125-200cc 09 Wr 125 Bog/Performance Solved?

[rockdancer]

I think to really know if the TMXX can perform as well l down low as the PWK youd need to take both carbs out to a tricky hill - and do the same run up the hill using similar techniques and swap back and forth
I just know the PWK has reduced my urge to get the 144 kit - but I'll still be getting it

 

[Vinduro]

The TMXX performs well at low RPM and also at High RPM but in the middle it downright sux . Just couldn't get it to perform right. Either way lean or way rich.

 

[rockdancer]

Yes - Its harder to keep on the the pipe with the TMX - falls back in to a power lacking bog
I dont think the issue would be as bad with a 250 and Id probably prefer the Miknuni
Its the engine design and the carby combined
Get on a yZ 125 for example and at half throttle it will lift the front wheel
I always struggle with getting the front wheel up without plenty of clutch or top end of power

 

[dartyppyt]

Don't know what to tell you guys? My TMXX is tuned to a 09 WR125 with the RM needle/Walt's spring kit. It was so bad that I almost sold the bike and bought a YZ 125 with a TMXX on it.

I can do a trials putting around wheel stand with just a whack of the throttle and have an awesome mid range and one heck of a top end. I can bring the front end up about any time I want with just the throttle. I couldn't get this with the PWK. It's there, just not going to put $300 dollars in the PWK to find it. Any time I race and get up against another 125, I leave them on a straight. The only one I can't pass is the new KTM 150. Guys ask my after the race if it has the 144 kit now. I talked to a father/son, they have a CR125 Honda. I let the boy ride my WR125 and he loved it compared to his CR. I bet they will be going to Hall's this winter to buy one. I even wrote down my settings for them because they brought up the B word.

We have done several others (125's) and they are getting results. I didn't tune the TMXX for a 144/150/167 so It is uncharted territory for me. Look at the title of the thread. I don't want to get bashed for taking my results for a 125 and basically sticking them on another, different sized machine and then it doesn't work. All I can do is guess on what to do from across a computer and try to help. It won't be till spring till I get a 144/167 cylinder bolted on and I am even looking at a possible 151 mod. Right now I am inside the cylinder doing my thing with air tools. That will even change things vs stock. It could very well be the PWK works better for a 144/167. I won't know till I start riding and throw my leg over it.

Plus with using race fuels, there is a difference as well. My 250 RMZ had different jetting from pump gas with octane booster vs 110 octane/ pump gas mix vs VP race fuel. You'll just have to find what works for you and what carb suits your needs. Would make a good 144/150 tuning thread.

Thanx!

 

[crille74]

My runns absoluley great whit the rm needle, absolutley no bog or enything, pulls great from bottom to topp whit the TMXX

 

[Vinduro]

I wonder why there are so many difference results from the same setup. I thought for sure that I could get the same great results that Darty got. My PWK setup is far from perfect, it is just closer than I was with the TMXX. It is that Mid range bog or blubber / hesitation that is the problem . I am talking about 2 different problems. A bog is a lean condition and the blubber / hesitation is a rich condition. There just doesn't seem to be a happy medium. From what I hear that there is no consistancy from bike to bike on jetting on these bikes. Hey, All we can do is keep tinkering. I do think that Darty has gotten the issue narrowed down and I recommend that anyone try his recommendation before changing carbs.

 

[LawnDartMike]

I tried the RM needle on my last ride and it definitely helped the mid range flat spot but not as much as the PWK36 did. I will try two other RM needles come spring and see if they work better. For now the PWK is going back on - with the CEL needle it runs so crisp from idle to the pipe that it is hard for me to ride the TMX. My only problem is the transition from the needle to the main blubber (PV?) with both carbs. I would like to go another step leaner on the main but I don't know since my plug chops are light brown (almost tan) and I like to stay on the rich side of things.

There are so many variables with PV settings/springs, altitude, humidity, fuel, pipes, 125 vs 144, carb manufacturer/size, etc., that we will never find a one setup that fits all. All of the given information is just a starting point to get you in the ball park.

 

[pvduke]

hint: when dialing in jetting, dont go/do it on a ride. do it on flat ground and get very scientific with it to eliminate variables. make sure your machine in perfect in every respect.

if yer blubbering in the middle, move the clip up one. if yer close to maxed out on the needle try a leaner needle and start over in the middle one notch down (richer) if you dont wanna change yer main. be VERY careful when leaning out w/ the needle. motors get leaner when hot.

 

[tommytwostroke]

My runns absoluley great whit the rm needle, absolutley no bog or enything, pulls great from bottom to topp whit the TMXX

How did it run before the RM needle? What was your best setting before?

Tommy

 

[crille74]

How did it run before the RM needle? What was your best setting before?

Tommy

Big bog in the middle, no power at al in the mid now it pulls great from bottom to topp
I dont remember the setting before, did try the most.
The rm needle works great, it is a new bike.
The stock Pipe sucks big time to, my HGS 144cc pipe is great but tot smasched in stone, but a new is ordered from Holland.

