125-200cc First ride 09 WR 125 and the bog

Thanks! And it is great having a source for all the parts!

JS

Well....the carb craziness continues. I took the bike out today as the last day of the TMX. I rode the bike for about 15 minutes and noticed the exhaust did not have the usual flood of goo coming out of it. The bike was also just flat....no power anywhere.

So, I thought to myself...hmm. Why not? I pulled the carb and throw in a 45pj, 470m, moved the needle from the 5th to the 4th clip and fired it up. 4.0 slide Walt's orange and blue springs, PV adjusted to the top

To my surprise, the bike ran really, really well. Bog no longer a bog just a bit of a flat spot. The bottom ripped and the top ripped. The top still feels a bit lean so I am going to bump up to a 480 tomorrow and throw the stop PV spring back in for a baseline run.

I just do not get how I can go from 32.5pj, 450 main, 4th/5th clip at 40-60 degrees and have spooge flooding out. Then bump everything way up and have just a dribble?????

Hotter temperatures does make the bike richer, right?

In any case, the PWK is going on, but first I need new tires and have to fix a leaky fork seal (new thread on that one).

JS

I got mine working damn good today! Adjusting the power valve linkage up, and a few jetting quirks and this thing is awesome!

The trails today were mostly 1st and 2nd gear.....but holy crap this thing lugs. The bottom end is so crispy and meaty. I love it, 2nd gear and its got torque from idle, I could ride most of the nasty twisty rooty crap just before the PV opens. It literally feels like a 4 stroke....until the hit. But thats just more fun. I have walts Yellow and Green springs in I think.

Its a little flat on top, but I can work with that another day. The bike has really grown on me in 2 rides. I was railing tight switch backs today that I would be bobbling on my TC250.


I think im a little excited!

Heres my jetting setup...

PJ 50
Main 470 (I think)
needle 3rd clip
AS 2 turns out

When you adjust your PV linkage up you are pre-loading the governor springs. This accomplishes two things it keeps the pv's completely shut until they actually reach an rpm necessary to start the opening process and it does lower the rpm that they do open at. I had to change from my orange/green combination to the yellow/green combination to keep my opening rpm the same when I adjusted the linkage up the rest of the way. It eliminated the slight flat spot I did have after installing the PWK although the flat spot was almost eliminated by the PWK. My 144 is a complete torque monster this way. Rips the front wheel off the ground in the first three gears with just the flick of the throttle from well below the pv hit. I then started backing off the linkage to find when the flat spot would start to reappear. I ended up with the linkage about 3/4 of the way to the top and it has no bog what so ever and huge mid-range where it used to have a flat area. I did notice a slight increase in top end by backing the linkage down that 1/4, although I don't know when I would actually use it. I was previously running the linkage at about the half way point to insure the pv's ability to open fully but this does cause a flat spot and I think the pv's not only slightly open early but do not close completely unless the rpms are lowered drastically.

If you look at your linkage you notice the spring loaded attachement at the top that allows the linkage to move both ways in excess of the limited power valve movement. I think one thing that attachment does is allow the power valves to be forced slightly open from exhaust pressure at rpms below the opening rpms. This spring is fairly weak in its initial movement either way and unless the governor is pre-loaded enough to put a closing pressure on this spring it allows the pv's to do things that they aren't supposed to and loose the piston to pv tolerance needed to work. This is just a theory to try and explain why pre-loading the governor spring helps the below pv opening bog. One thing I do know is that these actions are hard to duplicate when there is no load on the engine. I think this is due to the small amount of actual throttle that is needed to spin the motor to earth shattering rpms under no load and the very limited exhaust flows while doing it.

All this is conjecture but I am just trying to understand what is going on. Because with the linkage adjusted all the way up the PV's remain partially closed and blocking high rpm flow in the exhaust throat. They aren't blocking the port itself, but they are protruding into the exhaust passage. JMHO

The bottom line is that now my 144 is much closer to the WR 250 motor I love than the frustratingly bad motor that I uncrated last summer. I was able to torque up a steep climb today in second gear that was a real struggle in 1st gear before I changed to the pwk and adjusted the linkage more.

