two cents worth.. do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "Snow, Daniel A." <Daniel.Snow(at)wancdf.com> wrote:

--> RV-List message posted by: "Snow, Daniel A." <Daniel.Snow(at)wancdf.com>



Based on the experience of others, I didn't install a primer on my new

Superior XP O-320 engine.  I use the mixture control to kill the engine,

so I understand fuel has to get back to the jets before it will run.

However, I'm having to crank for roughly 20 seconds, let the starter

cool, then crank again for nearly 20 seconds before it will start.  My

start sequence is;



Master on

Fuel pump on for at least 10 seconds

Throttle 1/4 open

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Stop cranking and let starter cool for 2 minutes

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Start playing with throttle to find the "sweet spot"

Starts rough until I find the "sweet spot"

Idles smoothly and runs up fine after warm



For those of you who don't use a primer, do you have any suggestions?  I

don't know if I'm giving it too much fuel or not enough.  I don't smell

gas at the air inlet, so I don't think I'm flooding it, but I'm afraid

to pump too much at the beginning.  Do I need to just let the boost pump

run for a while with the throttle at 1/4 open to get fuel to the jets,

or is that only going to work when the engine is cranking over?



I just remembered, it restarts within a couple of revolutions when I

shut it down using the mixture control, so fuel should be reaching the

jets fairly quickly on a cold start.



Thanks,



Daniel Snow

RV-9A, 1 week to SnF, 2 weeks to inspectio========================        - The RV-List&the many List utilities such as the S================================================        - NEW MATRONIC now also available via the Web Forum====================================   [quote][b]

jim jewell

Joined: 09 Jan 2006
Posts: 82
Location: Kelowna B.C. Canada

Posted: Wed Apr 11, 2007 8:34 am Post subject: Hard Starting Without Primer

Ben,

  

 I think your two cents worth are well worth the  investment. If I may I would like to add my own two cents  worth;

  

 The fuel "puddle in the airbox" and surrounding  area then becomes subject to potential fire hazard conditions due to subsequent  engine backfire.

 It has happened to others in the past.

 Reduction of fire hazard and easier starting are  two of the main reasons for the addition of primmer systems.

 During starting raw fuel is best introduced  into the intake ports immediately ahead of the intake valve (carbureted  systems) or in the cylinders (fuel injected systems).

 Raw fuel in the airbox is ill  advised, hard on the environment, at least partially wasted, and has  been known to waste aircraft in the past.

  

 OK, maybe three cents worth, {[

  

 Jim in Kelowna  RV6A !.5 hr. 

 [quote]   ---

_________________
"I never make mistreaks"

dale1rv6(at)comcast.net
Guest

Posted: Wed Apr 11, 2007 10:05 am Post subject: Hard Starting Without Primer

Two things to consider:

If the result of one pump of throttle is liquid and not spray, your cranking

engine will not pull the liquid against gravity.



2nd; my method is to pump once and crank immediately before it condenses.

This allows me to set the throttle to correct position (nearly closed eg 1/8

inch from closed) for cold start.



I agree that multiple pumps will cause excess liquid fuel and is a fire

hazard, even while cranking. Multiple pumps is similar to working with

hammers and pliers when you need wrenches. 



Dale



--

randy(at)romeolima.com
Guest

Posted: Wed Apr 11, 2007 1:59 pm Post subject: Hard Starting Without Primer

If you pump the throttle without the engine turning over to suck the fuel 

from the accelerator pump in you are risking an intake fire. I've actually 

seen it happen right before my eyes. Therefore I would strongly recommend 

you pump the throttle AFTER you engage the starter.



