Mysterious quiter Trixie Combat working on a tan

Took Trix to work X-mass eve, left er idling to order breakfast while office heating up got on and got 200 ft then spit/spat missfire back fire then fire went out. Nothing obvious, gas fine, battery barked horn sharply, just no spark sense but one back fire puff of smoke. I was at 3500 ish rpm so no battery issue should be involved.
Wes rescued me then took us in a movie and got my last minute wife shopping done in a city. So a great day started on a Commando.

Plugs look good light pale tan down porcelains, dry sooty rims, thermal stain on hook about spot on for timing indicator. Gap .o23" to cleaned em and set .025" What ever went wrong did in in .5 second. R/R plugs as seen from seat.


Checked at home to find pts firing. RH/rear points oil crusted a bit so throwing more sparks out than the LH set, cleaned and wiped surfaces, no sanding thank you. Appear clean w/o burns or pits. So kicked over to get normal looking R & L gap snap sparks and even the plugs on head sparked mostly blue too. hm Put on charger just in case and tank in 33' F garage and kicked for no joy but a few surprise hard back fires. !!! Trix has never done that since first dialed in. AAU would idle back down with nicely after 20 sec delay so shouldn't be sticking open just kicking. Must double check that. So stumped what would cause back fire and not start. Will check static time light but not likely both points shifted after a fine ride in 34' F. Can't timing light em w/o starting first. ugh.

Car is tranny dead for over a week more so Trixie is it before I can barrow a car in a few days more. Need collective psychic help on this one. Off one more time before give up tonight.

Steve pull points plate and get some fresh light grease onto the AAU pivot pins and slot guide tracks. Reassemble.

Ok that's psychic enough for me to try. Did notice the little cam surface is dry running so had oiling on mind but ugh I bet I throw off the initial timing as usual.
For some fogged out reason I have not checked to push on AAU yet. Off to do that now and one more starting attempt before tool time tomorrow.

The most neglected part as the bobweights NEED regular greasing and no one wants to do (pulling pointsplate,re-gapping,re-timing)it then wear slots develop in the pin tracks ,hanging things up ,slower recovery and wear/timing advance/retard changes too. New those are real pricey but used in good shape plentifull.

L O G I C . gotta be something simple . . . .

Most Likely , the auto Advance units slipped on it taper ( the key bits often abysmal ) .

B U T . CHECK the TIMING , BEFORE You go further , so its not a stab in the dark .
Cover your options by Eliminateing , in order .please .

So , we get the cigarette paper in the points , push crank through to release . ( no getting fancy ) On the mainstand /
beercrate , in top , plugs out .

Drop the long scewdriver down th plug hole . If it goes w a y d o w n , shes SLIPPED . bother . GOOD .

as we know , fully retardeds near top dead centre , and we're not pushing the Adv. in at this stage . so . . .

( PS , been telling porkies BSA Adv. Unit ( 72 A65L ) is THIRTY degrees , marked ' 15 ' or course . oops )

So its not ' set it at 3/8 btdc , and chock Adv. fwd .
Thats next , or last , if youve had it slip , whip it out , strip , clean , lube . ( any Lucas thingo , the bits are liable to fit )
counter Wts & Springs .

Edgar Alan Poe stories . . . Darn Bonneville coughs , hiccups & stops .
Wot , Egad . the timings ' Slipped ' How Bizzare . ( yes read on .INDEED )
Roadside TIME THE MAGNETO , three times . Tow to Mates ,
spend half Christmass Eve re timeing Magneto . Six Times . BIZZARREEE .

The " 1948 " dated paxilon Auto Advance unit had stripped about three teeth .

Therefore NOTE : ' Be Methodical ' . :lol:

Not those hidieous 6V coils & ballast resistor , I HOPE .

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Id Eliminate The Wireing Loom . Disconect Batter , jury Rig Coils DIRECT to Battery . Thatll learn the bars. . . .

Then youve ONLY the ignition system to Deal To . er . with .

EAP again , hineous BSA ' Twist 'switch in Headlamp shell .A mate 'd told me to shoot him if he ever got like that .
I WAS SORELY TEMPTED > l o n g story . If theres a Stupid switch that looks like a starter button ( 50s )
grip grooves , shoot it ,
or add it to the pile with the 6 V coils .

Get a big hammer once youre done ( Fixed ) youll feel much better after .

THEN theres the condensors . The ones of the Chevy will do , seeing the Trans gone .
While your at it , Thats probly just the Oils Low . or someone forgot to adjust the bands .
Gotta have a cooler on a automatic , indeed .

( If theres a pre 1890 Chrysler in the woods , your a lucky man . Id be embarresed if a posche could hold a well sorted Chrysler . Grab It . NO tin worm , the rest bolts on . Older the better , All bits fit . 1960 to 1980 . WHY ,
there only Half Speed at 100 . All the super speedway stuffs under there . . .

That NORTON going Yet . Matt .

