Sure, but the advance curve is nothing more than what is added to static timing, right? He added a taller advance curve, not just a steeper one, so total timing from 5,000rpm up is most definitely effected by what he did.

To avoid getting into semantics, can I ask what your actual spark timing is from 5000rpm up? That is, at what crank angle is your spark event?

He did runs with timing at 15, 20 , 25, 30, 35, and 40 degrees BTDC at 5000rpm and up, and found no power on the table. Are you running more than that?

Hopefully RayCour will jump in here...

 

Maybe 15mm is just extra width across the rotor (side to side) to get the weld area away from the pickup?

So you're saying you did the mod for customers in Germany and just had them install the rotor with no key? Something to try on dyno day

Maybe JB Weld a 3mm piece of steel 2mm thick onto the rotor..

 

So you're saying you did the mod for customers in Germany and just had them install the rotor with no key?

No, I think he's saying if we want to try the timing out without a permanent welded mod to the rotor, we should pull the woodruff key and try advancing the rotor(and then tightening the snot out of it).

 

[QUOTE=Richard Avatar;510361]Maybe 15mm is just extra width across the rotor (side to side) to get the weld area away from the pickup?
yes

So you're saying you did the mod for customers in Germany and just had them install the rotor with no key? Something to try on dyno day

nope..thats why we welded it.. with key..ignition is fixed ,customer can't make a mistake, all safe.

and no need for a dyno to see if it works.. its not a "maybe there is more" thing, you feel it instantly..it just keeps going past 8000rpm

 

Someone do the mod and report back the results!

I wonder what this would do to reliability though. I have no doubt the stock motor has no problem coping with the increased power, but what about a bike that already has a 351 kit and cams installed? Would the engine be able to cope with all the extra power? We are talking 32hp+ at the wheel

Also makes me wonder if things function the same way in the EFI bike...something tells me it does Maybe I am hoping, lol.

 

I don't know why there is doubt...
if you check the parts out.. everything is the same from 92 to today. same camshafts, piston, head.. same compression.. the KLX250R exhaust makes no difference. Carby is a 32mm instead of 34mm, and the timing is different
KLX250R 5 BTDC, 40 adv
KLX250 5 BTDC, 35adv
KLX250S 10 BTDC, 34 or 39 adv.

 

Oh I am not doubting you Bernie! This subject has been up before but nobody has been able to crack it. What I am hoping is that someone will do the mod and take pictures along the way for the less tech savy of us! If people get their eyes up for this mod you will become of same legendary status as Marcelino

I checked the manual of my EFI out.

Carburation system: DFI (Digital Fuel Injection) system, keihin single barrel ø34
Starting System: Electric starter motor
Ignition System: CDI
Timing Advance: Electronically Advanced
Ignition Timing: BTDC 10º @1300rpm ~34º @11000rpm

Is any of this (disregarding carburation) different from the US/AUS spec KLX?

This post also has a lot of good information. Im copy/pasting
----------------------------------------------------------

The KLX250 D1,D2,D3,D4 bikes were the most powerful for the engine size (only 1 hp less powerful than the KLX300 A2.)

KLX250 D1-4. (non US model) 32 HP @ 8500rpm (US model) 30.5 HP @ 8500rpm.
Ignition timing: 5º BDTC @ 1700rpm to 40º BTDC @ 3000rpm

Dry Weight 104 KG.

KLX250 E1, E2, E3. bikes were heavier (rack large glass headlight etc.) and pretty much what we get today.

KLX250 E1-3. AUS spec 25 HP @ 8000rpm.
Ignition timing: 5º BTDC @ 1300rpm to 35º BTDC @ 5000 rpm.
(This is the ignition the I have on my 07 KLX250RH7 AUS spec bike, OE. Seems it can be traced back all the way to 94 with the E model bikes.)

KLX250S (09 and on.) AUS spec 23 HP @ 8500rpm (US spec) 15 HP @ 8000rpm.
Ignition timing: (US spec) 10º BTDC @ 1300rpm to 25º BTDC @5000 rpm. (AUS spec) BTDC 10º @ 1300rpm to 35º BTDC @ 5000rpm.

KLX300 A2. (AUS spec) 33 HP @ 8500rpm (US spec) 26 HP @ 7000rpm.
Ignition timing: 10º BTDC @ 1700rpm to 40º BTDC @ 3000rpm

 

Bernie, I think we're just struggling to catch up and understand what is obvious to you from your career with these bikes.
We've been looking for more power and we've had 2 options - the cam mod or the big bore. Now it seems like you've provided a 3rd that will work along with these mods, whereas before it was one mod or the other, mixing the two mods brought poor results.
I'm reading up on timing and the like, then I'll have some 3 year old questions for you.
Like how to change the BTDC timing from 10 to 5.

And what's your position on the JB Weld idea to stick the metal? Seems like a lot of RPM to inflict on that stuff, as tough as it is. Failure would be bad...

 

I still don't understand how mechanically altering the static timing is going to net power when it was proven with the timing adjustable CDI that it did nothing.

Lets say that the CDI has a maximum advance range of 25 degrees and you set the timing mechanically @ 5 degrees at full advance you'll have 30 degrees. Now you set the timing at 10 degrees and at full advance you'll have 35 degrees.

how is that not the same as the adjustable CDI ?

 

just turn the friggin rotor.. 3mm should be 5 degree, no need to weld to check.. my the first try when I tested , was.. I glued it..and it worked.. as I said..i did that over 20 years ago..some stuff just works... and there wont be any damage when the ignition is not spot on..
why does a smaller carby produce more power on the KLX250R ???

due to noise and emission changes in modern countries.. every model is slightly changed over the years.. and since all "hardware" hasn't changed over the years.. it must be the "software"