report: CDI modification
#12
04-05-2007, 07:10 AM
RE: report: CDI modification
ORIGINAL: Nobrakes
Excellent write-up, Bryan!
Excellent write-up, Bryan!
#13
04-05-2007, 07:44 AM
RE: report: CDI modification
Most people opt for the 250SR box instead of the KLX300R boxbecause the 300 ignitor advances too far, too quickly for our displacement
#14
04-05-2007, 02:07 PM
RE: report: CDI modification
I would be inclined to agree with that. I think the added displacement on the 331 will more than offset any low-end torque issues.
ORIGINAL: mooredan
Might this mean that the KLX300R CDI might be a better "fit" for a KLX250S big bore (331cc)?
Most people opt for the 250SR box instead of the KLX300R boxbecause the 300 ignitor advances too far, too quickly for our displacement
#15
09-28-2008, 03:13 PM
Also, the KLX250SR CDI is no longer available off the shelf. It has been replaced by the KLX250ES CDI, PN 21119-1533, which has a less agressive advance, but is much better than the one on the KLX250S. I'm running with the -1533 right now, but if I could find an SR CDI, I would go with that in a heart beat.
You can only find the SR CDI at auctions now and they sell quickly because they are becoming very rare. You're lucky to have found that one, Nav.
#16
03-17-2009, 11:01 AM
Tremor,
Where does the -1399 curve take place? It is listed as being from a 250SR, not sure the year. Was able to pick it up along with the factory harness. Going to compare to mine and see if it would be easier to just swap the harness rather than splice the wires. Wondering about the timing curve though, and I know your local bike shop has the info.
Where does the -1399 curve take place? It is listed as being from a 250SR, not sure the year. Was able to pick it up along with the factory harness. Going to compare to mine and see if it would be easier to just swap the harness rather than splice the wires. Wondering about the timing curve though, and I know your local bike shop has the info.
#17
03-17-2009, 01:08 PM
Tremor,
Where does the -1399 curve take place? It is listed as being from a 250SR, not sure the year. Was able to pick it up along with the factory harness. Going to compare to mine and see if it would be easier to just swap the harness rather than splice the wires. Wondering about the timing curve though, and I know your local bike shop has the info.
Where does the -1399 curve take place? It is listed as being from a 250SR, not sure the year. Was able to pick it up along with the factory harness. Going to compare to mine and see if it would be easier to just swap the harness rather than splice the wires. Wondering about the timing curve though, and I know your local bike shop has the info.
**The curve is 'somewhat' similar to the KLX300R... 5degBTDC@1700RPM and 40degBTDC@5000. The KLX300R CDI curve is a little steeper. It advances to 40degBTDC by about 3500RPM.** The 250SR CDI is slower to advance in order to facilitate better low end torque with the smaller displacement...MABT (Minimum Advance for best torque)..**
As for the exact shape of the curve I couldn't tell you. Once you get it installed, fire it up, get an advance timing light and some graph paper, then plot us a curve...you could be a pioneer
Last edited by tremor38; 03-18-2009 at 01:38 AM.
#18
03-17-2009, 07:37 PM
Most people opt for the 250SR box instead of the KLX300R boxbecause the 300 ignitor advances too far, too quickly for our displacement. It has to do with keeping the low end torque optimal. The more retarded timing curve on the 250S has more to do with emissions than anything else. The cam profiles on the 250SR and 250S are identical, so that's not an issue.