P.S. the dude at the roadworthy on the FAL Coon , left it idleing for a while .
all the grot coagulated and dropped square in the main jet .Talk about fart around sorting that one out . . . :lol:

Well Matt the AAU is all stuck up and dry as a bone but still either back fires with it advanced or no fire with it twisted to retard, so likely on kicking cam is draging the AAU to full advance, so nothing for it but put in the new AAU today. I've also got to retard my 20 hp genset magneto by opening the points from .013" to .015" as each .001 equals about 2' timing change. Rained then froze last pm but not 50' F and clear so fingers won't hurt to diddle the tools.

I found the problem, a swivel post of LH weight had broken off, alerted by the piece of post found behind the AAU. I've a like new AAU so in process of seeking fire again w/o a mystery anymore, just tedium.

Hey Hob,
interested to here you went wife shopping, ???
AC.

Stuck advanced and bar ends near knee , can be ' interesting ' . Limp.limp .

Good its sussed . Most dont appreciate the intricacies & nuaences of the old ignition systems , or there capeabilities
giveing ground for endless variation . WAS ' Bendix ' contact breakers , I think out of a Everude the poms found to be
suitable for pulling 10.000 + in the Triples , & used in the Daytona Commandos .Bolt ( screw ? ) straight in . Almost .

That funny white waterproof grease is the go on the Auro Advance . Litihum wheel bearing grease .

If you grab a Dingey , Trailer & Outboard , seeing its christmass , youll save heaps , as you can share spares & Lube . :mrgreen:

Hey hohoho, only took all day and night to get correct jug on correct stroke and timed to start. I'd stave as mechanic or go insane if I had to. Started in upper 30'sF after a few kicks to get flooded mixture combustable and responded like she should for couple seconds then shut down as rocker covers still off. No smoke at all in seal garage nor fire with exposed element heater and gas fumes to get hi on.

Once a wife shopper always a wife shopper, duh, if really a full male then pure pig through and through, even if not acting on it. Will ask current Sweet One Who Must Be Obeyed to hold throttle for timing light to diddle both contacts close to the mark on the fly.

Gee , first the Compliment on the first picture , The Plugs look pretty good .

Now , ciggarette papers in hand ! , Points set dead on whatever Gap , a strip of the ciggarette paper 1/ 4 wide through the c.b. contacts , put the crank on the indicator .

Twisting the points cam round with your best pair of needle nose pliers , slight tension on the paper . It Should FREE Just as the cam hits the Stop .

Hold a small screwdriver between the teeth to flick the points open to slip the end of the paper inbetween . Keep the papers dry .
A good day it it all goes ' spot on ' dead easy . Others bits of paper get stuck everywhere . :lol: Dunno how thick the paper is on a mike , of the size of the Gnats d's there .

Not a lot .

Mike the Cig Paper packet to , 5 thou & times three = 15 for Gap . Scissors work best , the rough edge torn is to Artisic .

Tally Ho rice papers,,,, not the other type with a wire in them or the licorish flavoured ones.

I rolled Trixie out in the sun in upper 30's but metal still in the upper over night 20s'F flooded a drool stepped on lever and got life and no smoke till some seconds later on blip ups then cleared to just smoke hints. Added back waisted head steady so can kick up heels a bit more on holiday cruise to work and back comfy 40's>50's.

Papers ok for road side and blottering up oil crust but each .001" of more gap = about 2 degree's retard timing and Cdo are pretty sensitive to that to start.

I set engine to 28" adv mark, mount the breaker plate centered in slots then with bolt in AAU held full adv I twist it till test light hooked to point spring and head just lights as point open and try to nail it down there and then kick over to light dims on and look at where alternator time mark lands and diddle new AAU postion till close enough I can didle the point plate and points nearly on same close mark. Test light comes on in other positions than just firing so bit confusing at 1st and 2nd and 3rd ...

The thermal stain on plug hooks should land right about the bend so will plug chop with new ones on a steel 1/2 mile hwy climb then shut off and coast back
to look/photo and diddle each point dead on as can. Trixie smoked so much intermittently on either side I expected to see oil fouling but nope just about right with beat up Amal fluted bores, #3 slides and race taper needles in mid groovy. Wasn't sure with the old AAU failing if electrical or carb issue to settle down idle quickly but now she come right back to stable purring. That will be nicer on the coast downs on THE Gravel as well as just sitting around with people enjoying the obsolete sound.

Mostly run 87-89 oct no booze gas but tank is low and timing close to 30' so will treat her to 91 oct out of over head farm tank before considering closer to 28". So far No Backfires. My perferred time method it adv til back fires then back off till just don't on Combats, then put a light on to give a number to it. Trixie is degree'd wheel indexed. I've been getting some early throttle up stumbles/hesitation working up gears so not sure if that's solved or more to refine. Not very often and only 1/3 second then fine. I do get sense of it holding WOT over 100 but hardly ever do that on Trixie 19T to find pattern to diagnosis.

Been stranded 3 days so off to paying work right now, chow.