Also, IIRC, while the MA4-5 carburetor used on virtually all carbureted 

O-360s has an accelerator I seem to remember that many of the models for the 

O-320 do not. Get the exact model number of your carburetor and do some 

reasearch on it to determine whether it has an accelerator pump or not. If 

it doesn't then pumping won't do any good. Once you get the model number you 

can always call Precision Airmotive for confirmation... 

http://www.precisionairmotive.com/



Randy Lervold

---

kboatright1(at)comcast.ne
Guest

Posted: Wed Apr 11, 2007 2:07 pm Post subject: Hard Starting Without Primer

My experience is similar to what Sam Buchanan posted.



My technique is to turn the fuel pump on, mixture rich, one pump of the 

throttle, then wait for 10-20 seconds (in my case, that's about how long it 

takes to fasten all of the belts).  Then, throttle barely cracked and hit 

the starter.  The engine starts right up.



KB

---

bobbyhester(at)charter.ne
Guest

Posted: Wed Apr 11, 2007 2:40 pm Post subject: Hard Starting Without Primer

I only have 22 hrs on my XP-O360 and I start it just Like Ben says below and it starts just fine!

  	  Quote: 	
		  Surfing the web from Hopkinsville, KY

My RV7A website: http://webpages.charter.net/bobbyhester/MyFlyingRV7A.htm 	
 

 

 n801bh(at)netzero.com (n801bh(at)netzero.com) wrote: [quote]The carb is an updraft one and it is located on the bottom of the motor. You need intake velocity to carry the mixture up and into the cylinders. Just as you get the motor turning over with the starter pump the throttle several times, that will spray the fuel from the accelerator pump jet into the incoming airstream and  then it will be carried to the cylinders.Just pumping the throttle while the motor is not spinning will cause the fuel to puddle into the airbox,,, Just my two cents worth.. do not archive

   

   

 Ben Haas

 N801BH

 www.haaspowerair.com

   

 -- "Snow, Daniel A." <Daniel.Snow(at)wancdf.com> (Daniel.Snow(at)wancdf.com) wrote:

 --> RV-List message posted by: "Snow, Daniel A." <Daniel.Snow(at)wancdf.com> (Daniel.Snow(at)wancdf.com)

   

 Based on the experience of others, I didn't install a primer on my new

 Superior XP O-320 engine.  I use the mixture control to kill the engine,

 so I understand fuel has to get back to the jets before it will run.

 However, I'm having to crank for roughly 20 seconds, let the starter

 cool, then crank again for nearly 20 seconds before it will start.  My

 start sequence is;

   

 Master on

 Fuel pump on for at least 10 seconds

 Throttle 1/4 open

 Crank for 5 seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Pump throttle one time and hold at 1/4 open

 Continue cranking for 5 more seconds

 Stop cranking and let starter cool for 2 minutes

 Crank for 5 seconds

 Pump throttle one time and hold at 1/4 open

 Start playing with throttle to find the "sweet spot"

 Starts rough until I find the "sweet spot"

 Idles smoothly and runs up fine after warm

   

 For those of you who don't use a primer, do you have any suggestions?  I

 don't know if I'm giving it too much fuel or not enough.  I don't smell

 gas at the air inlet, so I don't think I'm flooding it, but I'm afraid

 to pump too much at the beginning.  Do I need to just let the boost pump

 run for a while with the throttle at 1/4 open to get fuel to the jets,

 or is that only going to work when the engine is cranking over?

   

 I just remembered, it restarts within a couple of revolutions when I

 shut it down using the mixture control, so fuel should be reaching the

 jets fairly quickly on a cold start.

   

 Thanks,

   

 Daniel Snow

 RV-9A, 1 week to SnF, 2 weeks to inspectio========================        - The RV-List&the many List utilities such as the S================================================        - NEW MATRONIC now also available via the Web Forum====================================    	  Quote: 	
		  





  	
 [b]

PittsS1(at)aol.com
Guest

Posted: Wed Apr 11, 2007 2:47 pm Post subject: Hard Starting Without Primer

starting ... you guys sure make it difficult



See what's free at AOL.com. 

