My Spitfire kicks back as a stock 650, now as a 892 ccm the same problem....
The engine uses commando crank, therefor 30 degrees ignition.
Have tried 2 different Boyer, and now a Panzon ignition. Still kicks back bad. So bad that the cotter pin in the kick arm regularly gets broken. (The cotter pin with threads on to secure the kick arm to the kick shaft.) Very strange.......voltage is 13 volt at the ignition module.
The ignition is set to 30 degrees. Mixture is not weak.
To me it sounds like it's timing is to advance. Are You running high compression pistons?
Compression is 9:1, Ignition is right, I have used strob to control that I have 30 degrees. The bike runs good on idle (runs on 800 r/min) and also good acceleration and good on high rev ( have tried to 6000 r/min), it's just the kick starting that is a real hassle. I have now 30 degrees advance as I have a 892 ccm with commando crank, before as a 650 ccm I used the regular 34 degrees.
If I understand right, kick back comes from the engine changes direction, and fire in reverse. As I wrote above the return kick is so hard and happens so regularly on all starting attempts, so after a while, the the cotter gets deformed (softer metal) and then it's almost impossible to remove the cotter, yesterday I tried using a hammer to prise it out, with no succsess , finally I had to use grinder and drill to grind out the cotter pin. I have seen other start spitfires by standing on the ground with one foot and the other on the kick arm. That would be unthinkable on mine. Have to put the bike on the central Stand and stand on the bike with the left foot on the left footrest, using the right foot on the kick arm carefully ready for return kick as I kicks down...... To leave the bike on the side stand for kick start would be untinkable .....Has been like this for years, also as a 650... It's a mystery to me.....What can I have overseen ?
I have an 850 Commando timed to 31 advance with a Boyer Digital which has idle stabilisation, on first kick of the day it kicks back but I suspect that is due to low battery voltage, all subsequent kicks during the day are fine. Advance curves do vary between even 2 identical boxes but I doubt that 3 boxes in a row would have curves with advance at low revs so it sounds like a tuning carb issue to me.
I would have thought your BSA would require more advance than a standard 650.The flame has further to travel,with a bigger bore size.
I don't think this is a case of having too much initial advance.According to the Pazon specs for a BSA advance curve,you would have minus 5 degrees at zero rpm and about minus 1 degree at 300 rpm cranking speed.The engine is already firing after TDC at start-up.
I've started Triumphs with the timing locked at 35 degrees.35 degrees at start-up and no advance curve.They don't give much trouble,unless you open the throttle too far at start-up.
I think something is causing a stray spark,which is badly timed.An intermittent voltage drop,like a bad ignition switch,might cause this.Maybe if you check the timing at cranking speed,you might find something is not right.
Thanks for opinions, I will try again to check the carburettor, and also look for electrical faults.... Im really confused on this one.
else the bike runs good, had a good run yesterday, the speed, acceleration and sound is for me enjoyable
I just have to sort out this kick back....
With the long stroke of a Norton it really pays to treat it as a single, position the engine with pistons going down on the first stroke.
Had a friend with a Norton which kicked back badly with a Boyer, but not with points.
My experience with my A65 has been similar with both Boyer and Pazon, the first kick often kicks back, but not after that. Perhaps since the box is not on until motion is detected the act of turning on produces an early spark? I never had any trouble with kick back with a Rita, which is on as soon as the key is turned.
In any case, it helps to have the idle mixture correct and don't open the throttle at all.
I don't run that much advance, probably 28deg. Starting with mikunies I put the chokes on and kick through 1 compression each cyl, unless its very cold weather 2 each, all with ign off, then I turn chokes off, ign on, no throttle and kick. It usually starts. Bumping it down a hill is easier, just put chokes on, ign on and go.
You need less adv because of the long stroke, maybe you could measure how far down the bore the piston is at 30deg, I doubt its the same as with the short stroke, plus the combustion chamber is good esp big bore, so it requires less adv to go best.
Thanks Mark, I'll have to try that. The Mikunis seem to make cold starting somewhat of a mystery. One kick once the engine is warm, though.
I try 28 tomorrow.
The kick back is something I had before too, same issue as a 650 engine. I really dont know whats causing it. As I have tried 2 different Boyers and now a Panzon, I guess the reason must lie somewhere else.
