Tricks to starting a 1971 BSA B50SS (500cc single)?

[supercrouton]

I am looking for the input of people who have owned, or worked on, the 1971-2 BSA B50SS, and that have the “knack” for consistently starting these machines. Hopefully a few of you could share the sequence of actions or subtleties with me, on getting this machine on the road. I got it running yesterday, and it actually ran really well, but I have not been able to get the sequence for consistent results starting it.

Timing, ignition, proper mechanical condition, carburetion and electrical are all sorted, so at this time I don’t need troubleshooting advice, just what you have found works to consistently start these thumpers most every time. This bike kicked the holy crap out of me the last time I started it several years ago and I’d rather not be crippled for three weeks again.

Thanks in advance, Dan.

[beaverbikes]

Here's one thing might help if you haven't tried it yet. Experiment with raising the slide a little with the screw, and then do not crack the throttle with your hand while kicking it.

[Tony the torch]

the B50 is likely the hardest bike to start, but if you put the piston just past TDC on the compression stroke and with all your might really give it a spin it should fire.

[chuckspeed]

Tony's advice is pretty good. I've had a few bikes really muck up my foot and ankle from the kick.

Couple of non-traditional thoughts on the subject:

1. Valve Lash - I've discovered a motor with lash set a tad tight (tight fit on the feeler gauge) seems to spin a little more easily. I attribute this to compression bleed-off from extension of the cam duration - some of the opening ramp is used. Motor's a little quieter, too. This is a very subjective thing, and I don't advise it unless you know what you're doing.

2. Discovered this one by accident - if the clutch spring basket is adjusted to the lightest tension possible which still holds, the clutch will 'give' a little on kickback, saving your leg. Just had this happen yesterday on an A65. I'm glad it gave - last time one kicked back, I limped for two weeks.

I HATE kickback. Ankle and bottom of my foot have been black and blue more than once, and at my advanced age, I don't heal as quickly as I did before.

Hope this helps.

[supercrouton]

[QUOTE=Tony the torch;704340]the B50 is likely the hardest bike to start...... [QUOTE]

Thanks Tony! Your first statement does make me feel a little better about struggling with this beast,

[MIKE47]

I use tony's technique on my Honda thumper. Just past TDC and kick like you are trying to break the pedal.

[supercrouton]

^^Thanks!^^

So, there is no need to use, what I am assuming is, the compression-release lever on the left side of the handle bar? I'd love to get rid of that lever if it's not needed.
Cheers, dan.

[MIKE47]

Well, if you have one of those you could make it useful and save some effort. I'm not so lucky. The flat trackers used them as Jake Brakes in the corners so as to not load the front end. Could easily serve the same purpose on the street.

[bruno desmartass]

I'd love to get rid of that lever if it's not needed.

Doesn't need to be on the bar, but very handy to have, esp for getting to TDC. Maybe shorten cable, mount to frame somewhere's. Bruno

[Hoofhearted]

Originally Posted by supercrouton

^^Thanks!^^

So, there is no need to use, what I am assuming is, the compression-release lever on the left side of the handle bar? I'd love to get rid of that lever if it's not needed.
Cheers, dan.

With all singles the compression release lever is your friend. Love it, caress it, wear it proudly on your bars. The trick is to bring the piston up on compression. Use the compression release to ease it over compression. Just past TDC. You will learn that in time. The whole idea is to give the flywheels and piston a running start at the next compression stroke. Inertia if you like. If you have an ignition retard lever, retard it a hair. But I think you may have an auto retard. Depending on the carb and weather, choke it or if you have an Amal, tickle it. Obviously the choke won't be needed if the engine is warm.

Give it a good kick. Try not to lock your knee at the bottom of the kick. That way if it kicks back your knee can flex and your hip doesn't wind up just under your armpit. Once you figure it out you'll have a one or two kick bike. Plus you'll be able to make a few bucks at the local bar by betting people they can't start your bike in 3 kicks or less.

