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Post by wayne on Apr 16, 2012 3:05:05 GMT -5
***I'll modify this thread and this first post in case people don't read the full thing.***
The bottom line here is that there may be a difference between static and dynamic timing readings, but static is the way to go. Use a strobe to check advance. ------------------------------------------------------------------------------------------------------------------------------------------
I've been using 12v light bulbs and in the distant past, even cigarette paper to do the ignition timing on farm vehicles and the like.
I use the strobe when I have time but have never compared one to the other.
I have used the 12 v bulb on the RE5 for a quick and dirty static ignition timing. I tested this recently. A static time on the RE5 using a bulb and taking all the care in the world resulted in ignition anywhere between 5 and 7 degrees further advanced than you think. Setting 8 degrees static showed 14 degrees with a strobe light. No wonder my idle was so horrible.
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Post by HGH 770N on Apr 16, 2012 3:14:20 GMT -5
I will check that, My bike has always run better at 5 degrees on a static test , when i set it at 10 degrees it runs as you say with a uneaven idle. I will stobe it and tet you know. Rog
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Post by bdalameda on Apr 16, 2012 11:18:56 GMT -5
Why even use a light - Just take the plug out and lay it on the engine - you can then turn the engine with the alternator nut and when the points open the plug will spark and make a loud snap. This is how it was taught at the Suzuki Rotary school. One thing to look out for however - the screws should be snugged that hold the ignition points housing (distributor) in place when you check the timing as the timing will change when the bolts are tightened.
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Post by wayne on Apr 16, 2012 18:13:42 GMT -5
Indeed, any reading with the bolts not snug is completely invalid.
I'll have a play with the plug. Even easier if you simply use a spare plug. I've got another bike that was statically tuned so I'll see what the real setting is using a spare plug.
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Post by wayne on Apr 16, 2012 20:06:43 GMT -5
Now I'm confused.
I checked another bike which was static set using the 12v bulb method at 10 degrees. I then used the plug method endorsed by Suzuki and it came up with slightly more than 9 degrees. Not bad so far.
Next I put the strobe light on and found the same as the two other bikes I checked. Timing at idle via the strobe showed 14 degrees. Five degrees more advanced than the static method.
I imagine that the strobe setting must be the final authority (?).
Time to get Jess's ignition off the shelf and be done with the points.
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Post by goandy on Apr 16, 2012 21:06:43 GMT -5
You might have weak springs in the dizzy/points mechanism weights giving you too much advance at idle as the assembly spins? If this is the case then Jess's electronic ignition won't help much as it will still over advance too early. Anyone got a nos dizzy/points setup who can plot the advance vs rpm as a baseline?
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Post by wayne on Apr 16, 2012 22:13:15 GMT -5
Okay, that's an interesting explanation. I've now checked 3 bikes and they are consistently coming up with this discrepancy.
Could all 3 have weak springs (possibly) ?
Two bikes are well used, one with 34,000 klm, the other with possibly a lot more but the third has only 8,000 klm on it. Across all three the discrepancy is reliably the same.
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Post by goandy on Apr 16, 2012 23:31:39 GMT -5
Well maybe the advance at idle is normal? Set the static as described and that should be it?
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Post by wayne on Apr 17, 2012 0:32:17 GMT -5
Things get more and more interesting. Advance at idle could be normal and that'd be it.
The book actually uses a static system to set the points, so I answer my own question as to what's the final authority. However, I note that the book also intimates that the advance should start at 1400 rpm (amended to 1800) and stop at 5000 rpm (amended to 5800). It's starting to get complicated because of all the spring weight changes and options that occured over time. It'll take some research to work out what rpm applies to the beginning of the advance.
However, I'm showing the advance at idle rpm's lower than 1400...........hmmm.
I think that I'll go with your last suggestion Andy. I'll do a static set using Dan's (Suzuki) method and use 5 degrees until I can work this out further.
And before I leave it, I'm bothering with all of this because, while the bike is very tolerant of ignition settings, they do run a little differently between the factory 5 and 10 degree options.
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Post by goandy on Apr 17, 2012 0:45:30 GMT -5
I also found on mine that the woodruff key had worn and there was around 5-10 degrees slop in my dizzy drive gear......... That will of course be getting fixed!
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Post by wayne on Apr 17, 2012 1:18:37 GMT -5
Lucky they are tolerant of ignition timing !
As for my horrible idle, I'm going to have to find some other reason.
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Post by ziggystardust on Apr 17, 2012 6:33:52 GMT -5
I use the same method as bdalameda, quick and easy.
If I set the tick over speed correctly to the book it does sound different to other bikes as it should and that it may stall although it never has, I set it a little faster as it sounds and feels better.
Z
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Post by goandy on Apr 17, 2012 6:47:23 GMT -5
They are supposed to have a bit of a lope at idle- characteristic of the peripheral ports in the motor. Ever heard a worked Mazda rotary going brap brap brap?
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Post by ziggystardust on Apr 17, 2012 7:20:34 GMT -5
I know, it's just personal choice.
Z
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Post by kettle738 on Apr 17, 2012 8:19:36 GMT -5
I agree that this sounds like weak springs on the advance retard allowing the bob weights to spin out prematurely.
This early advance was a common problem on Honda CB450 Black Bombers; it destroys the idle and low speed running, and advancer springs were not obtainable seperately. The time honoured (cheap) fix in that instance was to bend the spring tabs on the advancer to remove the slack and put a little pre load on the springs.
Not having looked at the RE5 unit.....is that a possible route? Failing that, another cure was to fit new advancer springs from a different bike that were available. (Yamaha XS650 I think)
Mick.........kettle738
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