I dont understand your question Allan, how I did get to my timing mark.....?
SRM adviced me for 30 degrees.
If your battery is being charged with a voltage of 14.4v, then that sounds about right, I dont think your battery will boil with this voltage.
Since you have a high output alternator of 180w, IM wondering what kind of rectifier/voltage regulator you have? Hopefully you are not using a single zenor diode as this will probably fail with the high output from your alternator and cause elecrical problems. Modern solid state rectifers/voltage regulator units are much more reliable than the zenor and rectifier combination.
I would check the voltage at the electronic ignition terminals. You may find its different to the battery voltage which may cause the ignition unit to fire inconsistently. Also worth checking you have good earth connctions between the engine and battery.
If you are still getting kick back then really your only option is to retard the ignition until it stops. Kick back is a sign that the spark is happening before the piston has a chance to reach TDC, causing premature ignition and forcing the piston back in the reverse direction.
Well, seems like the battery was not the problem.....I still have kick back. Have tried to connect a external sound car battery to only the coil and ignitionmodule, The engine kick back still...same problem. Does this modules form Panzon and Boyer Brandsen work like on fully retarded (30 degrees)normally , and advance ( close to zero) when it gets signal in at tickover ? Or oposite way like its fires at zero degrees until it gets a signal about the revolution in ?
Most of the engine is changed and I still have the problem....for me it seems like nothing is wrong with the electronic ignition module, beavuse i have had the same problem on t modules, 2 from boyer. Brandsen, and now on the Panzon......
Usually it fires on the first cylinder ( any of the two). And if I dont kick really really hard, and firm, it will fie too early on the second cylinder, and the engine reverse rotation direction ( kick back)..
Any help , or advice ?
Here is what I would do:
1. Install a degree wheel or put marks on your alternator in 10 degree increments and TDC.
2. Remove your spark plugs
3. Watch your timing marks with a strobe
4. Either have someone kick the bike over or put it on some starter rollers (sometimes these have come in as a useful diagnostic tool for me)
It should fire very close to TDC. If it is not firing close to TDC, something is wrong with your ignition like reversed stator leads.
If it is retarding correctly, you may have to alter your starting drill. This is basically like starting a 500 cc single without a compression release. High-compression big singles will punish you if you try to start them like a twin. You HAVE to use the flywheel to get through compression. If you don't, they will either stop or kick back.
Retarding the ignition more may help. A digital programmable ignition may be necessary to get you the necessary advance curve for starting and running.
Something I found with mine after I rebuilt it. It had a real vicious kickback which would leave you hopping round the garage.
The draw effect on the carbs meant that I had to drop my slides to almost as low as they would go. This improved the problem, I then dropped the float height and this almost ironed out the problem completely.
Thank you Allan And Alex.
1. I had the same problem with this engine with stock A65 crank, as I now have with the Commando crank in this engine
2. have tried 2 boyer and now Panzon (same problem all the time). all comes as compleate ignitionset, with coils, plug cabler etc..
3. engine was before 650ccm, now iths 892 cc, (same problem)
4. engine has always been around 9:1
The thing is that it fires on the first cylinder, but then kicks back on the second. It behaves like it was a very high compression engine (I have 9 to 1 ) or with an extreme lightened flywheel (I have stock flywheel).
I have to kick in a way so that I always have the knee bent to be able to protect my foot against the kick back.
I have marks on the stator and rotor, when I turn the engine round without plugs, and use the strobe, I can see the marker at zero degrees... !!! when the engine passes 4000 r/min I have 30 degrees.
I have tried today to connect a car battery and disconect all other electricity on the bike, only coil and ignitionmodule had electricity. 13 volt. still same problem.
One of two happens:
fires on the first cylinder, and kick back on the other,
or it starts (if I use a firm long kick its starting, but its a bit dangerous to use to long push because if its not starting it will give a nasty kick back from the bottom of the travel of the kickarm.
