Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board B44 hot starting issues

After 3 years, I finally have my 1966 B44 Victor Enduro (relatively oil tight) and on the road. It now starts ok from cold after a few kicks and runs great. But it will not start when hot and I have to let it cool before restarting.
Does anyone have any advice for hot starting? Many thanks in advance!

1. Fit a thicker spacer between the carb and the head, minimum 1/4" thick, fit longer carb mounting studs if needed. This reduces the heat getting to the carb.

2. Fit a choke, oddly my B44 starts well when hot with the fitted choke turned on, it has to be turned off immediately as it 8 strokes as soon as it catches. Believe this helps the carb as on singles, the pull on the fuel is low and the hot fuel loses its volatile parts so less likely to ignite so a temporary increase in fuel helps.

3. Fit an extended throttle screw, easy to adjust with a gloved hand so with a hot start you can turn it in 1/4 turn as this can also help.

4. Before I fitted the choke I found opening the valve lifter and kicking the engine over until a loud bang came out the exhaust and then closing the valve lifter before kicking for starting worked. Maybe it cleared out some fuel that had lost its volatile part from being hot.

Either you have an air leak at the carb manifold or you set your idle circuit for the carb on a cold engine.

With the motor running, spray some easy start or carb cleaner around the carb manifold, if the engine revs change then you have a leak.

If this is good then, try and get 20 miles in then adjust the mixture.

You might require then raising the slide a touch to start if you don’t have a choke fitted when cold, personally I’d fit a choke.

Okay I'm going to add my 2 cents........which is worth less than that!

ALL the above is good advice and I agree with all of it.

You wrote............"from cold after a few kicks and runs great"

It could be something as simple as you haven't figured out what the bike's drill is..........but it "should" start with one kick. So........something other than hot starting is trying to tell you something.

I did chase a "hot start" issue I had on a B44 down to a bad coil. Somewhere along the line I felt the coil and it was hotter than it should have been........I was doing the same as you, had to wait for it to cool off. Just something else to check.

Good luck and keep at it.......you'll sort it.

Gordon

I agree with Gordon about figuring out "the bike's drill".
I have 2 B44s and they a subtly different but both start with one or two kicks, once the "correct" pre start drill is used, ..... they sulk if you get it the wrong way around!
Both have new premier AMAL carbs, both have new Vape sparky bits and both have new coils.
With one of them, from cold, I ALWAYS use Komando's , tickle, decompress, throttle wide open, kick 5 times, release valve lifter, then kick like you mean it technique ... fires first time.
With the other, forget that! ..... tickle, leave it while you put your helmet on, then kick like you mean it ...... fires first time .If you put your helmet on first ..... well better just take the first bike 'cause this one aint going nowhere.

When "warm", and how warm is a fine line, tickle a little........ if "hot", definitely NO tickle.

Now just for bad mindedness they will change their individual requirements seemingly at random. The second one ... for no apparent reason, has recently developed the habit of seemingly shortening it's clutch cable when it gets warm (....... HOW???!!!) requiring me to loosen it off at the lever or the kicking is somewhat ineffectual. Of course that means when the motor is cold I have to tighten it up again or gearchanges tend to be rather noisy affairs.
Of course it goes without saying, never, and I mean NEVER, work on any other vehicle what so ever where they can see or even hear you doing so.

More seriously, how is the clutch? I have had (with one of these, and with other bikes 40 odd years ago) where the clutch would slip a little when the motor (and clutch) was warm ....... better compression?? ...... shows up more when starting rather than running.

Thank you for the wealth of knowledge in super quick time chaps! The clutch is brand new and not slipping, so no issues there. The carb and all cables are also brand new. I have two heat spacers fitted, but maybe I can go with a thicker one.
I came across this finned carb manifold online: https://www.ebay.co.uk/itm/334313293693?hash=item4dd6a0077d:g:Xl0AAOSwLEth-VdP Any thoughts on this or is a thicker spacer just as good, if not better?
Fitting a choke is an interesting option; I will look in to that! And yes, I definitely need to refine my starting technique; all of the above advice will be experimented with this weekend!
Thanks again for all of the speedy help.

The ebay finned one will not work as its not heat resistant and it will heat up, the airflow is non existent across the fins too. It would only work as a spacer with proper heat resistant material both before and after and by that time the room for an air filter would be limiting.

Use of the valve lifter to get the motor "just over" compression is pretty important, but how far is "just over"? it is a bit further than you think.



I have linked to this video before, but it is pretty good at showing. Of course this is for a cold motor, if you tickle the carb on a hot motor you will flood the engine, so don't do that bit!

Sometimes some bikes need a brief tickle when hot.

