starting techniques (2012)

hi guys
just canvasing starting techniques for the old commando , as ive givenit a good go but havent been succesful.
1 fuel on tickle carbs
2 half throttle no choke
3 kick away
???
i think i flooded it today as i gave the choke a bit of a work out yes ! and yess i have spark but she is on points and the gnition cables are a wee bit old
cheers
macca

Ha, its a female mechanism at base so takes a guy a while of trial and error to start their fires.
Tickling or choke should start cool, but not both unless below freezing I've found. Leave throttle closed at first, if no go then crack a bit, if no go, try WOT. If no go wait till you recover you wind and repeat above till sucess or too beat up to procede, then tract back everything that could prevent life, fuel or crap in tank to new plugs now fouling from the flooding. When mine hasn't started in a while d/t some fault like dead battery, loose float bowl, oil leaks in chambers, it seens to take forever to get a new start, but after that back to normal one or two kicks cold and one kick no tickle no throttle for rest of the day even after cooled down by a lunch break or work day interval. Might try closer plug gap, assuming timing is right, only a few degree's off has stiffed me off riding expectations.

For cold, I need to add a bit of choke as well as tickle. After riding I make sure to feel the head to see how warm it is, that tells me if I need to tickle or not. hot head, no, warm head, very little, cold head, definately.

You failed to mention the positioning of pistons just at or past TDC then giving a kick. Otherwise, at least for me, I'll come down on it and often times it just doesn't want to move. if I ease it to TDC though, I'm almsot always guaranteed a 1 or 2 kick start no matter how long it has sat, sometime for months.

How's the battery? Low voltage will make for hard starting, even with points, especially if your rotor is old.

Dave
69S

ok its a new battery
plugs and leads are old but i am getting spark
fuel seems to be heaps there [maybe too much as when i pulled them plugs they were a bit wet from the fuel ]
wet sumping i drained that before i started and got a good 1lt or more out]
TDC by trial and error i found a convertabe position on my crazy centre stand and rolled it arond until it felt right
i did mantage to get a of bit fire in her belly but not for long only for onr or two kicks then nothing [now that sounds like someelse i share my bed with!] :twisted:
so ill give it a go today but first up im gonna take the bonnie for quick 1oo km dash thru some twisties 8)

macca47 said:

2 half throttle no choke

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hobot said:

Leave throttle closed at first, if no go then crack a bit

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I think that if you're not going to choke in cooler but not real cold weather, that is OK, but then going with half throttle, you're instantly "leaning out your tickle" so to speak. Might be enough to not start easily.

macca47 said:

plugs and leads are old but i am getting spark

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You're getting spark with the plugs exposed and not subject to the rigors of compression. If the plugs and wires are that old, I'd replace them on general principles.

I was getting spark on my old rotor and no battery, but it wouldn't start. As soon as I put the battery on, it started. Yes, wires and plugs are cheap and a good place to start. You can flood it, I've done it, but usually only when hot.

Dave
69S

My 750 will only start with closed throttle, try that before dismantling it.
Lightly tickle it first.

1. fuel on, tickle carbs
2. raise her to compression (gently)
3. turn key on
4. kick

the power arc can kick back if I raise it to compression with key on, best to turn off if the kick failed and start over

Hey Macca,
You might be flooding it.
Many Norton owners get rid of the Air slides (chokes), and find that a
good tickle and a handfull of throttle will usually do the trick.
Personally I'd leave the slides in, even if you don't use them, I think they
help to hold the Throttle slides from bouncing around.
Are you sure that you are useing the choke levers correctly.
I think Cowboydon has a used Mikuni setup if you want one.
AC.

I've got twin Amals, new Sparx three phase charging system, new Tri-Spark ignition, no choke.

1. Open fuel tap, tickle carbs real good (let fuel flow for a few seconds)
2. Push kick start lever through until up on compression.
3. Turn on ignition.
4. Crack the throttle less than a quarter turn.
5. Whomp down on the kick start.

Starts first kick, no kick back. Need to keep a hand on the throttle for a minute or 2 and then it settles into a stable idle around 600 rpm. When fully warm it idles at 800 rpm.

Hot start same as above with no tickle.

AussieCombat said:

Hey Macca,
You might be flooding it.
Many Norton owners get rid of the Air slides (chokes), and find that a
good tickle and a handfull of throttle will usually do the trick.
Personally I'd leave the slides in, even if you don't use them, I think they
help to hold the Throttle slides from bouncing around.
Are you sure that you are useing the choke levers correctly.
I think Cowboydon has a used Mikuni setup if you want one.
AC.