Since you have already exhaustively checked your timing, what about your fuel priming/choking etc.? My current engines are 11/1 and 12/1 respectively and both require quite a bit of fuel in the chamber, especially when cold, to fire up without a nasty bit of kicking. The one bike has Mikuni's and they happen to have pretty big choke jets. I flip on the chokes kick a couple of times and then turn on ign. and it starts. After a couple of seconds off go the chokes. The other one has GP's and they need to be ticked heartily and, if the weather is cold (under 40f), I squirt a bit of carb cleaner in each. High compression, GP carbs, plenty of fuel, boom! PRT
I think it may be time to think outside the box. Try starting it with one plug wire disconnected. Take it over TDC on the working cylinder and down to where the exhaust valve starts to opens... feel that resistance. Then with the throttle only slightly cracked and well tickled kick it hard like starting a big single. Make sure you kick to the bottom so the kicker disengages. See what happens. This will verify if it is the second cylinder that is kicking back (I believe it is) I have had kickback on my b50 (10:1 compression)when the timing is too advanced of when you do not kick it fast enough for inertia to carry it thru the next compression. It shouldn't be a problem with a twin as a cylinder fires every 360 degree where it is 720 degrees on a single.
As second thought: Is the kicker somehow geared differently where you are not getting the rotation you need.
A third thought: Because it kicks back are you being timid now? I always kick hard and straight through. No pussyfooting it and no bent knee.
Thank you mr Mike, good points...
I will try to take out one plug and start on the other cylinder.
The carburettors is not the problem,, I have had several Amals Concentrics 32 mm before, and the problem was still there, now Mikunis flatslides 36 mm and still the same problem.
yes Im getting a bit pussy when kicking, because of the nasty kickbacks....
The kick dont disengage in the bottom, BSA A65 is not constructed that way, unfortunately..... I can not push all the way down and stand on the kick pedal, It will eventually kick back back and send me to the hospital..
The gearing of the kicker is not a issu eighter as I had th eproblem before as a 650 and now as a 892. I used chain primary before, now belt that has 10 higher conversion factor, but not the issue.
Only thing I think about now is to put on the original point ignition system, and see if it cures the problem. Also wondering if I had and have higher comression than I assumed, and that might be the reason for kickback.... I defenitely dont have over 10:1 incomression
very strange this issue,, really a nut.
Only thing I think about now is to put on the original point ignition system, and see if it cures the problem.
That might help, though I can't say why. A friend of mine had a '73 750 Commando which had a nasty habit of kicking back, but only with the Boyer installed. Put points in it and the problem went away. He always treated it as a big single, prodding the engine past TDC before kicking.
The only theory I have is that the Boyer is off until it detects enough rotation from the rotor. I think that maybe the thing turns on and sparks whether it's the right time or not.
My A65 only does it occasionally.
BTW: I agree with Tom on his starting procedure. I open the enrichers on the Mikunis and kick a couple of time with the key off. Turn the key on and she fires right up.
I think it might be good for you to describe your entire starting procedure, like from the point where you walk up to the bike. What do you do first, second, last. Do you tickle the carbs? How much throttle? etc.
Maybe post a video if you can. It's hard for me to imagine that bad of a kickback issue with the stock crank (can't speak for Commando crank) and boyer, if properly set up. At least not to the point where it beats up the lever pin.
The Boyer and Pazon both have a sleep feature, leave the ignition on with the engine not running and the box will turn itself off to protect itself. In order to turn it back on the Boyer waits for a new signal from the magnets, it will then turn on so you lose 180 degrees of crank movement before you get a spark, the pazon waits for 2 signals showing the crank is turning at a minimum of 200 rpm, so you lose 360 degrees. The Pazon uses the gap between the 2 signals to work out if 200 rpm is being exceeded or not.
I first came across this problem on a B50, it would start with the Pazon only on rollers not with a kick start, refitted with a boyer box and it started on the kick. Pazon recognised the problem and supplied a new LS marked box with a longer wait before sleep time, so you had enough time to turn the ignition on, tickle the carb etc before kicking.
But even the boyer will cause problems if asleep, so the cure is to do all the start up drill and then only when ready to kick do you turn the ignition on.
Very interesting Kommando, as Johnny Carson used to say "I did not know that".
I had exactly the same problem with my B50.
Would start on rollers but kickstart?--no way.
I had fitted a Pazon and after talking to Andy at Pazon they supplied me with a new "Long Wait" box.
Must admit I have never come across this problem on a twin and I have fitted quite a few Pazons to Triumph and BSA twins.
But I guess a big engine newly rebuilt so quite tight could give a similar problem.
And you are talking of a big bore A65--almost 2 X B50s!