How hard is it to kick start a 72 750 Roadster?

Does your bike have electronic ignition? Kickback is a known issue with Boyer ignition if the battery is anything less than fully charged. I have recently purchased a Motobatt battery which states that it gives additional charge for starting; and I have had a noticeable lack of kickback since then (and I use a trickle charger to ensure that the battery is fully charged before I attempt to start it.

Trixie's hand job was done on pure factory Combat, but only once to show off. Bow and then will kick my Combat off with just moccasins on, but only if she fires off on 1st or 3rd kick, then better put on boots or end up hurting. If some issue like battery not holding charge, I can wear myself down in a hand full or two of kicks, too tired to even ride right off safely - if it did happen to finally start.

Once you do it it to run, while doing nothing else to it, it seems to break a spell and they tend to easy start routinely afterwards, till something else prevents it, then diaganostic ritual to repeat till getting it right.

My buddy Wes has a routine of constant banter about all the fragile and hidden mysteries he's dealt with over the years, to point the evidence piles up to just let em sit, yet every time he's rolls up on his paired down '71 at my place, first words out "Man What A Machine"

Kool_Biker said:

Hi It's just so hard to give it a good kick (I weigh 76 Kg) and on occasion will kick back which frankly, is scary.

So I wonder if compression may be at fault here .

Click to expand...

Strong compression is GOOD sign. Kicking back is a BAD sign. What you need to look for and tell us - is what type / brand of ignition system is fitted? Coz, if its an old analogue Boyer, they are low voltage intolerant and next, the retard degree point is a tad too high for easy starting. Both effects can spoil starting.

An electronic ignition must be checked with a dynamic strobe timing light. If its zooming way over 30 degrees above 3,000 RPM its means its also showing the same amount of over advance from the static kickstart firing point. And as your leg is coming down and the piston going up the plug sparks too early and the bang pushes the piston back down which means your leg goes back up. Hurts. Yes.

Mick

Good points, expect kick back if low volts, loose wire almost anywhere, trigger wires broken inside or trigger wires reversed connected. Points have a grimlin in them called the Auto Advance Unit that is in-famous to wear and stick in advance for miserable starting and hit backs. Normal is for them to fire and out race your kick so don't really even have to kick, but its way more common to have to thrust through full compression like a krate kick through a chest wall.

All,
I am overwhelmed by your speedy response - in numbers, wisdom and encouragement!
I am not new to engines and everything you suggest makes sense.

Ignition is Boyer Bransden Micro-Digital - I understand this is as good as they get? I also have the Boyer Power-Box installed.
I have timed the engine both, statically and dynamically, but will re-check, take a go at it again. A little bit of retard until I re-build my confidence can't be a bad thing? Can you suggest a value? I have both a strobe and degree wheel.

Also the tip re battery in tip-top condition is news to me, I KNOW this will help going forward.

And what was this about the 850 kick starter being a few cm longer? Sounds like a good investment surely?

Thanks a lot again - great forum!!!
Aris

I think Dog T has it, the most important thing is a positive approach. If you kick it with the attitude that it IS going to start you will kick it with conviction,which is what is needed. I have a 920 with a Maney primary and on a cold frosty morning you cannot allow it to think its not going to start.The reward is when its running,there is nothing like a Commando is there! You can always tell a Commando owner by the limp...

If your Commando has the total seal rings this can make it a real pain to get it over top dead center, specially on a cold morning.
You could use the old racers trick that is putting her in gear and then pulling the bike back till she stops, this will put the piston some way after TDC so then you have advantage of the full swing when you kick, a similar effect to a decomp lever on the old singles.

If you have not degree wheeled the actual TDC mark, but just going by the Norton dial, some are over 10's off. I have learned my spark lesions the hard back fire or no start way, so with pensiveness I set to max adv per the model engine, then creep up/dn timing .5 degree at a time, so yes lots of trial/error- kick efforts, till it starts to hint a back fire, then retard just till it don't, nip up and riding into the wind on any octane available.

... and ... what about this on-going thread comparing Pazon over Boyer, especially the former's higher advance curve stability with a less than perfectly charged battery, amongst others ...

Aris

From what has been posted, Boyer stopped revising and perfecting their product. Pazon took the ball and ran with it and is now a superior product.

I bought my first Commando in 1971, I was 16 years old and weighed 98 pounds.
I now have my third Commando, I'm 57 years old and I'm 98 Kilos.
Funny that because I don't think I'm any taller.
I couldn't start my bike when I went to ride it home from the bike shop, in 71,
and the guy there had to start it for me. I soon learnt to start it because it was most imbarrassing
to have the KOOLEST bike in town but be too scared to turn it off when all my mates came to look.
I certainly think that higher type bars help, rather than to be leaning way forward, but 40 years later
and double the weight, I've got it covered now.
For a cold start, I always start up on the center stand, with a left leg kick, and let it warm up
while I get dressed. Warm start, conventional if I'm ready to go.
Timing spot on and good Carbs are the go.


AC.

The I.o.M. production racer kick starts , were about 12 feet long , so not a bad idea .
anything that gets the foot crank more inline with the mounting spline isnt a bad idea either .

Fixed advance isnt brilliant , as the kickbak can be unanswerable .But 28 or 29 fully advanced is where id go .
31 for going far faster , but they can be a little crankie and require the pilot on the job , not daydreaming . :lol:

The ' kick & stop' isnt unusual . Kicking up is indicative of something .

Position cylinders , then crank , then leap upward till legs straight .
Full weight on your right leg will swing it through nicely .
except on the odd occasion the advance is full forward .

Those gold & blak Velos were said to be the ankle breakers.Theyve got a short kickstart.
Whowever the shaft is square as is the fixing on the crank , rather than a spline .

COLD , pull the cylinders through twice before ' switches on ' .
and dont attack the leaver with your boot . Its Not a Kick Starter . :lol:

I never use the stand to start my Norton in all the 36 years of owning it, when you learn how to start it, it will come natural to you, I sit over my bike to start it one foot on the ground the other on the kickstart, make sure its just on compression then give it a good swing with the kick, once it has fired up I usaly sit on the seat to kick it over, anyone that hasn't owned a Norton will have troubles kick one over if they don't know the way to do it, all my friends have troubles kicking mine over and when they can't I just sit on it and give it one kick and it will start every time.

Ashley

When I got my first Commando a 72 Fastback in 1981 I probably weighed about 60kg, maybe less. That bike didn't have a centre stand so I started it on the side stand. Both that bike, and the one I have now, a 70 model, always started first or second kick, but as DogT says, you've got to show it who's boss or it will bite you. The only time this bike kicked back was after I fitted Boyer ignition, following the instructions for initial static timing. After limping for a few days I retarded the timing a bit - still correct as measured by strobe light - and it stopped kicking back. Ease it up on compression and then swing down with your weight behind it. Leg straight, follow through!

Something that helps me is to start the kick stroke with the lever part way down. That is, not with the kick start lever in the full upright position. That way you get more leverage on the kick start lever as the stroke begins and thus it is less likely to kick back.