  [quote][b]

dbris200(at)sbcglobal.net
Guest

Posted: Wed Apr 11, 2007 4:58 pm Post subject: Hard Starting Without Primer

If you crank the engine with the throttle partially open, you'll draw 

very little fuel into the cylinders. If the throttle is completely 

closed it will pull fuel through the idle circuit and make starting a 

lot easier. I learned this early on when I started flying a hand propped 

Continental. You had to pull the prop through with the throttle closed 

until it sounded "squishy" then crack the throttle and it started on the 

first blade. If you have to pump the throttle, you're doing something wrong.



Dave



Also, a minor point, the primer and injectors both add the fuel before 

the valve, not directly into the cylinder.



 	  Quote: 	
		   During starting raw fuel is best introduced into the intake ports 

 immediately ahead of the intake valve (carbureted systems) or in the 

 cylinders (fuel injected systems).

 *

 *

jim jewell

Joined: 09 Jan 2006
Posts: 82
Location: Kelowna B.C. Canada

Posted: Wed Apr 11, 2007 6:46 pm Post subject: Hard Starting Without Primer

Hi Dave,



You are right , I stand corrected.



Jim in Kelowna



---

_________________
"I never make mistreaks"

tn3639(at)hotmail.com
Guest

Posted: Thu Apr 12, 2007 3:50 am Post subject: Hard Starting Without Primer

I have basically the same setup and all I do is pump the throttle once or 

twice depending on the temperature and it fires off within one or two 

blades. You may need to check your ignition system. The local spam can 

rental was having the same problem and it was traced to a bad mag.



Generally if it is getting fuel, air and spark something is going to happen 

pretty quick. Not to mention that you are damaging your starter with all 

that cranking...



Hope this helps and let us know what happens.



Scott



Based on the experience of others, I didn't install a primer on my new

Superior XP O-320 engine.  I use the mixture control to kill the engine,

so I understand fuel has to get back to the jets before it will run.

However, I'm having to crank for roughly 20 seconds, let the starter

cool, then crank again for nearly 20 seconds before it will start.  My

start sequence is;



Master on

Fuel pump on for at least 10 seconds

Throttle 1/4 open

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Pump throttle one time and hold at 1/4 open

Continue cranking for 5 more seconds

Stop cranking and let starter cool for 2 minutes

Crank for 5 seconds

Pump throttle one time and hold at 1/4 open

Start playing with throttle to find the "sweet spot"

Starts rough until I find the "sweet spot"

Idles smoothly and runs up fine after warm



For those of you who don't use a primer, do you have any suggestions?  I

don't know if I'm giving it too much fuel or not enough.  I don't smell

gas at the air inlet, so I don't think I'm flooding it, but I'm afraid

to pump too much at the beginning.  Do I need to just let the boost pump

run for a while with the throttle at 1/4 open to get fuel to the jets,

or is that only going to work when the engine is cranking over?



I just remembered, it restarts within a couple of revolutions when I

shut it down using the mixture control, so fuel should be reaching the

jets fairly quickly on a cold start.



Thanks,



Daniel Snow

RV-9A, 1 week to SnF, 2 weeks to inspectio========================        - 

The RV-List&the many List utilities such as the S=======================     

    - NEW MATRONIC now also available via the Web 

Forum====================================

href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List

href="http://forums.matronics.com">http://forums.matronics.com



_________________________________________________________________

Mortgage rates near historic lows. Refinance $200,000 loan for as low as 

$771/month* 

https://www2.nextag.com/goto.jsp?product=100000035&url=%2fst.jsp&tm=y&search=mortgage_text_links_88_h27f8&disc=y&vers=689&s=4056&p=5117

Daniel.Snow(at)wancdf.com
Guest

Posted: Thu Apr 12, 2007 4:24 am Post subject: Hard Starting Without Primer

As I've posted before, my Superior XP O-320 has the same MA4-5 used on

the O-360's.  Someone pointed out that they could feel when the

accelerator pump was pumping fuel, however the MA4-5 has a spring

connection to the pump lever that causes the pump to move at a

semi-constant speed regardless of how quickly you pump the throttle.



