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!
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.
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.
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.
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.
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.
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.
Here's a bit of commentary on this starting business to ensure we are all on the same page.
TDC is top dead center. ON a 4-stroke engine there is TDC on compression and then again at the beginning of the intake stroke. The compression stroke which is just before TDC is when the engine is very hard to turn over. That's when you use the decompression lever too release the compressed mixture so you can ease the motor over TDC. I do all this with the ignition OFF because sometimes it will fire (or backfire) as you ease up to TDC. Remember the engine fires a few degrees before TDC and it can go backwards. Once you ease over TDC on compression it is important to continue pushing the kick starter about 70 more degrees till you feel the springiness of the exhaust valve opening. Then reset the kicker. The reason this is important is because this gets you closer to the next compression stroke for firing and the engine will be turning faster and have more momentum. BSA says to get just past TDC which I did for years until I experimented with going well past TDC and finding that this little step makes starting easier and eliminates kickback if the engine does not start. I learned this when I was at wits end trying to consistently start my B50 which is more difficult than the B44. Don't forget tickling and priming (when cold) and all your other drill stuff.
When I started my B50 this spring after sitting all winter, it popped on the first kick and started on the second with year old gas. When I came home from a ride, I started it five times in a row on a single kick. This brings be to a point that Lannis made earlier in this thread. If you let the bike sit about 10-20 minutes (like at a gas stop) it can sometimes be problematic starting. I find what works best is a very light tickle because the gas in the throat of the carb and manifold evaporates because of the heat. I will admit that I have had most trouble with this. Cold starts and hot starts are no problem ever, but some times these intermediates between hot and cold are troublesome. The light tickle gets just enough gas in there that you don't flood it and drown the spark plug.
I almost sold my B50 when I found it to be such a cantankerous starter. I spent a winter perfecting starts and the result (for B50's) is posted on the B50 site and it really works well. Motorcycles are like outboard motors...I won't own one that doesn't start reliably.
On chokes, I found they do work but you have to pull them off IMMEDIATLY to prevent stalling. Flooding the carb with a tickler like they do on small Briggs motors with a little bulb seems to work just fine without additional complexity of a choke mechanism.