125-200cc What does a stock 125 run like?

Trying to get a baseline of what an older STOCK 125 should run like, in optimal tuned condition.

I rode mine yesterday for the first time down our private road and I honestly can't tell what to expect being my first 125, but I don't believe it was anything like this one below in this vid.

I think mine needs fresher/better gas (prev owner said it was a month old), and some jetting changes, which I believe are stock, but still need to crack that thing open to check. I'm about 600ft elev at this place, but plan on riding between 3-6k ft whenever I ride it.

Anyhow, if you have a link to any vids that depict reality of what a healthy stock and older 125 should run like, I'd love to know what I should be shooting for! Thanks!

That vid is a nice running 125 with a good rider on it and riding it like you need to ride a 125 to get the most out of it. Is this your first 2 stroke or small bore 2 stroke. That bike sounds just like my wr165 with my lectron running good. What a great place to ride wonder where that is. My stock 2013 wr125 ran ok stock but after I leaned out pilot and main one jet size big difference and sounded and rode like bike in vid. If you know somebody that is good at tuning a 2 stroke could help a lot.

A 125 you let it scream like a scalded monkey(no mercy ) its all your pleasure and smiles

you make a simple driving error and you will almost drop to a stand still ( the bikes revenge)

you will become a better rider with a smile on your face (what more to wish for)

Robert-Jan

Yup youve gotta be in the top third of throttle at all times to make any progress and you miss a gear change you better be quick to drop down lower an get back on the gas, they punish your mistakes not much torque to cover bad timing/lines.
Like stated stir the gear box and alls fine bringggdingdingggg brawwwwwwaahhhhhh

they are correct on the revs
to competitively ride a 125 you should start with tap dancing lessons

You can see in vid where rider is going around a deep big loamy berm and bike keeps falling out of powerband the rider keep slipping clutch 3 times to keep bike in powerband. Maybe should have just dropped gear on first slip and just holder wide open but that's riding a 125 2 stroke and judging all the time what gear will work the best for speed and condtions. 2 strokes make you a better rider.

SMALL 2 strokes make you a better rider
you are right a downshift would have made much more sense than trashing the clutch

With a bit of fiddling and a carefull setup a Husky 125 can be made to pull from zero to screamer and has more low end power than a 125 should rightly have.
Spent a bit of time sorting out my mate Trigs one and its a cracker.
Excuse the crap riding but its the only vid I have of his - Runs good bottom to top with no steps along the way to speak of.


View: https://www.youtube.com/watch?v=pRWtJShnKy0

What gears do you have on the bike now? It's amazing what a 125 will do if your gears match the riding conditions.

Great feedback guys.

Pedec, had 20+ bikes over the years, this is the first small bore 2 stroke (full size d-bike). Definitely new territory for me. Feels like I'm starting all over again to be honest. Ok, so that vid def depicted a sound running 125, ok, cool.

RJ, yeah, I get that feeling I tell you. You ride the bike on edge so to speak, always in that upper rpm range since there doesn't seem to be any power anywhere else with it stock and that when things happen, haha. I can see how all of a sudden I might be getting hurt now as a rider, not sure I'm welcoming that

Juicy..Yeah, def noticing that quickly. Just coming up my driveway, it's a very steep incline and I had to go down two gears, whereas any of my other bikes just grab and go whatever gear you in. This thing is going to be trickier to ride, and I'll def have to ride substantially smarter compared to what I get away with today.

2Premo, I wonder what I would be better at?

Johnny: Thanks for the vid. How is the midrange on that particular bike. It seemed a little off compared to how it transitioned so quickly into the top. Or am I not reading it right, the mid is solid on that 125 too?

Ida: I'm thinking my 125 is 100% stock, including the jetting, so when I just checked gearing, 13/50, which is stock according to manual. I think the only aftermarket thing on bike is Renthal bars, that's it. I need to start pulling stuff apart on this bike.

