Topic: Dyna S Ignition Rotor not "free to rotate"

[grandelatte]

Hi,

I am installing Dyna S ignition onto CB750K1.  I am stuck at step #8 of the instruction.  It tells me to "Reinstall the hex washer and 10mm nut and tighten.  Ensure that the rotor is still free to rotate."  When I tighten the 10mm nut, the rotor will NOT rotate.  It is too tight. 

Can someone help me?  How can I tighten the 10mm nut and still have freely moving rotor???

Dyna S Installation Instruction
http://www.dynaonline.com/skins/downloads/instruct/DS1-1_1-2.pdf

TIA

Jim

[gane]

Jim, When installing a Dyna ign, the "points cam" of original ign's advance unit is replaced w/a weighted magnet. which I'm sure you  are  aware of.  This "bit", should  be shorter than the post it pivots on. and be located by advance arms. installation of "keyed" nut and retaining nut. should result in @ .30" of end play at reluctor. Advance unit should be soilidly affixed to crank at this point, with spring damped motion of cam. if not, double check placement at 'arms /base", & or measure relitive post/reluctor depths. luck G

[Spanner 1]

+1 with gane...must use the Dyna rotor, but I want to know why you are replacing the point ign. on a K1 ? Just wondered what advantage
it might achieve ??..... ( any stats or proof of better performance ? ).....Yes, I'm not a fan of Dyna S....!!

[Gordon]

but I want to know why you are replacing the point ign. on a K1 ? Just wondered what advantage
it might achieve ??..... ( any stats or proof of better performance ? ).....Yes, I'm not a fan of Dyna S....!!

Well, on my K1 the Dyna makes for much, much easier cold starting and a smoother, lower idle.  Plus I don't ever have to deal with setting the timing and gap again.  Did more than enough of that on the other old bikes and old VW I've had, and don't feel the need to ever do it again. 

Sorry, though, I don't have any "stats or proof of better performance", just my own knowledge that it works better for me than the stock set-up on the four bikes that I've had a Dyna-s on, and that's good enough for me. 

[Deltarider]

Best way to check whether an electronic ignition gives any advantage or not, is to compare the systems, without changing the sparkplugs at the same time. Most people I know that went electronic, installed new plugs as well. No wonder the engine ran better than before. I'm always impressed the difference new plugs make.
BTW, I run a simple selfbuilt transistor ignition, that saves my points. What I understand from the process that takes place in the combustionchambers (firing followed by burning)I believe there's nothing more to gain.

[andy750]

but I want to know why you are replacing the point ign. on a K1 ? Just wondered what advantage
it might achieve ??..... ( any stats or proof of better performance ? ).....Yes, I'm not a fan of Dyna S....!!

Well, on my K1 the Dyna makes for much, much easier cold starting and a smoother, lower idle.  Plus I don't ever have to deal with setting the timing and gap again.  Did more than enough of that on the other old bikes and old VW I've had, and don't feel the need to ever do it again. 

Sorry, though, I don't have any "stats or proof of better performance", just my own knowledge that it works better for me than the stock set-up on the four bikes that I've had a Dyna-s on, and that's good enough for me. 

I agree with Gordon. Had my Dyna S on my K4 now for the last 40,000 miles. Trouble-free operation. Same story on my K2. Would buy again tomorrow.

And Deltarider makes a good point.

To each is own...

cheers
Andy

[grandelatte]

Thanks for this great discussion.  This is my first cb750, and it will be used for commuting (62 miles a day) and as my first choice of transportation.  As I study more and more online, i decided to go with updated ignition system for its reliability and for the ease of maintenance, not for the power.   

Jim, When installing a Dyna ign, the "points cam" of original ign's advance unit is replaced w/a weighted magnet. which I'm sure you  are  aware of. 

Yes, it's the black plastic/nylon round "thingy".  It's in there.  That is "supposed to" rotate (move) freely.

This "bit", should  be shorter than the post it pivots on. and be located by advance arms. installation of "keyed" nut and retaining nut. should result in @ .30" of end play at reluctor. Advance unit should be soilidly affixed to crank at this point, with spring damped motion of cam. if not, double check placement at 'arms /base", & or measure relitive post/reluctor depths. luck G

If I had to shorten the "black rotor", would you shorten the front side (where the "keyed" hex nut sits) or the back side (the engine side)?     I guess I would use #60 or #100 sand paper to achieve this .30 gap.   

[george]

I installed the Dyna system, coils and ignition almost 2 years ago with no probs and nothing but praise. I just pulled my cover and shot a few pics, maybe will be helpfull, does sound like the magnet is too thick or possibly a spacer ?
Good Luck, if you still have issues PM me and you can swing by and look at my K8, I am near Katy.
George

Sorry my pics are horrible, but again I had absolutely no probs with this install .

[Gordon]

I'm not sure what they mean by "free to rotate".  If it were free to rotate it wouldn't work because you wouldn't be able to set the timing and have it stay set. 

If you can't move it at all then there's a problem most likely with your advance mechanism.  You should be able to rotate it clockwise a little ways to simulate full advance, but it should not "rotate freely" as it were.  I'm guessing this is what they mean when they that. 

[754]

loosen bolt, turn advance base till pin falls into its hole, THEN assemble...

[grandelatte]

Thank you all,

if you still have issues PM me and you can swing by and look at my K8, I am near Katy.

George, I will remember that.  Thanks.   

If you can't move it at all then there's a problem most likely with your advance mechanism.  You should be able to rotate it clockwise a little ways to simulate full advance, but it should not "rotate freely" as it were. 

You are correct.  It should not freely ROTATE, but move as the advancer pieces move and get retracted by the springs.  Right now, it is so tight, it does not move AT ALL.   

loosen bolt, turn advance base till pin falls into its hole, THEN assemble...

Yup, that is done already.  the advancer pieces need to be moved one by one to get them opened so that the black rotor will fall into the place.  once in place you should be able to rotate it clockwise for a bit.  then the spring should bring the rotor back to its place.  but with the 10mm nut in its place, this is not working.   

[754]

I have not seen this piece, I assume there are two grooves or slots for the advancer ears to fit in place... examine that area carefully for burrs or flash...

[grandelatte]

Thanks to all of you who commented.  I got it going. 

There was a spacer at the very bottom of the advancer mechanism.  I took it out and now it is freely rotating.


It's time to set the timing.