CR250 Ignition, studied all day. This is what I think.

[maddog1927]

So I have been studding all the cr250 ignition posts these are my findings:

The Analogue (’96 and before)

Attributes

Direct fit no mods required (93-96) (may require bracket mods for CDI / Coil)
Increased handling performance…. Does not want to “stand up” in corners
Added mid range and top end.
I have not found a timing curve map, but would guess that the curve is similar to the other OEM curves.
Starting not improved.


The Digital (’97 and after)

Attributes
Up to ’01 easy to mod using a router and o-ring. (not sure about ’02 to ’07)
Increased handling performance…. Does not want to “stand up” in corners.
Added mid range and top end.
The “digital” can be reprogrammed with custom timing curves.
Easier starts this may be explained by the timing curve maps, the digitals come to life at a lower RPM.
Holes may need to slotted to allow for timing to be advanced 10 degrees or so to get optimum performance.

It would appear to me that the majority of the increased performance, both in handling and in the top end can be traced back to the lighter flywheel. Unless you plan on custom curves the digital will only give easier starts over the analogue.

The timing curve page shows all the oem curves in the same ball park. They all ram up to some healthy timing advance, and then as the RPM increases the advance decreases. The 250 does not decrease its advance quite as quickly as the 500, but definitely within the same ball park. It is not till you get to the aftermarket CDI that you see some major timing curve changes.

I would like to try a lightened 500 flywheel and see if the results are similar to that of the 250 ignition.

Also does anyone know if the ’02 to ’07 ignition is compatible with the 500? Does the flywheel fit?

Is the stator plate even close to fitting? I ask because I want to do a 3rd gen AF. If I could get the light flywheel, the easy starts of the digital, and the coolness of perfect fit of the coil /CDI in the oem mounts…. Too cool.

[nmdesertrider]

93-ish 250 ignition

Easy start, three kicks when it has been sitting, one kick after it's been run

transition to on the pipe a little less abrupt

much much better quality unit. We've had all kinds of problems with stators burning out on the 500 - 250 unit you can set it up and forget about it

[seanmx57]

Lightened flywheel does NOT equal a smaller diameter flywheel of the same weight, not even close.

[dannygraves]

um, I don't know wh9o has experienced less "stand up in the corners" my 250 ignition stood up WAAYY more, the first time I took it out I looped the thing. I keep telling people not to get a 250 ignition to mellow out the bike.

The '02+ does fit, same stator plate as '97-'01 and the flywheel does bolt on and its a tiny flywheel. you need to adjust timing on the '02+ though, it doesn't just bolt on and go.

[hoofarted]

The Analogue (’96 and before)

Attributes

Direct fit no mods required (93-96) (may require bracket mods for CDI / Coil)

CDI fits fine in rubber boot. Coil is smaller. Works better for AF conversions

Increased handling performance…. Does not want to “stand up” in corners.

Does not? Nah, mine stands and slides just fine!

Added mid range and top end.

Oh yeah! Best part of this ignition. Works super with FMF Fatty IMO

I have not found a timing curve map, but would guess that the curve is similar to the other OEM curves.

Similar to OEM? Not sure.

Starting not improved.

Bullshit. Mine starts 1st kick, every time; hot or cold. And the flywheel is lighter - revs much better.

Trade offs running 250 ign + FMF Fatty = slightly less bottom end, but rips on mid/top!

[maddog1927]

Lightened flywheel does NOT equal a smaller diameter flywheel of the same weight, not even close.

Kinda like standing in the center of the merrygoround huh?

Hoofarted... thanks for your input. You running the anologe set up? have you tried digital ... your opinion on the 2?

[hoofarted]

Ya I am running the analog setup...93 to be exact. I went this route due to cost/availability. I waited too long before deciding to jump on the bandwagon - everyone snatched up the 00/01 ignitions and I found a 93 setup for cheaper. I didn't feel like paying upwards of $200+ on fleabay - so I cannot comment on the differences.