Thanks for all the suggestions guys.  Last night I pumped one time and

closed the throttle, followed immediately by cranking.  It started in

2-3 blades.  The next test is to not pump before cranking and see if the

idle circuit is enough to start the engine in a couple of blades.



Daniel Snow

 	  Quote: 	
		  Also, IIRC, while the MA4-5 carburetor used on virtually all carbureted


	


 	  Quote: 	
		  O-360s has an accelerator I seem to remember that many of the models

for the 
	


 	  Quote: 	
		  O-320 do not. Get the exact model number of your carburetor and do some


	


 	  Quote: 	
		  reasearch on it to determine whether it has an accelerator pump or not.

If 
	


 	  Quote: 	
		  it doesn't then pumping won't do any good. Once you get the model

number you 
	


 	  Quote: 	
		  can always call Precision Airmotive for confirmation...

dale1rv6(at)comcast.net
Guest

Posted: Thu Apr 12, 2007 4:41 am Post subject: Hard Starting Without Primer

Glad to hear the good news, great progress!



Do not archive



--

dbris200(at)sbcglobal.net
Guest

Posted: Thu Apr 12, 2007 7:01 am Post subject: Hard Starting Without Primer

This is a good point. My AFP injected O360A1D started perfectly for 

several years even though I had installed the wrong Shower of Sparks 

unit and it wasn't working at all, meaning that it was starting with NO 

spark retard because the SkyTec starter cranked it so fast that it 

didn't matter. Then when the battery started to get weak it got very 

hard to start. Modifying the SOS solved the problem.

So, check the ignition system, be sure it's starting on the correct mag 

and that the impulse is working.



Dave

 	  Quote: 	
		   You may need to check your ignition system. The local spam can rental 

 was having the same problem and it was traced to a bad mag.

johnd(at)wlcwyo.com
Guest

Posted: Thu Apr 12, 2007 7:55 am Post subject: Hard Starting Without Primer

I agree with not being to aggressive about pumping the throttle when

starting.

The exception to this is when you are trying to start a very cold engine

( 0 deg or colder). I had problems starting my engine while in Rochester

MN about 4 years ago. The outside temp was -10 Deg., the plane had been

in a hanger at about 15 deg. The engine just would not start with normal

priming and a pump or two of the throttle. 

One old boy told me to pump the throttle vigoursly as I cranked the

engine. I probably pumped the throttle 10 times, but the engine did

catch and began to run normally.

Just a thought.



John L. Danielson

--

n801bh(at)netzero.com
Guest

Posted: Thu Apr 12, 2007 4:43 pm Post subject: Hard Starting Without Primer

Your point is well taken. Here where I live in Jackson Hole Wy a 0 degree day is about half the year. . My theory was to pump the throttle while cranking the motor. As soon as it starts just use enough throttle to keep it running. On a cold day it will take several shots of fuel through the accelerator pump, of course if it is warmer then the motor will light off on the first pump, or maybe even before. !!!!     YMMV.............. 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "John Danielson" <johnd(at)wlcwyo.com> wrote:

--> RV-List message posted by: "John Danielson" <johnd(at)wlcwyo.com>



I agree with not being to aggressive about pumping the throttle when

starting.

The exception to this is when you are trying to start a very cold engine

( 0 deg or colder). I had problems starting my engine while in Rochester

MN about 4 years ago. The outside temp was -10 Deg., the plane had been

in a hanger at about 15 deg. The engine just would not start with normal

priming and a pump or two of the throttle. 

One old boy told me to pump the throttle vigoursly as I cranked the

engine. I probably pumped the throttle 10 times, but the engine did

catch and began to run normally.

Just a thought.



John L. Danielson

--

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