When Retardation is Smart

Discussion in 'Trials' started by motobene, Apr 6, 2014.

  1. motobene

    motobene Motoing for 44 years

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    Retarding the timing is a good trick to mellow a bike, make it easier to start, and less prone to stall. I found I was taking more points on my powerful 300 Raga, so I sought ways to mellow the engine, have the bike start easier, and be less prone to stall. Most of us prefer ‘sweet’ bikes over quick ones because the sweet ones don’t ‘bite’ us so quickly, and if you want radical things to happen fast, you can still spin up the flywheels and dump the clutch.
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    In the past you could remove the flywheel and rotate the whole stator plate to change timing. You’d mark the stock location, then retard or advance timing. The ignition pickup was on the slotted stator plate. Many modern bikes have a fixed stator plate and the ignition pickup external to the flywheel (under the flywheel cover bulge), with a milled relief on the outside of the flywheel to provide the ignition trigger point. The new setup is simpler, as there is no timing to set. It just assembles one way. The pickup is fixed to the case with two screws. You can get some timing flexibility simply by slotting the screw holes in the pickup plate. I don't need any more advance, so I only slot in the retard direction using a Dremel.
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    Here’s how on a Kokusan ignition bike, but it’s easy to generalize from there. Remove the flywheel so when you Dremel the holes in the pickup plate the steel shavings won’t stick to the pickup and the flywheel. Mark you stock timing position (punch the plate and case). Remove the pickup screws (mine has a post on left (7mm box end) and a 5mm cap screw (4mm hex) on right. Dremel the holes as shown in the photos.
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    On Betas with flywheel on the right side, the direction of retardation is still toward the front of the bike (with instead of against flywheel rotation).

    Kokusan setup on GasGas:

    [​IMG]

    The pickup modification:

    [​IMG]

    How much I moved mine:

    [​IMG]

    Modify and enjoy!
    #1
  2. motobene

    motobene Motoing for 44 years

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    Additional info:

    It's now very easy for me to change timing in the field. Don't worry about timing lights and all that because you can't mess this up. There's just not that much adjustment.

    I changed the right screw to a deeper head 4mm socket screw from the OEM low-head-height screw, which is lighter but too easy to strip (mine was OEM, assembled dry, stuck, and had to be chiselled loose. The left fastener is a 5mm thread stud, which double as one of the plastic cover screw threads. It helps to modify a 7mm open-end wrench because the flywheel is so close to the stud. Modified means the outside edges of the wrench head are ground so you can turn more degress on the 4-sided milled flats of the stud. Grease these two threads and don't over torque them, and you'll have easy timing changes with only a removal of the shifter and flywheel cover.

    One surprise I got was my idle didn't fall noticeably after close to 2.5 degrees of retardation. I attibute this to the total amount of possible retardation, just under 3 degrees, not being all that much. Ikept the relatively high idle. I tried a low idle, but that made creeping up over small obstacles feel less secure regarding a stall. While stall tendency is much reduced, it's still smoother and more consistent when you set the idle to be healthy in first gear, clutch in, stopped.
    #2
  3. lineaway

    lineaway Long timer

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  4. motobene

    motobene Motoing for 44 years

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    Thanks. You're the one who prompted this mod, as you did it on your gasser related to the ignition module discussion. I think I went not quite as far as possible, when the stud hits up against the molded body of the pickup. I'll ride this way a while then if I feel like it go half way in between. The next event is a 2-day just SE of Amarillo in canyon country around 3,500 ft altitude (+2,000 ft for me), which may call for bit of the advance back.

    There are real tools for the ignition? :eek1 I just dug around and found an old rusty 6mm wrench and modified it on the belt sander:wink: It's 40 miles to town, so I make due with what I have.

    Anther thing besides taking more points with lots of power was watching smooth and skilled Rachel Hassler ride in Texas, then finding out she's on a Dellorto carbureted 250 and normally rides in the high country. Yeah, she's lighter than me, but I thought how most of us are riding bikes more powerful than is really good for us.
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  5. Rockcat

    Rockcat LDA

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    On my '56 BSA, this is adjustable on the fly. It's great to be able to decide how much advance you want for each section. They were doing this 60 years ago!
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  6. motorcyclemark

    motorcyclemark Been here awhile

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    I assume this same mod on the pick up can be done with the newer bikes that came with the Hidra electrics. Might be worth removing the S3 flywheel weight on my 13 280 and retard the timing instead. Stock did not care so much for the abrupt power off idle.
    #6
  7. 2feetdown

    2feetdown Been here awhile

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    Very interesting topic Ive got a new 14 300 race at first i thought it was too quick for me my old bike a 2012 300 race didnt seem quite as quick. I considered a heavier flywheel but now ive got used to the bike and it seems ok to me know. I did quit using type f and went too yamalube 0-30 and that seemed to slow clutch a bit. Im curious do you already have extra flywheel weight?
    #7
  8. motobene

    motobene Motoing for 44 years

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    I do not. That's something others have said I should do. I've ridden a bike with a weight and it does help. But adding more weight to the bike is not something I prefer, and I'd rather get there by other means.

