Timing Advancement - Who dunnit?

[truthfriend7]

Well reading the thread "speaking of speed I broke 83" I decided to give the timing advancement a try. I moved the key up a few mm. down a few mm. down a few more mm. and finally way down about 10mm (this was done by filing out the holes where the arrows are in the second pic). I cannot tell any noticable difference. I would say that down was better than up, but it didn't help my top speed. Knothead said it helped him out considerably. Has anyone else tried this? What were your results? Did I do something wrong?

[ob1]

By filing the holes, all you have done is adjust the base level timing. Your CDI box still has whatever advance curve is programmed into it, modding the pick-up coil only changes the starting point which the CDI works from.

Assuming your bike is completely stock, you should first open up the intake and exhaust {air box openings, air filter, muffler, header welds} Wanna get even more? Port-match the intake and exhaust, smooth the intake port and polish the exhaust port. Little more, cam time.

Then, adjust the carb through size and jetting to get some more power.

Then, an aftermarket CDI with a more aggressive advance curve, followed by final carb jetting and tweaks.

Tweaking any motor to peak performance is not a single mod, but the combined effects of multiple mods.

[knothead]

Originally Posted by truthfriend7

Well reading the thread "speaking of speed I broke 83" I decided to give the timing advancement a try. I moved the key up a few mm. down a few mm. down a few more mm. and finally way down about 10mm (this was done by filing out the holes where the arrows are in the second pic). I cannot tell any noticable difference. I would say that down was better than up, but it didn't help my top speed. Knothead said it helped him out considerably. Has anyone else tried this? What were your results? Did I do something wrong?

Wow, moving the pickup 10mm either way should have been enough to make the engine run like crap. Or at least start pinging.
I don't know what's up, you're the second person who said they tried this and got nothing. But it made a difference on mine and it made a big difference on a friend's Honda Rebel 250... I think there was another on here that did it to an ATV with good results.
Err, I never can remember up or down, to advance move the pickup opposite the direction of engine rotation.
The only thing I can find that might be different on my bike is that I think it has a 27mm carb and I think most others have a 29 or 30mm. But a smaller carb should hurt upper RPM power. So I don't know what's up. It happened to me by accident and I worked backwards to find out why the bike ran better.

[PorterzCustomz]

You took all of that off for nothing, all you have to do is plug in a new CDI box with timing advance. My bike barely breaks a sweat at 80+ with mine. And for the haters that think its fake the video is going up in the next few days so your all going to look like a bunch of morons when you see it on tape.

[knothead]

My take is that the bikes are set to run lean from the factory, running lean increases NOX emissions and to combat that, they retard the timing. But that means the potential for more power is there and close at hand. I'm just guessing and have nothing to back that up. Before I messed with mine, I absolutely couldn't get past 7000 rpm in 5th gear. After, I did run up around 80 about three times, after the last time the bike was starting to sound bad (thought I'd done some damage, way too many R's) so I didn't do it again. Later I drilled three .5" holes in the muffler and that killed it, now it tops out about 70~72 mph (which is still too fast on this bike anyway! ). If I was really worried about it I'd try to sort it out... but I don't care too much, if I want to go fast I'll ride my TDM rather than mess around with a 200.

Originally Posted by ob1

By filing the holes, all you have done is adjust the base level timing. Your CDI box still has whatever advance curve is programmed into it, modding the pick-up coil only changes the starting point which the CDI works from.

Assuming your bike is completely stock, you should first open up the intake and exhaust {air box openings, air filter, muffler, header welds} Wanna get even more? Port-match the intake and exhaust, smooth the intake port and polish the exhaust port. Little more, cam time.

Then, adjust the carb through size and jetting to get some more power.

Then, an aftermarket CDI with a more aggressive advance curve, followed by final carb jetting and tweaks.

Tweaking any motor to peak performance is not a single mod, but the combined effects of multiple mods.

[DesertDog]

dont forget to adj the valves as well, i did mine 8 thous ex. and intake, going to do the timing next.

[truthfriend7]

Do you guys have any links on how to do the port/polish and where to get the cheapest CDI with advanced timing? Also any links on the cam adjustments would be good too.

I've already got a 115 jet, k&n filter and drilled exhaust.

[PorterzCustomz]

Originally Posted by truthfriend7

Do you guys have any links on how to do the port/polish and where to get the cheapest CDI with advanced timing? Also any links on the cam adjustments would be good too.

I've already got a 115 jet, k&n filter and drilled exhaust.

please see my magic box thread for the info. http://chinariders.net/modules.php?n...ghlight=#39337
My bike will go well over 80 with it installed, in fact I regularly see past 80 by accident when driving normally offhighway.

My valves or engine does not sound any different after holding 80+ its just a normal every day thing both on dirt and onroad. Before the box I was lucky to see 65 on a long straight!!

[truthfriend7]

Well I messed with the key a few more times today. I put it back closer to stock and put my cone filter back on. It's bogging a little bit. I think I need to check the jetting. I haven't been real impressed since I put on that 115 main jet. I might go back to stock.

Thanks again for you guy's input. I like CDI advance idea, but my bike is not worth an extra $50 to me right now. I thought the timing trick would work, but oh well, not all good things happen for free. If someone finds something I did wrong or a new free idea for top speed, please let me know.

[cresstt]

Dont you have to move it left or right in order to retard or advance the timing not up or down ?

[truthfriend7]

This is the link that I followed: http://www.dirtbikemods.com/mini_bik...ng_advance.php

I hope someone with more expirience will comment on what you just said. Moving it down made sense to me because I assumed there was a spot on the flywheel/magneto itself that initiated the signal to send the spark. My thought was moving it down would mean that the spot on the magneto would trigger the key early causeing an advanced spark.

Ok I'm spouting my ignorance here. Could some please comment on the previous post and also tell me if the big golden circle thing in my picture is the flywheel or magneto?

[cresstt]

to change the timing you need to move the pickup sensor vertically according to the green arrows on the below pic. The magneto rotor is moving anti clockwise and from what I see from the pic, in order to advance the timing you need to relocate the sensor further down in direction B so that the notch on the magneto will meet the pickup sensor earlier

click to supersize:

[truthfriend7]

Well, that's what I did. Can't tell hardly any difference. I'll check more of the jetting and maybe go back to stock jets. knothead said he drilled his exhaust (which made things worse) and has a smaller carb. Well, my exhaust is drilled too which may hinder this mod's effectiveness. But I can go back to my smaller main jet.

[katoranger]

It may be a difference in the CDI programmed curve. The lifan may use a different curve from a roketa etc.

Allen

[culcune]

If I'm not mistaken, Roketa's enduro engines are manufactured by Zongshen.