Timing Curve

[Blackduck]

Is there a copy of the standard advance timing curve around? Have the composit curves from the Dyna
unit but seeking just the standard or interstate curves.
Have a problem with mine going to full advanced at high RPM.
Australian models have a throttle positioner switch that varies the advance over about half throttle,
retards it as the throttle is opened to full.
Mine is OK to about 75% but then goes back to full advanced. Does it with the positioner removed from the carbs as well.
Think I maybe up for a new ICM
Any thoughts appreciated.
Thanks Blackduck

[98valk]

http://timskelton.com/valkyrie/tech/trigger_wheel_plus_dyna3000.htm

[Ricky-D]

It has always been my feeling that ignition advance is tied to motor rpm. The higher rpm the more advance timing.  At low rpm there should be little advance.

So what you report, at least to me, seems to be correct and not out of normal running parameters.

***

[Robert]

If you do have the curves that Dynatek provided then curve one is factory. Not to mention you want full advance after 75% so this sounds normal. Also how are you measuring it? Tell us why you think there's a problem.

[Blackduck]

It maybe correct but that is a lot of advance at high RPM, more so when many reports say maximum advance for outright power is 26 degrees. Most timing curves reach a set point then flat line.
This does the same and with the throttle positioner winds back the timing as the throttle goes above approximately halfway, levels off for a bit but further throttle increase starts the timing advancing again up to around 38-40 degrees.
Have a noticable lack of power at the end of the drag strip, just will not pull above 100 MPH.
It is not consisent though as after a night on the strip with this problem the next day it pulled past 100 MPH effortlessly.
Damn frustrating.
I have a dial back timing light that you can check the amount of advance and have marked the timing cover with various points of advance.

[Slammer]

the timing at higher RPM's you will quickly lose HP. The first time I Dyno'd my bike years ago with just a 6 degree wheel the HP shot up at a steep angle peaked and dropped off after 5000 RPM. After installing a Dyna3000(grounded with trigger wheel) set on 7 I think it would climb to 100 plus HP and hold. I also found a difference on the road. With just the wheel I would level out at around 115-120 MPH but with the second setup it would run on up to 140+. I now run a 6% wheel and Dyna with a MSD box that will grould the box at whatever RPM I want so I start out with lots of low end advance and then the box grounds and it keeps on pulling.

Just my 1.5 cents
Dusty#3404 

[98valk]

the timing at higher RPM's you will quickly lose HP. The first time I Dyno'd my bike years ago with just a 6 degree wheel the HP shot up at a steep angle peaked and dropped off after 5000 RPM. After installing a Dyna3000(grounded with trigger wheel) set on 7 I think it would climb to 100 plus HP and hold. I also found a difference on the road. With just the wheel I would level out at around 115-120 MPH but with the second setup it would run on up to 140+. I now run a 6% wheel and Dyna with a MSD box that will grould the box at whatever RPM I want so I start out with lots of low end advance and then the box grounds and it keeps on pulling.

Just my 1.5 cents
Dusty#3404  

what MSD box is this and part #, very interested.
Thanks

[Robert]

I don't know why Honda wants so much advance at the top end unless it is just a speed restriction but if you look at the curves including stock here the max is 30 deg with the stock icm. If you get a dyna maybe it will just bolt up and you can dial in what you like. I really liked mine but just couldn't keep it running. The curves you see are the dyna curves. If you do the interstate icm and a 4deg wheel then you will be just about where you want up till about 5500 rpm the max would be 33deg at 6300 rpm. You may be also able to do the ect mod and limit the advance to a couple of deg that would almost give you a flat 25deg from 1800 rpm.  Not great but not 40 and really you would be under 30 up till 6k. I don't know why the inconsistency with the speed even with the timing being what it is it should pull over 100 with ease. I really would like to find a alternative ignition system but haven't put a full effort in it, I'm sure you can adapt something to work that you can dial in the curves you want but the problem is the firing for 6 cylinders like there is really only 3. Im also not sure how accurate your dial back light will be. It calculates the amount of pulses and adjusts the delay of the flash by the amount of pulses. Well normally you hook to a spark plug wire and that wire on a car has one pulse per revolution our bikes have 2 so theirs quite a difference. this may be where you are having a problem with the amount of advance. If you don't use the dial and use it like a regular light then you should be OK because it doesn't calculate the spark  just flashes the light at every pulse. You will get 2 pulses but who cares at idle the marks will be on, but you will not be able to keep the crank mark on 0 when you rev it up by using the dial.

[Blackduck]

Good point about the number of firing times. Will double check the markings I have on the timing cover.
As per above what is the deal with the MSD box?
Had another go at this yesterday and also with an ICM of a 97.
Same lousy advance at high RPM. Think I can get around it modifying the timing wheel and the throttle positioner. With these Aussie bikes we do not really need the 4-6 degree wheels as they supply a lot of early advance. Need to plot the curve with and without the TPS and the TPS can be moved to change it's operating points. Possibilly a TPS off another vehicle may work, to damn expensive to just cut one up to see about reconfiguring its operation.
Think I will get a IS ICM and see how it works with the TPS.
Thanks for the input.
Blackduck

[Robert]

I didn't realize that yours are the bikes with tps you don't have to slice it apart just take a ohm meter and play with it a bit with each of the contacts. If it does control the curve I think I want one. You may have alot of possibilities to vary the timing that you may not know about. If the tps does adjust the timing then by adjusting it you may be able to dial in just exactly what you need. Most tps are of 2 kinds one is a variable resistor and one is just a on off switch. It should be pretty easy to find out what it does.

[Slammer]

to control when it grounds or get a dial controler that has several thousand RPM adjustment. You have to tap into the tach wire to pickup RPM's. Both pieces were around $150.00. If you do it and need help email me(slammerf6@cox.net) with your PH# and I will be happy to help.

Dusty

[Slammer]

but it has a wire that goes positive at the selected RPM for the light and a seperate wire that goes to ground at the same time.

[Blackduck]

The TPS is variable, 3 wire, 1 with power. Yes have had a short play with the multi meter and see some possiblilities. Not sure of all the countries that had TPS My manual only covers about half the world models.
Have a IS ICM coming and will then have another play.
The MSD system may also help with what I wish to achieve.
Will post after I get it sorted.