 

[tommytwostroke]

Thanks crille74.

 

[Vinduro]

Has anyone tried the 35mm carb on the 125 / 144 / 150 ?

 

[LawnDartMike]

I've run the 36 PKW and like it. Haven't heard of anyone trying a 35. (It's not the size, but how you use it!)

 

[water racer]

I thought of trying a 33mm or 35mm from a KDX, but decided the airstryker feature of the newer carbs would give the best of both worlds.
I am using a 36 PWK from a KTM 250 and it is working really well.
GP

 

[Vinduro]

Has anyone checked out the jetting and needles on the Yamaha YZ125 ??? It uses a TMXX .

Dwight

 

[MattR]

Has anyone checked out the jetting and needles on the Yamaha YZ125 ??? It uses a TMXX .

Dwight

Here are some discussions on the YZ125 needles:
http://www.cafehusky.com/forums/showthread.php?t=2058&highlight=yz125
http://www.cafehusky.com/forums/showthread.php?t=8108&highlight=yz125

Here is the link for the 2008 YZ125 service manual:
http://www.yamahaownershandbook.com.au/lib/download.php?f=1C3-28199-33.pdf
The carb tuning section starts on page 148 (section 7-1 to 7-5).

 

[dartyppyt]

I checked them out when working on the 125 and felt their diameters were close to the Husky. I thought it was as step in the wrong direction. I may be wrong.

Husky's had the older TMX in a 59/60 ish needle. The older TMX likes a leaner slide than the rich 3. RM was 2.60 -64 on there's' and 5 slide. That's why I went that way to feed fuel. I also researched the KTM's.

I do have a hunch? Looking @ a KTM parts fiche for an 04 125.

KTM uses a 69 needle and 55 slide for the PWK/125SX (Richer needle and Richer slide).

KTM uses a 72 needle and 65 slide for the PWK/125EXC (Leaner needle and Leaner slide).

Also, they have a 60 slide available.

Is this why the PWK is loosing topend with the 70 slide, is it getting to lean?

My next move was to order a 50, 55, 60 slide for PWK 38

Start with high 60 ish Diameter needles and work down. I was going to buy all the KTM needles for 125SX.

I think if you hit it just right, this will be the best carb, by far, indefinately. It takes time and money,though.

I would also send it to RB designs. Carb divide it in the front and also the rear.

http://www.ktmpartspitstop.com/pages/parts/viewbybrand/13/KTM.aspx

Also, The RM we had, we put shims under the spring to delay the powervalve to hit more around 8,000 RPM. I read the KTM liked the powervalve delayed in I think in the high 7900's. The Husky 125 also likes the delayed hit on mine.

I also stumbled on a couple of things. Why is the 06 powervalve spring stiffer than the 09? I won't know till I test them? Same part #? Is this why some run good and others don't off the bat? Did I get a bike with a lesser tensioned spring?

I also have a hunch inside the 09 Cylinder but won't know till I do some mods to it and get it on the 06 engine to try.

 

[Vinduro]

Year & Bike Model = 2011 WR150
Carb = 38mm Keihin PWK AS
Pipe & Silencer = Stock pipe / FMF S/A silencer
Other engine mods = Exhaust spirngs Stock / silver.
Premix ratio & fuel type = Maxima Super M , 100LL AvGas / 93oct non Ethanol pump gas mixed 50/50.
Temperature range (deg F) = 30 - 40F
Elevation (feet) = 500
Main jet = 178
Pilot jet = 40
Needle = JD Blue
Clip position = #4
Air screw setting = 1.5 -2
Slide = 7.0
Conclusions/Results = Works well. Got most of the mid range bog / hesitation out. Haven't ridden enough to see how much less spooge there is at exhaust junction.
Seems that I have been trying to stick with the recommended main and pilots too closely and that has been making it bog with too lean a needle and setting. I was able to start with 3 kicks in 25F degrees when cold and get off choke in only a few seconds. Still had a slight cold bog for about a minute, which is what it is susposed to do. I came down from a 185 main to a 178 which seems good so far. I might even have to go to a 175 when hotter. I still feel that the carb might be too big for a small bike.

 

[Vinduro]

Gonna try the 175 main at next race. That should be all that is needed to get all the bog out. Most is gone already. I am also talking with James Dean about jetting a 35mm to test. The 38mm is a HUGE carb on a small bore bike. If I loose a horse or so on top but gain it at bottom and mid , it will be worth it. Trying decide what needle to use. My 35mm already has a 158 main and a 42 pilot. It has a #5 slide. It has a N2OM needle. I haven't a clue to what that is. I think the carb was on a ATC250R before I bought it.

 

[water racer]

I have a 36mm pwk with a nozf from a ktm, 175 main, 35 pilot. This is a richer needle than JD blue. Runs pretty good.
GP