[craigf40]

So I have been studding all the cr250 ignition posts these are my findings:

The Analogue (’96 and before)

Attributes

Direct fit no mods required (93-96) (may require bracket mods for CDI / Coil)
Increased handling performance…. Does not want to “stand up” in corners
Added mid range and top end.
I have not found a timing curve map, but would guess that the curve is similar to the other OEM curves.
Starting not improved.


The Digital (’97 and after)

Attributes
Up to ’01 easy to mod using a router and o-ring. (not sure about ’02 to ’07)
Increased handling performance…. Does not want to “stand up” in corners.
Added mid range and top end.
The “digital” can be reprogrammed with custom timing curves.
Easier starts this may be explained by the timing curve maps, the digitals come to life at a lower RPM.
Holes may need to slotted to allow for timing to be advanced 10 degrees or so to get optimum performance.

It would appear to me that the majority of the increased performance, both in handling and in the top end can be traced back to the lighter flywheel. Unless you plan on custom curves the digital will only give easier starts over the analogue.

The timing curve page shows all the oem curves in the same ball park. They all ram up to some healthy timing advance, and then as the RPM increases the advance decreases. The 250 does not decrease its advance quite as quickly as the 500, but definitely within the same ball park. It is not till you get to the aftermarket CDI that you see some major timing curve changes.

I would like to try a lightened 500 flywheel and see if the results are similar to that of the 250 ignition.

Also does anyone know if the ’02 to ’07 ignition is compatible with the 500? Does the flywheel fit?

Is the stator plate even close to fitting? I ask because I want to do a 3rd gen AF. If I could get the light flywheel, the easy starts of the digital, and the coolness of perfect fit of the coil /CDI in the oem mounts…. Too cool.

hi the 02 - 07 ignition works well with the smaller flywheel and complete ignition system you just need to slot the adjusting slots out a bit more ...about 12mm and advance the stator plate.i think it makes the 500 a completely different bike a lot more rider friendly iv read that that system 02-07 ignition has a traction control system and i swear it works you wont notice immediately but after a few rides you will even a worn back tyre and you still seem to just pull raw power out the bike no power wasted or very little wasted well thats what i experienced on my bike and im very happy with it and the starting is a lot better

[MICK]

um, I don't know wh9o has experienced less "stand up in the corners" my 250 ignition stood up WAAYY more...

Given your definition I don't think many could disagree. Although my use of this phrase describes a much different phenomena.

Over the last ten years of racing 500cc two strokes, I'm repeatedly frustrated by the overshadowing effects of gyroscopics. Every turn, every corner I deal with this bitch, pumping up my arms and fatiguing me by motos end. For the record let me say as a racer, no other aspect of competition do I exert more energy then trying to SLOW THE HELL DOWN!!

Through practice you find you need X amount of crank speed to tip the bike into the turn, followed by X amount of crank speed to keep your line, or god forbid change it mid corner. So I have to begin setting up for corners sooner than my competition, which is no bueno when many of them are on 450s. Failure to do so leads to "push" into the corner, I miss my line and fall of my pace / rhythm. Once negotiating the corner, only carefull application of the throttle keeps me pointed in the direction I want to go. Too much and the bike begins to "stand", raising my center of gravity and prohibiting me from maintaining my current line.

All of this I can best explain as "weight". Some magical force that adds pounds to my machine in correlation to crank speed. A 500cc two stroke just feels a good deal heavier not only in turns, but also scrubbing speed than it actually does.

The culprit is almost entirely the crank itself. Which we can just about do nothing about. However I've noticed the smaller 250 flywheel does reduce this gyroscopic phenomena to a noticeable degree. Improved turn in response, reduced tendency to stand up and quicker crank deceleration times all contribute to help me come into corners hotter, catch inside lines easier and more consistently, and get back into the power sooner. I feel the 250 flywheel does this so well, the benefits can actually be measured and recorded.

