A while back I read on the forum about a company trying to build a CDI that would give the US bikes around 35 degrees final advance instead of 25. I also read on a link to another forum of a guy working to build one, but I never heard if he ever got it right. Also on the link there was someone who said they were running a CDI off of a KLX250EX and getting the 35 degrees final. I don't know a whole lot about motorcycle advance, but I grew up racing small block Chevys and 25 to 35 is a huge difference in your final. Does anyone know of any CDI's that will cross over if any are not available for these bikes? It would be awesome to have a bike that you could get at about 15 degrees initial and have 32 - 36 final!

 

Would one off a Mojave 250 qwad work?

 

AUS and NZ spec bikes have em.

 

Funny reply WestOzKLX, but I think I read somewhere that yours wont crossover so if no one is making them we in the U.S.A have to find something that will adapt in. No matter how much we do to our bike for performance they will always be running retarded on the final and that kills power. The explosion in the combustion chamber is happening after the piston has rocked over and started back down

 

Like trying to ride your little brothers trike down that big hill. Once you get going, no matter how fast you pedal, you can't keep up.

 

It's not just the final advance, but how fast it comes in. Some of the markets have a fixed advance curve and others that use tps can be variable depending rpm and throttle position. The specs you look up in the book may just reflect what the numbers should be in a test situation. on a stand with a timing light?

It does reason though you wouldn't want a lot of advance in the leaned out models for fear of detonation, so I'd suspect the older pure offroad and markets that weren't corked up (and come with big main jets) did use a more advance. just thinking aloud though.

 

Heres a question. How would you go about to check the IGN timing on the KLX? It doesn't have a marked crank pulley like vehicles do.

 

I don't have the spec's or wiring diagram for the "S" model, but the KLX250 "D" series and the KLX300's spec is 5 degrees BTDC at 1,700 rpm and 40 degrees BTDC at 3,000 rpm. The KLX250 "E" series spec is 5 degrees BTDC at 1,300 rpm and 35 degrees BTDC at 5,000 rpm.

Ride on
Brewster

 

You can use a timing light with advance or 'set back" dial on it. Just dial the timing light in so the tdc mark lines up at different rpms and note where the dial is each time.

A possible way to bring the timing in faster on the tps bikes would be to fool the tps into thinking the throttle is at a small or smaller opening. (Big throttle openings at lower rpms will select less advance on the map) your still limited to max on the map though.

Another option is an offset key for the flywheel, or moving the stator plate. personally I'm not sure you'd gain much, I've seen 4 degree advance rotors gain a little bit somewhere but lose it somewhere else, usually on the top end. 40 deg seems like a lot on our crap gas, but hey it might work good too?

where I think more advance would work well is with the big bore kits

 

Is it possible to move the stator plate? Does anyone have a good picture of one on the bike they could post an 09 would be good for me. Offset keys are scary they have a tendency to shear at the offset. I don't think big bore would make a difference unless you change rod length, because that will change piston dwell at TDC. 40 degrees is to much in my opinion. Depending on our piston make and quench area in our head, if they have a quench area, plays big in your timing.But moving the stator would be good, it would move the whole curve.