Walt

Sounds good! I think!

All I know is that I was like this guy after riding today.

There is a huge difference in the torque of the little motor with the linkage screw adjusted to the top compared to having the screw on the bottom. It is hard for me to tell the loss of top-end, and I ride on some pretty fast open trails in Hollister. I wish we had a dyno of the bike with all the different settings.

With the jetting on the rich side the bike seems to have even more "meat" and 4-stroke-ish attitude down low. It is easily possible to run 1-2 gear single track a gear high without using any clutch.

With the jetting right, and PV adjusted I do not think there is a bike that can even come close to the WR125 in single track riding: technical or faster flowing.

Nonetheless, with it running right...the bike is very close to being a good all around bike. I think a 144 kit, can possibly make the bike an all around bike for someone that wants to ride anything short of sand dunes. It will single track, motocross, put behind the kids, scream on open 3-6 gear stuff, take on mud, etc. etc.

The best part, the bike is small, cheap to maintain, easy to work on.... and cheap, cheap, cheap to buy.

But you do have to play with it to get it to run right. I hope they come out with one next year with all of the bugs worked out. It seems like Husky filters out all the people who are posers , and keeps the guys/girls serious enough to take the time to set up the bikes and realize the potential ???

JS

Went out again today and the bike ran amazing. My bike likes this set-up:

45pj
4th clip
470m
4.0 slide
PV adjusted to the top
stock PV spring

Holliser, CA...so I think around 600ft to 1500ft (somewhere around there)

I rode with this setting from about 55-75 degrees with no hesitation or bog. It has a strong pull off the bottom and through to the top. It will bring up the front wheel with no clutch work in 2-3 gear. A bit of a loss on top, but very small. I may back the screw off to just above 3/4.

Woodschick, you rode it with a 32.5PJ/450m and 5th clip...and it was running pretty good. With this set-up it pulls even harder off the bottom, not flat at all.

I would recommend anyone having trouble with the bog start somewhere around this point, then go from there.

My reacts better to the stock spring vs. having dual springs. I think it spreads the opening of the PV out too far for the 125cc, maybe would pull with the 144cc.

I plan on upgrading to the 144cc and PWK over the summer, but not because the bike needs it, just curious how much more power this little motor can put out

I will try to post up some video the next time I go out. My camera is junk, but hopefully it will record at least a few minutes of riding.

JS

Do you ride at the MCMA property?

Yes, That was where I was racing and most of my riding is at the club as I work near by.

John

I'm looking at pulling the trigger on a new '09 with the OEM 144 kit. Does anyone know if the TMX does any better with the OEM 144 kit?

For me the TMX and the EG144 kit is working good. No bog and the jetting is stable.

Powervalve springs are the main culprit IMO.The stockers open way too late in the powerband. Feels like a bog. advancing the Ignition timing helps also.

Does not like too much race gas though. more than a 1/3 and then jetting gets sloppy more spooge.

Now, to me this looks like the bolt is near the bottom of the slot. Notice a bit of teh slot is visible above the bolt and none beneath it.

Is this what you mean, adjust it so the linkage is up?

Hi, yes you want to adjust the bolt up. Most people adjust it 3/4 to all the way up. I would start at all the way up, and back it off after a few rides if the bike is running well. The only disadvantage to adjusting it all the way up seems to be a slight loss in top end...but it is very slight. You make up for it with great, linear response from bottom to top....no bog.

JS

Okay, must be having a senoir moment, but given the picture I posted (It's the one Motosportz put up) and the description I read, I'm still not getting it. So, here are two drawings (sorry about the quality, art is not my forte). Which best represents what we are after here, the first one or the second one?



View attachment 5069
First one



View attachment 5070
Second one