So how much does the 250 rotor help? I feel it quite literally takes 15-20 pounds off the bike.

[dannygraves]

ok, that makes sense, I assumed we were talking about power delivery and not gyros and weight.

[MICK]

Well the others might have been?

Beings how I can be quoted many times as to speaking on the 250 ignitions characteristics, I thought for future reference I'd define what "Stand Up" is to me and the phenomena I'm referring to when I use this term.

In your case Danny I also agree. However I associate that trend of the bike's behavior with gravity...and our machines damn little respect of it

[dubious01]

agreed, gyroscopic forces make the bike stand up as it revs, and so I cannot wait to see how a 250 rotor will be on my bike.
Are you guys really impressed with the new ign curve from cdi as well?

[dannygraves]

the ign curve is the primary reason for the mod.

[MICK]

And that's where I disagree.

At race's end, I'm far more pleased with the handling ability of my bike. Usually saying between breaths, "damn this thing handles like a son-of-a-bitch for a 500cc two smoke". I absolutely, positively could not ride as hard, for as long, and finish as good if the bike didn't handle like this. The power characteristics are second fiddle to me, and I feel most of those traits are due to the flywheel as well (faster accelerating and decel crank speeds).

This of course was all a surprise to me. Did I expect a change in handling due to the smaller rotor? Yes of course. But I thought it would be similar to removing a FWW. What I expected was gratuitous amounts of raw earth moving horsepower. What I actually got couldn't have been more 180° than expected.

But this of course is all for my bikes specific application. How many guys race MX on 500cc two strokes anymore? Quite honestly many of you probably wouldn't like my bike's setup at all. It behaves much differently than any other bike I've had before. But in a Weekend Warriors world of 250 two strokes and 450 fours, I need to make my bike as un-500-like as possible to claim that I'm even a "competitor". I've ridden A LOT of 500s with substantially more power, but I've never ridden a 500 as fast around a track as mine. If that makes any sense, you understand why the 250 ignition has become a handling improver to me above power.

[dannygraves]

makes total sense, the same way that honda detuned the 500 because taming it down got better lap times

[FZ1426]

And that's where I disagree.

At race's end, I'm far more pleased with the handling ability of my bike. Usually saying between breaths, "damn this thing handles like a son-of-a-bitch for a 500cc two smoke". I absolutely, positively could not ride as hard, for as long, and finish as good if the bike didn't handle like this. The power characteristics are second fiddle to me, and I feel most of those traits are due to the flywheel as well (faster accelerating and decel crank speeds).

This of course was all a surprise to me. Did I expect a change in handling due to the smaller rotor? Yes of course. But I thought it would be similar to removing a FWW. What I expected was gratuitous amounts of raw earth moving horsepower. What I actually got couldn't have been more 180° than expected.

But this of course is all for my bikes specific application. How many guys race MX on 500cc two strokes anymore? Quite honestly many of you probably wouldn't like my bike's setup at all. It behaves much differently than any other bike I've had before. But in a Weekend Warriors world of 250 two strokes and 450 fours, I need to make my bike as un-500-like as possible to claim that I'm even a "competitor". I've ridden A LOT of 500s with substantially more power, but I've never ridden a 500 as fast around a track as mine. If that makes any sense, you understand why the 250 ignition has become a handling improver to me above power.

I dig what yur sayin. I wouldn't call myself a guru, and I don't necessariy "race" my 500. But I can compare it "real time" back to back with 250's and 450's.

There's a reason they don't build 500cc MX two strokes anymore, for the same reason(s) they don't run 500cc two stroke moto GP anymore.

(As you know) 500's are just nasty and hard to ride. The power characteristics are just not conducive to being able to put it to the ground in anything resembling a controlled manner. Racing one against either a 250 two stroke or a 450 four stroke is masochistic.

Challenging, very fun, and slightly masochistic. Perhaps a bit like swatting at flies with a sledgehammer...

