Kickstart RPM

Sorry not a norton twin , but i think when you see the tach just giggle at the bottom it must be about 200rpm , My Bsa B33 has M20 flywheels and 94mm stroke and that's mated to a Harley evolution piston +.030 nearly 90mm bore, so just under 600cc single .I've just reduced cranking compression from the shovelhead piston it had , I still have 170psi and the motor had been running that day but the cylinder was fairly cold , I've done up the magneto and changed it to slack wire full advance , it has big valves 45mm ex and 47mm intake , with a phf 36mm delortto pumper , I got it dialed in pretty good with AFR gauge , cold starting is good , use only a little advance, full choke and two pump shots and usually it's going in 1 or 2 . Starts ok hot but I need to get used to what it needs , but it can kick back , really badly ! I find it's best to not have my leg fully extended and if it kicks back I stay loose and don't fight it .😬
 
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The doctor let me take off my straight jacket so I can do some writing therapy.

This start RPM thing seems a little overthunk to me. I'd set the magic advance switch on the future magneto at 400 RPM. I doubt a Norton twin would run well enough for the ignition curve to be that important below or at 400 RPM. If that did not work, and the object was to use more ignition advance to improve idle, I'd try 250 RPM. Another option would be to include a potentiometer or dip switch to let the user set the advance start.
 
These work well. Will give a starter motor rpm. Handy when timing the bike single handed ,I.e , adjusting idle to 3000 rpm. It also appears they work on outboard and Harley's!!
 

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The yaki said:
These work well. Will give a starter motor rpm. Handy when timing the bike single handed ,I.e , adjusting idle to 3000 rpm. It also appears they work on outboard and Harley's!!
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I have one on my lawnmower. Also reads run hours when engine is stopped. That is, until the internal battery dies.
 
Any bike can be kick started easily. All you need to do is turn it over once, slowly with the kickstart to get mixture into it - then push a piston about 2/3rds towards TDC to get compression. and give it a strong controlled rapid push past TDC - throttle closed. It should fire immediately if the idle has been correctly adjusted. If you kick and twist the throttle at the same time, it usually will not start. And never bounce your foot on the kick-start. If you don't keep the pressure on, you will get bitten if it kicks back. For me it is twice as bad - I have a piece of bone missing from inside my right knee joint and no cartledges. I can still kick a bike over without getting hurt.
Do not stand there trying to get revs - one firm push past compression should be enough - and stand astride the bike -not beside it.
 
acotrel said:
Any bike can be kick started easily. All you need to do is turn it over once, slowly with the kickstart to get mixture into it - then push a piston about 2/3rds towards TDC to get compression. and give it a strong controlled rapid push past TDC - throttle closed. It should fire immediately if the idle has been correctly adjusted. If you kick and twist the throttle at the same time, it usually will not start. And never bounce your foot on the kick-start. If you don't keep the pressure on, you will get bitten if it kicks back. For me it is twice as bad - I have a piece of bone missing from inside my right knee joint and no cartledges. I can still kick a bike over without getting hurt.
Do not stand there trying to get revs - one firm push past compression should be enough - and stand astride the bike -not beside it.
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Yes some bikes can be started like that but definitely not "any bike" you are talking complete rubbish as usual
 
acotrel said:
Any bike can be kick started easily. All you need to do is turn it over once, slowly with the kickstart to get mixture into it - then push a piston about 2/3rds towards TDC to get compression. and give it a strong controlled rapid push past TDC - throttle closed. It should fire immediately if the idle has been correctly adjusted. If you kick and twist the throttle at the same time, it usually will not start. And never bounce your foot on the kick-start. If you don't keep the pressure on, you will get bitten if it kicks back. For me it is twice as bad - I have a piece of bone missing from inside my right knee joint and no cartledges. I can still kick a bike over without getting hurt.
Do not stand there trying to get revs - one firm push past compression should be enough - and stand astride the bike -not beside it.
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How long has it been since you kick started a bike Al, don't your RACE bike have a roller starter, as with Amals you do have to give that little bit of throttle, not much but just a little, no need to tickle if its been run, only tickle when cold.
I watched a YouTube video a while back a shop trying to KS a 72 yellow Norton, they had no idea how to KS a Norton and after 2 or 3 lazy kicks they kept tickling the carb and all it was doing was flooding it and they also had the choke on/off the wrong way, they were just kicking it with very short kicks and not getting near TDC or on compression, after about 30 kicks it started to fire but with a belly full of fuel and the kicker was telling the other person this is how you do it, was so sad to watch the seller just had no idea at all, would have put the other guy right off.
 