Dave Martin........I feel your pain brother. THANK YOU for the laugh this morning.

I have several unit singles and their drill is "almost" the same for each but they do differ a bit.....my 67 C25 will NOT start if you turn (no matter how slight) the throttle while kicking. WHICH is freaking almost impossible for me to do......I've tried all sorts of stuff. I start my bikes while sitting on them.....never on the stand. My right hand has nothing to do.......except hold the throttle. Grrrrrrrrrrr.

I have valve lifters fitted to all my unit singles (even the 250s) but I don't use them. Instead I put the bike in second gear and back up until it stops. Some folks ( Mr Mike) hate doing it that way but I don't mind it at all. The ONLY time I get frustrated with it......is on the third kick because by then I'm pissed.

Chokes......got them on all my unit singles but one (the one I didn't set up). I tend to tune to the rich side so I very seldom ( read almost never) use the choke....I have to be honest here. I do believe if my bikes were set up properly (has to be someone other than me then) I'd probably need them. BUT....why did BSA leave them off some unit singles in the first place?

It's a puzzle............keep at it jcj551......you'll get all the pieces sorted if you stick with it.

My guess is..............................the bike could be pissed it can't mark it's territory.......your fault for fixing the LEAKS!!!!!

OR........since you said you have two spacers installed......like Alan mentioned you might have a slight air leak between them? ( only useful comment on this reply?)

Proud to be one of the BSA unit single guys.......Gordon

PS.......never.....I mean NEVER try to start one if a good looking women is watching. Come up with some excuse to walk away until she's gone. Trust me on this one.

I have found that B44's are generally easy starters. Just reinforcing(or contradicting) what has already been said, i offer the following:

(1)( Stone cold..... tickle liberally and kick a couple of times with WOT before starting drill..
(2) Tried chokes and find them unnecessary...just one more thing to keep after.
(3) Fit all with a thumb screw so you can bump up the idle a tad for starts and turn down to get tickover just right.
(4) Hot starts, "No tickle".
(5) Keep pilot absolutely clean.
(6) See my starting drill for a B50 over on the B50 site.

Mr MIke

Since ripping the right hoof off I now have no ankle cup so kick starting with the right foot astride any mororcycle is a non event.
Because we humans are adaptable creatures and can modify how we do things I learned how to kick start left footed standing next to the bike.
At that time running I had 2 WD B40's , usually easy starters + a B50T unbelievably difficult to start hot or cold + OIF A65 L easy starter cold difficult hot

Without doing anythng to the bikes suddenlythey all became much easier starters so I wondered why
Watching others it became very apparent
IT was twisting the throttle while leaping on th starter from agreat height holding onto the handlebars
When standing next to the bike, you do not actually change your stance so you dont need a death grip on the grips
Also you are closer to the engine, close enough to actually here the carb breathing and the exhaust relieving when you have the valve lifter in operation.
On top of that, you only have your muscles to kick the kick starter rather than body weight to jump on the leap starter .

The upsht is you always get the piston in the right spot for an easy start
next you don't accidently open the throttle
Finally and most important you can follow through the KICK all the way to the stop and hold it there so ZERO kick backs .
This of course builds up your confidence and from then on it will be an easy start .
That is probably the best bit 40 years latter & I am yet to ever have a kick back no matter whose bike I am swing the starter on .

You can do the same thing with your right foot but that has standing at an akward angle to the bike so not stable on your feet as left footing does .

And for those who think your are too whimpy to do this , back in 2006 I showed this technique to a tiny 17 year old woman who would be lucky to go 60lbs soaking wet in her riding gear .
She had a B25 that she was getting others in her group to start for her
After 15 minutes she was confidently starting it first kick, in fact she must have done 20 starts in a row beaming from ear to ear with not a single kick back which used to happen every time she tried to start the bike astride with it on the centre stand .

I have tried starting by standing astride to start it and is like eating with your off hand. Not saying it won't work but after over 50 years of starting astride I'm not about to change. Never get a kickback it you kick all the way thru and start you kick when the exhaust valve is starting to open. You can feel the springiness. It's well past TDC .

It is just a problem of geometry
If you kick with the ball of your foot and the bike remains on the back wheel then you can get to the stop
If you sit the pedal against your heel as most do then your shin hits the foot peg before the kick start quadrant hits the stop
If the bike tips forward onto the front wheel then you need a C shaped shin .
Different peoples leg & foot lengths will of course vary this a bit .
It took a while to get used to because it did feel wonky at the start
But we are humans and humans learn to adapt and when it is a case of left foot kick or walk then then left foot kick it is .