The 250 ignition sounds cool, but it's never gonna make my 500 as easy to ride as my other bikes.

[asteroid500]

im with you Mick...any one can go fast in a strait line, try stringing back to back laps with consistent times....it aint easy but when your in the groove boy does a purrrinng 500 sound good, almost effertless to watch, although riding it aint.

Soft bikes make shit riders look good, & hard bikes make hard riders look CRAZY!...bbbrrraaaapppppp duuunnnggg duunnnnnggg......bbbrrraaaapppppp

[dubious01]

I don't care if I'm slower on a CR500 or not. Honestly its about shits and giggles, and grins per $.

Same reason I have a turbozx14.... I an't a world champion, .... but I feel like one when i ride the fucker! LOL
Since the tights don't fit anymore I just wear my superrman boots and my cape when I hit it! hahaha

[stu460]

I an't a world champion, .... but I feel like one when i ride the fucker! LOL


Well said,made me laugh

[asteroid500]

Stu...you caught my attention....The Toe Cutter...
I always liked "see you on the HWY scagg"
Gotta love a V8 coupe

[mxdogger]

Mick thanks for putting into words what im feeling. Im looking to make my 500 afc mx worthy. the 93 cr250 analog ignition i installed is more to my liking than the 2000 digital (please hoons im not selling it yet) or the 500 system. I raced my 500 for the first time this past weekend and only the second time i have ridden it on a track. My results where as expected, 8th and a 6th for 7th overall, i did get to pass some 450's. had i not been knocked down on the start by a dirty rider ( i was 3rd to the 2nd turn) i would have placed better. I rode my crf 277 and the cr500afc in motos that day, the 500 handled just as well as the 4t ! riding the 4t actualy helped me crossover to the 5'0 by gaining confidence in the track.

To get back to the thread, i feel it is nessasary to detune the 500 to a more managible state for mx racing if i want to be competetive and show up the competition. My next step is to try a 36mm carb, that should take a few ponies away to slow it down some. 2nd is to install a bigger tire a 120/80 19 geomax 51, 3rd workout,workout workout,

[kdizzle]

I race my 500AF in WORCS, Local AZ desert GP's and local mx series. Yes it is a hard bike to setup and race, but it will make you a better rider if you can overcome. the bike has HUGE poential, and i know there is still lots of performance in the bike, if i can learn to unlock it.

My tips

- you must be in great physical shape to ride one hard.
- you must learn to work the suspension clickers, getting the chassis to be stable and the rear tire hooking up. suspension is not a setting, but an adjustment
- the motor needs more overrev period. Do not do anything to shorten the overev, rather try to increase it.
- controls must be perfect. throttle snapping back firmly, clutch buttery, front brake providing good feel and low effort. Armpump is an iussue with the big power, so try to help yourself out. Working to nullify the vibes are a biigie too, so they dont wear you out.
- good riding technique, this is one im working on, practice riding very tidy and let the power do its job. I know I can pass on the straight if I need, so I concentrate on getting the corners right and closing up on the bike ahead of me, so i can cream him with roost out of the corner.
- when you do make a pass, roost the shit out of 'em. Once the 5 chucks a few rocks at em, they will fall back.

I cant ever recall feeling that I was hampered by the power of the 5hundy. rather I feel I need more suspension and better setup. the bike has loads of potential, and can do the business if you are a good enough rider.

I have never owned a bike that has intriged me so much, I could go down and get a 450 whenever I feel I need to, and next year if this bike is wore out i just might. but man there is something about it that makes me want to spend all my $$ modifying and tweaking to get the most out of her.

or maybe the two stroke smoke is clouding my vision

[asteroid500]

"roost the shit out of 'em. Once the 5 chucks a few rocks at em, they will fall back."
Yeh bowl Asteroids at'm that sorts the bastards out........I'm lov'n your piece KDZLE

[nmdesertrider]

When I have a loud 450 behind me it gets quiet really quick when I hit the straight. This always warms my cockles!