    Interesting about the Yamalube. I should try that. The clutch felt a touch fast my 300. After retardation that tendency washed out, which was interesting. I have this uphill tight test corner that required precise slipping. Clutch a bit hyper before and now not so hyper. Perhaps it was somewhat psychological, as before I was a bit too afraid to lug because of fear of stalling. One input regarding spasticity of the clutch is higher rpm.
    #8
  9. motobene

    motobene Motoing for 44 years

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    You're like most of us. Even at a higher skill level a more gentle response right off idle is better for us most of the time.

    I bet the Hydra setup is nearly Identical to Kokusan given GasGas isn't incluned to change mount points and basic layout for a supplier change. So yes, the mod should work there too.

    Be interesting to know if you can get equal or better change with retardation than is provided by a flywheel weight?

    My 280, which is now perkier with the 300's ignition module, is going to get the retardation mod next.
    #9
  10. motobene

    motobene Motoing for 44 years

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    Ah yes! An accessible set a point on a plate. Loosen screws and rotate to change... refit cover?
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  11. Rockcat

    Rockcat LDA

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    There is a lever on the bars that is used to retard the ignition for starting without kickback. The lever and cable does the rotation for you. This was standard on these bikes and you can advance or retard your ignition on the fly without tools or stopping. I usually ride sections with the ignition retarded and go to full advance for big hills or any time it want full power.
    #11
  12. wilkinsonk

    wilkinsonk soup de grimace

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    I'm assuming just like the old Harley Davidson's. They had a lever on the bars to adjust advance to ease the kick starting. Mechanical points do have some advantages. I'm definately going to do this mod inside the Raga.

    Thanks Motobene.
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  13. motobene

    motobene Motoing for 44 years

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    You are welcome! If I get to it today after fitting a Factory Reiger to my 300 for the 2-day event this weekend SE of Amarillo, I'll report on the results of mellowing it too.
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  14. motobene

    motobene Motoing for 44 years

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    An update.

    I was super pleased with my now smoother and less powerful 2011 300 Raga. The settings I described above will be kept, event at altitude.

    I asked Ray Peters to ride my bike. It was fun watching him do steps and such. Compared to his 300 4-stroke Beta, he felt it was a bit too quick. Hmmm. I rode his 300 and yes, it was not as quick. But to me, compared to what it was, my Raga is now a sleepy pussy cat.

    I also exchanged bikes with a woman with a new GasGas TXT300 with Dell'Orto carb. She said my bike felt powerful and quick. That surprised me. I rode hers and it felt a little mellower than mine in stock form. Hmmm.

    Some of that mellow impression was the stiffer Dell'Orto throttle slide return spring and a dry and sticky throttle pipe, but riding that TXT 300 made me realize just how different individual bikes can be. It felt like her bike had a different ignition advance than my Raga's original (if felt more like the map in the Econo module). I am again reinforced in thinking there is more to these ignition maps in the role of how bikes run than might be assumed. It reminded me too that if you want to tame a bike, one other means is a stiffer slide spring! It does more than you think because it modifies the wrist proprioception signal to the brain.

    Anyway, whatever suggestions I make on settings should be viewed in context of your individual bike and preferences. There is no absolute scale for modifications.

    I did have one stall on Saturday, even with the retarded motor. It took me totally by surprise and it cost me the win by 2 points. It was my fault. I was contemplating a next thing and had the rear brake on a bit too much strong going downhill. I was fooled by the slick conditions rolling forward with the rear wheel sliding a bit. The clutch was just a touch too far out, the idle a wee bit low, and it was ptuh!, a foot down, and a very stunned brain followed by the incredulous cry of, "That's just not possible!"

    Oh, but it certainly was!
    #14
  15. motobene

    motobene Motoing for 44 years

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    Update report.

    The 300 Raga continued really yummy running at the second 2-day event with retardation in place: the Sooner Cup 2-day. I had some trouble in two sections for 3rd Senior Expert Saturday, and got 2nd Sunday, though I was nipping at Mitch's heels for a while.

    One reason to retard a bike is to lessen stall potential. I had one unexplained stalls on Sunday, right when I rolled into a section on loop 2 that I was easily cleaning. What the...? That really messed up my otherwise great ride. I rode Mitch's 300 with flywheel weight, and it is a real smooth pussy cat. I also watched him ride section after section with low forward progress rate, in 2nd gear, with a stock-geared bike. Still don't know how you do that, Mitch, but apparently the flywheel weight is a plus.

    So... I'm thinking I will go ahead and install a flywheel weight. I've been reticent at adding any weight, but hey... if it reduces unexplained stalls from infrequent to zero, I'm for it. The added flywheel mass may require backing off on the degree of retardation. Let you all know when I do it.
    #15
  16. motobene

    motobene Motoing for 44 years

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    Last week I did this mod on the 280 Econo. It presently has the 2011 300 Raga Kokusan ECM, so it runs a bit more perky than before. I was concerned it was a bit too perky for a guest rider at the ranch (Dr. Joe for you NM riders), so I wallowed out the ignition pickup holes and retarded the thing as much as I could. We rode in the rain, and the mellowed response was pleasing to Dr. Joe. Here he is having some fun on a gravel mound:

    [​IMG]

    No shortage of power, that's for sure. Just a bit mellower, and that helped on the greasy rocks.

    I'm getting an S3 flywheel weight for my Raga. When I put it on I'm going to split the difference on the timing, going half way to full retardation.
    #16