I agree with just about everything above because all bikes behave somewhat differently. Gordon mentioned the coil. Hot coils notoriously won't create spark on many vehicles, not just motorcycles. I would first assure myself that I had good spark once the machine has been ridden and is hot and won't start. If you don't have good spark when the coil is hot, replace the coil. I had a B50 once upon a time and I had significant issues starting it astride the bike, due to kick-backs. I took to only starting it with my left foot standing next to the bike. Worked great. When I got my current B44, I tried the same starting procedure. The bike didn't like it. I now always start my B44 astride the bike. When cold I really tickle the carb a lot. I then pull the compression release and with the ignition off I turn the engine over 5 times. I then bring it to just past TDC and it virtually always starts on the first kick, after making certain that I don't open the throttle. When hot I never tickle the carb and it virtually always starts on the first kick.

Note: This B44 was very difficult to start until Beno Rodi set the timing and carb for me. Beno knows BSA motorcycles!

The awkward and subjective thing about starting British bikes with AMAL carbs is not the Cold Start technique, which is usually consistent from day to day, nor is it the Hot Starting technique, which usually involves cracking the throttle with a screw (or on big Yamaha singles, a lever) and avoiding flooding it.

It's the in-between starting technique, where it's had a few minutes to cool down (i.e. you're not restarting it after it stalled in traffic on a hot day), so it's too warm to need the choke, but isn't hot either. There's a continuum of conditions that might apply, and you have to guess where it's at. Gas-foul the plug and you're hosed .... !

Lannis

I don't get the "taking it passed TDC" concept. Once passed TDC there's no spark for another 720 degrees of the crank rotation. I figure you feel resistance at the bottom of the compression stroke and with the decompression lever you advance the piston to just before TDC not after.

Once you get a bit past TDC on the compression stroke, turning the engine over isn't compressing air until the next compression stroke. That allows the maximum amount of travel to build up momentum during the next intake stroke and before the next spark.

Strictly, during the leg-powered "power" stroke, there is negative compression as the piston descends with the valves closed, which is why Mr Mike recommended turning over until the exhaust valve starts to open. That gives the entire valve-open period to build up momentum with the least load on the entire starting train.

One of the problems of the B25 not having a decompressor is that it can fire while being eased over TDC, which more or less provides enough momentum to get to the next compression stroke, where you have to start all over again. I've got into the habit of turning the ignition off while easing it over TDC.

Do you start a single like that? Strange.

We use the decompressor to get past TDC at the end of the compression stroke so that the kickstart imparts nearly 720 degrees of acceleration on the flywheel, to carry it over the the next compression stroke.

kicking to quickly into compression
sounds like an excellent method to risk leg damage .

you kick after-TDC
to allow the full leg kick
to be delivered into the flywheel , before the risk of a kick back .

and kick-back potential is further reduced
because the engine has gone through an intake stroke .
setting up the cylinder mixture for proper ignition

The kickstart hearing s different B25 to B44 due to 28 and 23 engine sprocket tooth count respectively. So with the lower gearing on the B44 the kickstart moves the piston less so you need to go past TDC, still good practise on a B25 but with the higher path travel you can kick just before TDC if the compression has time to leak away.

So when starting my B44s the "just after TDC" feels like a definite "notch", just like the guy in the video says.

So it is up to compression, lift the valve and continue until you feel the notch .... this is about 1/4 to 1/3 of the kick start stroke, re cock the kicker, then kick like you mean it with a long full stroke.
One day, if I can be bothered, I will observe the valves to see where in the stoke this notch is, but it kinda feels like BDC?
Neither bike has ever kicked back but this might have something to do with the Vape.

The “guy” in the video is the same fellow that first commented on the “ just past TDC” thing yesterday.

I think I’m getting compression and TDC confused??? Cause I’m pretty sure we’re all doing it the same way as his video. You see him finding compression then releasing the pressure THEN moving past it a bit with the kicker.

For some reason I “think” Mr Mike moves his even further?

So my question is……..if I move the kickstarter until I reach compression. Then release the pressure with the valve lifter. Then move the crank a little ( like he does in his video)……..where’s the piston now in relation to TDC? He said yesterday that he stops the piston just before TDC. Where is the piston when you first reach compression in relation to TDC?

Gordon

That depends on the state of the engine in terms of compression, how modified the engine is say with barrel spacers, how strong your leg is and how much you weigh, kick start gearing etc. So no clear answer so the statement by itself is fairly useless. I just go by the little notch or easing you feel as you just go over TDC. You know where you are then. I use the same method on twins too especially on the 850 Commando, no valve lifter so you stand on the kickstart and let the compression leak away until TDC.