[chuckspeed]

Originally Posted by Hoofhearted

With all singles the compression release lever is your friend. Love it, caress it, wear it proudly on your bars. The trick is to bring the piston up on compression. Use the compression release to ease it over compression. Just past TDC. You will learn that in time. The whole idea is to give the flywheels and piston a running start at the next compression stroke. Inertia if you like. If you have an ignition retard lever, retard it a hair. But I think you may have an auto retard. Depending on the carb and weather, choke it or if you have an Amal, tickle it. Obviously the choke won't be needed if the engine is warm.

Give it a good kick. Try not to lock your knee at the bottom of the kick. That way if it kicks back your knee can flex and your hip doesn't wind up just under your armpit. Once you figure it out you'll have a one or two kick bike. Plus you'll be able to make a few bucks at the local bar by betting people they can't start your bike in 3 kicks or less.

+1 on Hoof's comments.

Kickers (on production bikes) have been gone so long folks have forgotten how to kickstart stuff. Guys who git on board and start flailing away are setting themselves up for a sprain - or worse.

There's a dance to the kicker/throttle/compression release; get the sequence right and it looks dirt simple - like anything else, it takes practice.

And no - the CR should be considered an element of coolness - like a bike that came out of the box with a hand shift.

[supercrouton]

Wow, Thank you guys for the help! Now I feel more confident about getting this thing to light off more consistantly. I will keep you posted on the results.
Cheers, Dan.

[chuckspeed]

Super -

One more thing...You'll learn that a kicker bike always runs better than an e-start, as no one riding a kicker wants to beat themselves up starting it. You'll probably figure out how to tweak it to run even better.

I just had to kick my A65 over four times this AM - discovered the idle circuit was a half-turn rich. Kickers make you listen to your bike.

Finally - never attempt to start one with a bunch of women watching. Kicker bikes know when wimmen are around, and they get their jollies by tossing you over the bars.

Enjoy.

[supercrouton]

Thanks for the help. All I build and ride are kick-start bikes, specifically Triumph twins. They are tuned to be one or occasionally two kick bikes, that is why this single had me so frustrated. The only times my '56 Trump has failed to start is when I forgot to switch on the magneto.

[chuckspeed]

Originally Posted by supercrouton

Thanks for the help. All I build and ride are kick-start bikes, specifically Triumph twins. They are tuned to be one or occasionally two kick bikes, that is why this single had me so frustrated. The only times my '56 Trump has failed to start is when I forgot to switch on the magneto.

Big thumpers kick hard!

[Hoofhearted]

I have a Weslake 500 single in my Norton. I used to kick start it but when I got it to 14:1 comp., 36 deg. fixed advance and no compression release I had to build an electric starter that runs off the crank. Couldn't kick it anymore.

[ob1quixote]

My experience from 441's

Tickle the carb about 4 seconds, until a little fuel gets on your tickling finger.

Pull the decomp lever in and pull the fuel into the cylinder with 3 "dry" kicks, applying about 1/4 throttle.

Slowly kick it to TDC, and crack the decomp lever to let it past TDC.

Turn the handlebars a little to the left, just in case a kickback wants to send your knee into your thumb underneath the throttle.

Kick with authoritIIII, closed throttle but ready for that lil twist she might want to get urged into life.

[gravley]

Would you like to talk with an older gentleman who was a Datona Sand racer named Ace Meyers. He loves the 500 BSA's, And has a very nice Goldie.

[1963trump]

all of the above advice is great, but here's something I learned from racing a big thumper.
Put the bike into 2nd gear
Roll it backwards against TDC
Pull in the clutch
Take 3 steps forward, jump on "side-saddle" and dump the clutch.
Works like a charm.

[Kojack]

Hoof's and the other's remarks on using the compression release are on the money. Keep in mind, the whole kicker mechanism on these bikes was originally designed to start a 250. Doing away with the compression release on the bigger singles and just kicking your ass off will take it's toll on the kicker parts, not just your body.