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Hey AC thanks for that info i will definately get to the next club meeting so hopefully will get to meet up with you then [ i didnt make the last one as i had to start work at midnight and was fast asleep when the meeting was on] in the mean time i will chase up anew set of leads and plugs and have another go
cheers

Norton Commando Starting Procedure

i. Cold
a. Tickle both carbs
b. Kick through 2-3 times
c. Turn key to correct 1 of 4 positions (on mine it’s clockwise to 2nd position)
d. Use kicker to find TDC and go just beyond or you’ll tear your ACL; don’t ask how I know this. She’ll also throw you onto the ground just for fun.
e. Kick like a @#$%&*. Usually goes second or third time if battery in good shape. Note the big “if”. If not, charging system should be checked. In mine, charging system will not keep up with running the headlamp.
f. Roll on throttle as you kick to “catch” the start
g. Warm up at least 30s

ii. Hot
a. Tickle only one carb or she’ll flood
b. Turn ignition on
c. Kick like a #$%^&*
d. Roll on throttle as you kick to “catch” the start

iii. Roll start
a. Find neutral and then place transmission in 3rd gear
b. Tickle carbs as above (either hot or cold engine). It’s an unlikely cold start though.
c. Hold clutch and let her roll downhill to fast walking speed or:
d. Have friend push until his spleen falls out
e. Pop clutch while sitting heavily on rear tire
f. Roll on throttle as you kick to “catch” the start and simultaneously pull clutch lever back in
g. Find neutral and warm up, although see b).

ANY carburetted engine usually responds best to a CLOSED throttle when cold. The vacuum needed to draw fuel and vaporize it goes away when it is opened even a bit, which is exactly what you DON'T want when cold/cranking speed. Certainly, there are exceptions, but usually masking a problem.

ANY carburetted engine usually responds best to a CLOSED throttle when cold. The vacuum needed to draw fuel and vaporize it goes away when it is opened even a bit, which is exactly what you DON'T want when cold/cranking speed.

Can you elaborate?
Every single carbureted engine that I have owned responded best to starting throttle off but cylinders loaded (ie step on the gas once or twice first) then rolling on throttle once it starts.
Am I doing something "wrong"?

Every single carbureted engine that I have owned responded best to starting throttle off but cylinders loaded (ie step on the gas once or twice first) then rolling on throttle once it starts.

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this is exactly my experience for the past 40 years

Was true with all my Amals and Mikunis.

I now have had JS Motorsport's 32mm flat slides for two years now, and with a cold motor the throttle must opened in order to draw fuel/air mixture into the combustion chambers while kicking to start.

A choke simply enriches the mixture, only the throttle is capable of opening the carb slide enough to suck the mixture into the chamber in order to meet the spark plug's spark and fire.

UNLESS, of course, there is a technique that involves NOT opening the throttle with cold motor that I am not aware of, and if so, please educate me?

roqueweiler said:

ANY carburetted engine usually responds best to a CLOSED throttle when cold. The vacuum needed to draw fuel and vaporize it goes away when it is opened even a bit, which is exactly what you DON'T want when cold/cranking speed.

Can you elaborate?
Every single carbureted engine that I have owned responded best to starting throttle off but cylinders loaded (ie step on the gas once or twice first) then rolling on throttle once it starts.
Am I doing something "wrong"?

Click to expand...

The "stepping on the gas once or twice" only works when there is an accelerator pump (like on cars). On the Amal, Mikuni VM, etc. there isn't so that's wasted motion, does nothing. The ticklers on an Amal provide the initial extra bit if fuel. Sounds like you have it right, tickle, kick, open throttle after itstarts as needed to keep running.

1up3down said:

I now have had JS Motorsport's 32mm flat slides for two years now, and with a cold motor the throttle must opened in order to draw fuel/air mixture into the combustion chambers while kicking to start.

A choke simply enriches the mixture, only the throttle is capable of opening the carb slide enough to suck the mixture into the chamber in order to meet the spark plug's spark and fire.

Click to expand...

Unlike a carb that has a choke slide or flap that physically restricts airflow, many carbs have a starter enrichment circuit, such as Amal Mk2, Mikuni, Bing, Keihin etc. where starter circuit air is drawn in through a separate passageway from the mouth of the carb so it completely bypasses the throttle slide (look in the carb bores "downstream" of the throttle slides of your flat slides and you will see the outlet hole for the starter circuit).

If the throttle slide is lifted off the stop during starting then air will be drawn in under the slide and not through the starter enrichment circuit, therefore opening the throttle weakens starting mixture. If a carb with an enrichment circuit needs the throttle held open in order for the engine to start then the "choke" jet is probably too rich.

http://www.mikuni.com/pdf/vmmanual.pdf Starter system section 3-4. and diagram p.3

Yep, that's the way. in my opinion.
My JS Flatslides work perfectly with no throttle, hot or cold.
Mikunis the same.
Amals, throttle needed.
I have always thought that the 'idle circuit' is the weak point of the Amals along
with the material used to manufacture them.
Hence, there are some good ones and some bad ones.
AC.

Ign. OFF , Fuel ON , Clear Clutch ( kick ) .
Pull Cylinders through (as appropriate.more cold )
Position pistons ( tdc ish )
position kickstart .
Leap upward and through weigh on foot crank .

Last Bit , Remarkable how fast you do it stalling / cutting sitting at a traffic light .