125-200cc Uptite 167

dfeckle,

The map in my 09 CDI should be nearly identical to yours and yes it doesn't compare in the mid-range to the 04. The JD ignition is loaded with the stock 04 map and another map that I am not sure of when you buy it. I have ordered the usb connector and software to be able to program it with the lap top. So I am still waiting to be able to use this cdi. The JD unit that FBF sells has connectors that work with the old wiring harness. I haven't put together a set of connectors to hook it up yet. That's next on my to do list.

Thanks, Wally. I'll stay tuned.

Did you really get the JD ignition setup for $99? They have it listed for $399 on their website.

Yes, go to the FBF e-bay store and they list them. The dual switch setup for your bars is also there an I think it was $13. They have them for both the CR 250 and CR 125.

In my WR250 service manual there is a graph of the CR and WR ignition curves. Perhaps the various years of 125 service manuals have the same information?

Does anyone know what it cost to convert a WR to CR ignition using all new parts?

NWRider,

Bryon at Bill's gave me a quote of 195 for the stator and flywheel assy. The CDI assembly is 142. I will let you know how easy it is to program the JD once I get the software.

Walt - If you didnt ride the cr167 of Kevin s on any trails or hills could it be that the extra mid power is actually the lack of flywheel/alternator? weight that you were not used to and you wouldnt feel the lower torque ( compared to wr ) unless you rode some tricky hills

or have you ditched the wr alternator on yours ?

I've got both, a '00 CR125 w/167 kit and an '07 WR125 with 144 kit. For racing, the 144 is the ticket, faster and smoother. For trail riding or lesser skilled rider, the 167 would be the way to go, lots more torque, but vibrates quite a bit on top and parts supply is ??? without buying full piston kit, at least he had no parts when I asked. 144 kit uses same wiseco piston as jap big bores, so rings, clips easily accessible.

Rockdancer,

I was riding them back to back over some varied terain. The 09 WR 167 doesn't have the mid-range bulge the 04 CR 167 does. Wasn't a flywheel effect. I have installed off and on many FWW and know the feeling.

Dirtaddict,

My hands must be made of stone because I don't notice the extra vibrations. Of course when I think of a vibrating issue it is my WR360. I don't know about the 144 being faster, it just revs higher easier. If you are a lard butt like me that tends to not be much of an advantage.

Your '09 WR167 doesn't have an '09 cylinder though, correct?

Norman,

That is correct. I believe it was off an 02 or 06 but the cylinder was the same for both. The rear transfer on the newer cylinders will limit bore size even in the new 144 oem cylinder.

Now your in my wheelhouse

I ordered one of the JD dual map ignitions and switches from FBF--the price was too good to pass up for the possibility of a meatier midrange. This should be a fun little winter project. Hopefully the different connectors between the newer ignitions and the older ignitions don't make the conversion too difficult. Also, I hope that the older ignition timing curve works well with the newer cylinder.

Looking at those graphs, they seem strange. 28 degrees BTDC at 2,000 RPM goes against everything I know. Also, why beging retardining the iginition rapidly above 9,000 RPM? Seems to me you'd need the most advance at those speeds so there is enough time to let the fuel burn fully.

Looks like I'll have to break open the homework books.

In any case, it looks like you could get some real benfit out of advancing the ignition on a WR by about 5 - 6 degrees.

I thought the reason the advance is backed off at high rpm is to avoid melting a hole in the piston. Don't all bikes do this or am I mistaken?

The CR shows a lot more advance but I am not sure it that is the totoal or just what the ignition adds. Maybe the stock position for the WR timing is more advanced than the CR? Maybe Wally knows. There are instrutions for how the set the CR and WR timing in the manual so I guess I could look and figure out if they are different.

I do not know much about ignition parts so if one were to buy the stock flywheel do you still need the stock CDI or is the JD unit a substitute?

NWRider,

The JD CDI replaces the stock CDI so you don't need to buy it. The CR's do use a different coil.

BillO,

I was scratching my head over the same thing. I am an antique when it comes to ignitions as I haven't done any real work messing with one since the motoplat days. Stick the position pin in and then advance 2 degrees. We definitely aren't comparing apples to apples between the two wr and cr ignitions. It's been 34 years but I think that my last husky 125 in 76/77 had initial advance at ~18 degrees and I advanced to 20 to 21 for best top end. Damn that's a long time spent in a black hole. The industry has come a long way since I used a degree wheel and dial indicator.

If you advance the WR more than about 2-3 degrees starting becomes an issue when I tried it.

Bill, the timing is retarded at higher rpm due to turbulence in the
combustion chamber, making the mixture more volatile, the goal is to keep your peak combustion pressure at approx. 10* after tdc.

Just to throw in my own confusion - Im pretty sure I read the other day on Eric Gorrs tips- that advancing the ignition gives better snap in the mid range but takes away from the top end over rev
This seems right to me in that the WR has less snap but more over rev than the CR or a YZ

Info from this site - good article on rebuilds etc
http://www.off-road.gr/article25.html

Ignition Timing

The ignition timing has a minimal affect on the poweband. Retarding the timing has the affect of reducing the hit of the powerband in the midrange and extending the top end over rev. "Overrev" is a slang term that describes the useable length of the powerband at high rpm.

The scientific reason for the shift of the powerband to extremely high rpm, is because the temperature in the pipe increases with the retarded timing, and that enables the pipeʼs tuned length to be more synchronous with the piston speed and port timing of the cylinder.

Advancing the timing has the affect of increasing the midrange hit of the powerband, but makes the power flatten out at high rpm. The reason is that the relatively long spark lead time enables for a greater pressure rise in the cylinder before the piston reaches TDC. This produces more torque in the midrange but the high pressure contributes to pumping losses at extremly high rpm.