125-200cc WR125 to CR ignition mod - notes

[BillO]

For all of you considering this mod, or have already done it, here are some notes from my effort for consideration/comment.

1) This is the correct flywheel puller for the WR. As much as I tried, I could not find the genuine Husky part, but found this one for $10 at: http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=370509877357&ssPageName=STRK:MEWNX:IT



It got the flywheel off in about 5 seconds.

2) I have also had no luck tracking down the timing tool, however after some careful measurements and observations on our previous CR and another, the following gives the correct timing. Use a dial gauge to ensure the piston is precisely at TDC. Then, as shown below, the dot on the flywheel, and the end of the trigger magnet should line up with the gap in the trigger pickup head. It would be great if someone else with a good running CR, or who did the timing using the Husky tool, could corroborate this.




3) The manual indicates the correct torque for the flywheel nut is ~78Nm. This seems excessive. It this what everyone else has used?

I'll update this post after we test properly.

 

[TROFFER88]

I would be interested in what you think performance wise. I did the conversion and I dont think the difference is that dramatic

 

[R_Little]

I would be interested in what you think performance wise. I did the conversion and I dont think the difference is that dramatic

Most people used to go the other way...CR to WR for woods.

 

[NWRider]

Most people used to go the other way...CR to WR for woods.

I guess not anymore. I put a complete WR ignition in the classifieds a while back and did not get a single response.

Personally, I like the CR parts a lot better in the woods.

 

[BillO]

Well, in 2 hours of testing today, the results were very good. This cost about $250 and produced the best performance increase, for the money spent, over anything else we have done (144 kit, pipe and silencer). My son has two races on the weekend. I'll report back after.

I would be interested in what you think performance wise. I did the conversion and I dont think the difference is that dramatic

How did you do the timing?

 

[TROFFER88]

Walt let me use his timing tool. The CR ignition was used and the stator had washer marks on it . I verified them with the tool , they were correct , I then added 1 degree of advance to it. Iam not saying it wasnt a nice improvement , just not Holysh!* this runs good now. I also think the bottom end / rev on my motor was weak due to low compression (oem 144 - 135psi) , I think it needed a new ring and thinner base gasket. I dont know what a oem 144 should have for compression but I would like to see 180 psi with the squish set right. I took it off and installed my 167 top end so we will see then.

 

[NWRider]

Get a new ring on there and maybe it will be better. They are cheap and last time I checked Motosportzs had a bunch of them. 180psi is about right with the squish set. Mine was a bit loose stock (1.2mm).

 

[pvduke]

Well, in 2 hours of testing today, the results were very good. This cost about $250 and produced the best performance increase, for the money spent, over anything else we have done (144 kit, pipe and silencer). My son has two races on the weekend. I'll report back after.



How did you do the timing?

im listening...*wringing hands*

 

[TROFFER88]

I pulled the 144 and went 167 , I didnt want to re-ring while I was waiting for the 167. I am thinking of selling the 144 if anyone is interested.

 

[Last Lap]

Is there one part number for getting everything that is needed to do this?

 

[R_Little]

I guess not anymore. I put a complete WR ignition in the classifieds a while back and did not get a single response.

Personally, I like the CR parts a lot better in the woods.

My CR135 has a violent hit and wicked top end......and my Wr144 has all bottom and mid...no hit.

I don't know if it is the cylinder or the ignition.

 

[NWRider]

Probably the cylinder unless the jetting is way off. My CR144 does not really have much of a hit and that is with the timing advanced. If it is retarded about 2 degrees it is almost electric.

 

[BillO]

Is there one part number for getting everything that is needed to do this?

Not that I know of. I was quoted nearly $600 (with applicable taxes) for all the OEM parts new from Husky. eBay searches and other sources netted me 2 and a half kits for about $475.

 

[BillO]

Here is a little update.

After 2 races on this ignition, we are certain that the performance increase is the best bang for the money you can do to a WR 125. And that would be true too if we paid full retail for brand new parts. Pat (my son) was able to come 2nd in both hole-shots and ran 5th for 80% of the first race, finishing 6th and ran 4th in the 2nd race against a class full of 450's and 250 2 strokes.

You get a decent power increase from just over idle to the over-rev with a huge punch in the middle. So much so that he can ride a gear high in the woods and almost treat it like a 250 (read lazy shift foot). He says it takes far less energy to ride in the woods than before and is able to fend of 450's on the straights. Not half bad for a 144.

So, we went ahead an did a similar mod to our 2009. This one is using a KTM 125 EXC stator coil, KTM 125 SX module, and a Husky CR 125 base plate, flywheel and trigger coil. This kit cost me only $200 because there is no 'hot rush' on KTM parts. Just finished this mod and I took it for a test ride in our little back yard track. OMFG! Not sure if this is because of the KTM ignition components, or that this is just a better engine, but it is significantly faster than the bike mentioned above. I was amazed at the previous one when I tested it because it would wheelie in 2nd and 3rd with my fat 250lb carcass on it just by opening the throttle, but this one is insane. Not only does it wheelie, it spins the back tire! I honestly feel this bike is as fast as my WR250, or maybe even faster because it handles so much nicer.

My son will be racing this one out west in 4 races over the next 3 weeks. I'll update after that.

 

[pvduke]

man that's cool. really tempting too.

 

[LawnDartMike]

Any specifics on the KTM parts like year, model, etc?

 

[BillO]

The stator coil was a after market item I found on eBay that was supposed to fit 1998-2005 EXCs. The CDI module was from an '06 SX, but I think the part number is and has been the same for some time, and is also the same as for the 150 and 200.

 

[BillO]

I can't say that for sure as I have had no time to test other CDI modules on that bike. To tell you the truth, I suspect not, as other than a mounting tab (which I cut off) and a paper part number sticker, the KTM module is identical, including other markings. I will do some testing once we get a break in the race schedule, but it won't be for another 4 weeks or so. It is certainly worth testing though.

There would be no other changes required if you are starting with a CR.

 

[chappo]

Hi All,

I've picked up a CR250 ignition of eBay and want to install it this weekend, but can anyone tell me if the flywheel nut on the WR is a left hand thread?

What has everyone used to hold the flywheel while undoing the nut?

Thanks!!

 

[BillO]

Are you thinking of putting this on a WR125? I'm not sure a CR250 ignition would fit a WR125.

I'll assume you are putting it on a WR250. The nuts all have a standard right hand thread, as far as I remember. It's been a while since I had my WR250 flywheel off, so someone can feel free to correct me if I'm wrong. The puller for the WR250 has a left hand thread though.

To get the nut of, I usually just hold the flywheel with my hand and use an air-impact driver. To tighten it I use a torque wrench and hold the flywheel with one of these combo clutch/flywheel holders;