[johnnypence]

i have my 72 tiger, boyer box, pretty well dialed in. it starts reliably on the first or second kick after the tickle/kick (ign. off)/tickle/kick (ign. on) procedure -- EXCEPT when there's a discerning-looking harley guy or a cute college girl checking me out. in every single instance i will wear out my knee trying to get that thing going. the more i am being checked out, the less likely it is to start right away.

this is clearly a case of adjusting the mojo, and i am prepared to devote some time to trial and error, but i wonder if anybody has experience with this and can tell me the proper settings.

 

[Mecchanica]

Monitor your throttle hand. Most bikes start best with little or no throttle twisted in. If you whack open the throttle while kicking, there isn't sufficient vacuum to pull fuel into the main air choke.

 

[OzBloke]

I find the opposite to Mechanica. I give it a good tickle, twist the throttle open about a 1/4, then give it a good kick. Works every time for me. Concept is that tickling leaves fuel lying in the throat of the carb, and it needs oxygen to burn. Othewise it's too rich.

 

[johnnypence]

i like the phrasing, "monitor your throttle hand." it is possible that somewhere in my brain, i'm saying "check THIS out" and cracking the throttle even though i know not to.

this bike is more like a horse than any machine i've ever known. it loves attention, hates neglect, and has its own sense of humor. give it a treat like a little marvel mystery oil and you'll have a friend for the rest of the day.

it hasn't looked me in the eye and stepped on my foot or tried to scrape me off on a barbed-wire fence yet. it also doesn't make me sneeze. but nonetheless very much like a horse.

 

[Mecchanica]

Depends on the jetting...I keep mine a little rich to mitigate the tendency to ping caused by the higher-than-stock compression and high gearing of the 68, so I can use a little more throttle. But, a "properly" adjusted carb shouldn't need much throttle....just a tad, as they say down south. But if, in your eagerness to show that cutie what a kickstarter looks like, you get the throttle open halfway or more, it probably won't start.

 

[johnnypence]

my tone grows slightly more serious about this:

it seems like the trouble starting comes when the engine is neither hot nor cold, but when it just rode a few blocks. i usually start off a ride with a gas top-off, and the gas stations are pretty near my house. i also rode to an appointment yesterday just a mile away. nobody was checking me out at all, my hand was off the throttle, and it still did the same thing.

it'll turn over after about 5-10 kicks instead of 1 when it's "warm" like this.

i've also noticed that as the engine gets warmer my idle will speed up just a hair.

some folks talk about an insulating asbestos bushing between carb and intake manifold. i have a gasket there, but it's not real thick. the carb gets warm to the touch during a ride.

are these phenomena related?

 

[GulfCoastDave]

Johnny ...about the difficulty when the "engine is neither hot 'nor cold"... I've experienced the same thing on bikes through the years. You have a machine set up properly & it starts great cold & it starts great hot... but that little zone in-between can be troublesome. Air temp is also a factor. It's a question of determining what it is the bike wants... a leaner or richer mixture. Opening the throttle a bit will lean it and using a little choke or giving it a small 'tickle' will enrich it. Next time you are 'half-hot' try one of the alternatives. Of course the degree to which you feed it (one way or the other) is a mystery also. A little tweak of the mixture screw might also help.

The ability to master these system nuances is the art of operating a classic motorcycle. Any fool can jump on a modern bike, turn on the key and press a button. Computer chips monitor air & engine temp and meter out fuel precisely so no thinking is involved.
For me, the little mysteries are a big part of what makes it fun.
Best regards,
Dave

 

[CommandoRdster]

Johnny- although I've never had a problem starting any of my twins, I have a BSA B50MX that exhibits the same behavior you describe. Starts easy when cold, but a bit dicey when warm. An old Gold Star rider gave me a little tip that seems to help quite a bit. Shut off your gas tap about 30 seconds, or half a block,or so
before you shut down the engine.That gives you a little room in the float chamber, for any fuel left in the line that might dribble past the needle & seat. Too much fuel running into the float bowl, with the engine off, in essence gives your bike an unintended "tickle", which will usually make a warm engine a bear to start.
Running AMALS are you? Good for you! Might be a good time to check float levels, needle & seat, etc.

Who cares what some fat-a$$ed Harley rider thinks, anyway? :chug:

 

[CommandoRdster]

[ This message was edited by: CommandoRdster on 2006-12-15 00:28 ]

 

[johnnypence]

that sounds like a reasonable idea train of thought commando. i'll check it out.

 

[Mecchanica]

I would think a little mixture tweak should help. Also check the valves. Maybe they tighten up when slightly hot to lose a little compression, but when thoroughly hot, the bike runs rich enough to compensate?
As the engine heats, it vaporized fuel more effeciently and so runs effectively richer, hence the enrichening devices on carbs for cold starting and that's why you don't tickle a hot engine...it's already rich enough, if the mix is set correctly.

 

[johnnypence]

just as a practical matter: i set the valves this summer, and tightened the nuts up pretty good. assuming i did it properly, would they have shimmied loose since? probably not even 1000 miles since i set them.

 

[peintremondain]

hi johnny,
looks like a matter of carb tuning.when you'll be fed up with amal you ll discover the virtues of a well made carb:dell orto or mikuni....the best mod i did on mine(and almost the only one)
ben

 

[GrandPaulZ]

It's all in your head.

You need to live in the world where you and your bike are the only things in the universe. When you grip the handlebars and stand on the kickstarter, it says hello, where do you want to go?

 

[CommandoRdster]

GPZ, you said it all right there. Zen and the Art of Motorcycle Starting.
:-D

 

[wagonboss]

The old Trumpets didn't like any throttle movement while starting. Hard not to twist the grip sometimes if you're putting your weight behind it. Old trick, tickle the carb/carbs, just crack the throttle, then grab the front brake lever, then kick it through. Grabbing the brake lever basically holds the throttle in place, keeping you from twisting it. It's always harder when someone's watching, you try so hard to be sure it starts, you forget the drill.