Everything seems right, but not starting

I bought. 71 Commando. The battery was shot, it was completely wet slumped, and the gasoline was old and either separated or had water mixed in. I got the bike for a low price, so I wasn't concerned. Rather than spend time getting it running as it was, I started my upgrades:
Paton ignition
Podtronics rectifier with capacitor
Li ion battery
New:wiring,fuses hi amp stator,nos lucas rotor, dual 6v lucas coils, ignition switch,plugs (correctly gapped),resistor plug cables, dual amal premier carbs.
Removal of old, unnecessary components (zener, coil resistor,)

Flushed fuel tankChanged oil
Static timed the bike to Pazon specs

Okay, time to kick it over...
Nothing much happens.

Okay, check everything.
Spark-good --checked with dummy plugs in and out
Pazon properly aligned, tested with different module in place
Fuel gets to cylinders
Grounds all good, wiring continuity good, no shorts or drains
Retimed to other rotor mark, checked TDC

Still, no start.
Some heavy kickback especially after advancing the timing A lot)
Verified cam timing was properly set (correct tooth)
Even tried some QuickStart (shudder!)
Result: Sore leg from kicking

Attempts at rolling starting were equally unsuccessful.

Ideas?

So you don't reaally know if it was potentially a runner before your work started.

You don't mention compression?

Assuming you didn't pull the head and barrels off (you don't say), the rings may well be gummed in the pistons, and/or the valves may not be seating well, or if there could I suppose be problems with the cam lifting the valves. I have to say that with an unknown bike like this I would also worry what the inside of the oil crank sludge trap is like for when it does run. How did you flush the motor?

You do mention resistor plug cables, so I assume you don't have resistor plugs fitted? Too much resistance could lead to a weaker spark!

Get the 6 volt coils properly checked on tester (if you can find someone who has one these days), I did have a pair once that gave good spark at the plug, until the plug was put into the cylinder!

I assume the coils are wired series to suit the wasted spark ignition? hence the removal of the ballast resistor right?

Really you changed so much it could be anything, but assuming you are confident in your work, think about the things you didn't do as well.

Good Luck.

new premiers, assuming you did not install the chokes? retard timing-no kick back, strobe when running coming up!

if not, tickle until just a little gas escapes both carbs and while kicking must open throttle about half way in order to draw mixture into combustion chambers - biggest mistake in my experience is not opening throttle with no choke

1up3down said:

new premiers, assuming you did not install the chokes? retard timing-no kick back, strobe when running coming up!

if not, tickle until just a little gas escapes both carbs and while kicking must open throttle about half way in order to draw mixture into combustion chambers - biggest mistake in my experience is not opening throttle with no choke

Click to expand...

My Amals (all my Mikunis & Keihins too) are different, they all depend on vacuum to pull the extra fuel in to start, respond best (cold engine) to a closed throttle. YMMV :mrgreen:


Flood the engine till you wet a plug. Most times it'll start just before you get there.

A simple thing but something that gets overlooked especially on a motor that has been sitting is dry cylinders. The oil eventually drains away leaving you with little to no compression. Squirt some oil down the sparkplug holes and kick it a bunch to spread a good coating of oil around. I just went through a similar issue with a Honda single that had been sitting for 4 years. I tried everything to get that bad boy running . I'd probably kicked it about 100 times in 106 degree heat prior to doing the oil trick. It started on the fourth kick.

Well, if it's kicking back, other than the over advanced ignition you clearly have everything there for it to start.
I would recommend you fit and use the chokes, as a reminder the chokes are on when the cable is slack. Try fitting clean or new plugs, reset the ignition, chokes on, open both taps, flood the carbs and try again with a little throttle.

best of luck,
Dave

I don't know which brand magnetic rotor you have, but there's not a lot of room to view the timing mark through the inspection port...



you wouldn't be the first person to mistake the "L" on the name lucas, OR the "raised edge" of the area where the timing mark is scribed onto the rotor, as the actual timing mark. (and then be baffled that everything checks out,.... but she just won't run)



It's just a shot in the dark, but worth checking again that you are using the correct timing mark, because that's what it sounds like from your discription.

If its kicking back, it is trying to start. Keep retarding the timing no matter what the marks say until it fires without kickback.
Jaydee

Commandos are an easy bike to start when you get the knack of them, but they are not Triumphs. I do not have a clue why your bike won't start but it may possibly be you. It took me a fair while to get into the way of it and it needs a fair boot and a bit of open throttle just as it fires with my Amals ,none with the mikuni. You sound like you know what you're doing so I'm sure you'll get on it soon enough.

There are numerous reports of simply swapping the trigger wires at the stator location "fixing" the problem of no start with several different brands of electronic ignitions. (black/white and black/yellow wires)

Use a digital voltmeter to make sure that there is at least 13 volts in the Li battery, preferably 14volts . Below 12.8 they go into limp mode and produce maybe 5 volts.

Glen

If you have a degree disc, confirm the timing marks on the rotor are accurate - it's caught me out in the past, and as others have observed, it's clearly igniting mixture but at the wrong time.
Also remember the cam runs backwards