ashman said:
How long has it been since you kick started a bike Al, don't your RACE bike have a roller starter, as with Amals you do have to give that little bit of throttle, not much but just a little, no need to tickle if its been run, only tickle when cold.
I watched a YouTube video a while back a shop trying to KS a 72 yellow Norton, they had no idea how to KS a Norton and after 2 or 3 lazy kicks they kept tickling the carb and all it was doing was flooding it and they also had the choke on/off the wrong way, they were just kicking it with very short kicks and not getting near TDC or on compression, after about 30 kicks it started to fire but with a belly full of fuel and the kicker was telling the other person this is how you do it, was so sad to watch the seller just had no idea at all, would have put the other guy right off.
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...and, the Harley guy running the dyno at Cabbage Patch near Daytona couldn't start my RZ350. He gave long slow kicks and nothing happened. 😜🤣
 
Every bike requires a different starting technique. My 1975 RD250, a couple of swift kicks. 500 Goldie ease over compression, then a long kick (or pull in the decompressor, spin over with the electric start and release the decompressor)
With Amal concentric carbs which do not have a dedicated start circuit it is essential that the pilot circuit is perfect. The non removable pilot jet is prone to clogging, use a 0.016" drill bit to clean
 
Most difficult Commando I have kick started was a Yellow Peril Production racer replica.

Such a long stretch to the clipons. Seat way back. Tank high at the back. Faring catching your wrist if you sit up. High compression.

Trying to get a decent swing on the kick-start is nigh on impossible unless your 7 feet tall.

Not a bike for the over 60s. 🤣🤣🤣🤣
 
I still can't workout why in how much RPM for kick over starting, I just kick the fu cker and never ever thought about it in 49 years but throw this one in, the Joe Hunt fires on first kick every time at full advance without any kickback at all whether a full kick when cold or a lazy kick any other time without using side or centre stands for kicking and with a lot more compressing than a stock motor even at near 67 years of age, the JH has been the easiest kicker of all time since on the bike and with the Amals they work so well together.
I know you all heard it before but can't understand why so many are processed with retarding for kicking and kickbacks, I think in 49+ years my Norton only has kicked back a few times when it has a belly full of fuel (flooded), if timing and carbs set right they should never kick back and found out a long time ago the deg plate and rota line can be out by a bit as well I have never used a timing light, 14 years now with running the JH and still has the original point and have had no problems at all, just pull the front cover on oil changes, check on the point condition and a dab of STP oil on the felt to lube the points cam, when running and starting first kick I leave it alone, the cover was replaced when I went for a slide down the road and crushed the condenser.
I have now 3 tune up kits and 2 spare covers sitting in my parts cabinet just in case I need them when ever lol.
 
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robs ss said:
We seem to have drifted away from the OP's question,,,
View attachment 120453
;) ;)
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We did have some good suggestions.

But it is a " It depends question." Getting any speed at all on a Yellow Peril is a real challenge.

The original question was to address a particular situation.

robs ss said:
Why do you ask, two dogs?
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"For creating a new magneto style ignition with an internal switch that goes to full advance just above kick start speed to avoid kickback. "

Maybe an alternative approach could be to set full advance above say 1500.

Which would be above any reasonable estimate of kick start speed but below riding rpm. Idle speed should be fine with retarded ignition.

I don't have any retard mechanism on the magneto on the race bike. These days I start it on rollers but in the past could easily bump start it. (Pre 60 years of age. 🤣🤣🤣)
 
NORTSTER1974 said:
Concours, did you get to wrestle any of the "woman" in the cole slaw patch?:) While the dude was dynoing your bike?
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No.... I'd heard about it.
I've seen the midget wrestling at the Last Chance Saloon in Port Orange (or New Smyrna)
🤡😜🤪

There was this beautiful 6'-2" Greek woman from Flagler Beach, we wrestled a bit, she was on top a lot.
 
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