In the meantime, now I'm getting a sense for how it ought to run. From the sound and looks of it, these things have near zero bottom end, just a little midrange and a lot of top.

Trigs bike runs a 36mm lectron and has a DEP pipe that actually comes from a wre/sm model that if anything takes a bit of top end away, Also has a stiffer powervalve spring fitted and thats about it as far as mods go, Oh and a 1/4" thick reed spacer that I made up ages ago while just playing with ideas for my bike - seems to smooth the whole curve out, For a 125 this bike is a cracker and as I stated it pulls from zero to top really smoothly but is sneaky fast you can see how it holds its own with my 165 when full chat but then again I am a bit fat old slow one eyed turd lol, Most people who have ridden it say it not a 125 and must be big bored but its not and Trig actually prefers it over my 165 as he finds it less tiring to ride at his ripe old age in life.
Gearing varies from 13/51 to 14/51 depending on where we are riding / racing

Edit Anyone who notices the sound of a hanging idle it was caused by fitting a light return spring from lectron and not a lean condition and was cured by rerouting the throttle cable.

If its not running real well we seem to all head for jetting but we can overlook how fresh the top end is .
I would be checking compression and possibly pulling it down and fitting a new ring and/or piston .
Depending on the gauge you should be over 140 psi.
I can imagine it hasn't been done for a while.
Does it start easy and sound crisp ?
My 165 want running well and it turned out the rings were well beyond the recommended ring gap .
The best upgrade for $ I did on my 08 was fit a newish 2012 top end / cylinder . They have a better design and can be picked up quite cheaply .

Id also be checking the muffler packing .

I was running 12/52 gears and it ripped,top speed speed was only 45mph,great for single tracks though. Now with the 165 I'm running 13/52 and it's a monster,Ha!

Thanks Johnny for the details. Ok, mine will def be different than, with the stock carb, etc.

rock: Bike only has maybe 30-50 hours from what I can tell total since 1999, but I when I start cleaning everything up and going through it like I would any used (new to me) bike, I'll also check the compression too, just to know. Doesn't sound that crisp, but I think that's jetting, fuel, and possibly the carb not being cleaned out as well as it should have been from sitting since 05 more or less. I thought the old cylinders worked well too? Muffler packing will be a no issue, as the FMF silencer is coming this week.

Starts in one kick cold and hot, well at least where I'm at, elevation wise being around 500-600, and the temp has been around 60-65F when I ran it.

Again, the gas is one month old CA pump supreme, so that's not fresh, and not sure on what they used to mix with or mx ratio. I will dump gas and start all over. I was going to run 50% Sunoco 100 octane and 50% 91 Supreme, so basically 96 octane. Will that screw with jetting any, or will it just be fine?

I have a few orders coming in from MotoX and Halls, so Ill ask Halls to send a few main jets and a 30 pilot for this older TMX. I'll need some wiggle room. According to the jetting specs in the manual, should be at a 380 or 370 main and 30 pilot for 3-6k ft where I'll ride it.

Ok, I need to go buy an RM needle of some sort too, right?

Ida: Yeah, gotta keep some speed, for when I do ride open high desert. But I think the bike will spend 80% of it's time in the local mountains, so some single track and some wider trails...so only so much speed is needed. So, need to be somewhere in the middle, gearing wise. I bet that 13/52 with a 165 is a beast...you could easily bring it down some in the rear and it will still pull it, haha.

easy fix, 12 t front for single track, 13 for desert chain won't be an issue, couple minute change of sprocket

If its done around 40 to 50 hours its probably due for a ring IMO
Real easy to work on top end - after you get used to power valve assembly ( not hard )
380 main and 27.5 or 30 pilot should work
Id clean out carb and check needle number and setting
Dartyppt said RM needle doesn't work with older carb

When it comes to let a 125 husky sing THIS is the video to look at!



View: https://www.youtube.com/watch?v=CH6cfktd_XA

Yup thats the sound of a happy trapped bee

2Premo: Yeah, that might just do....

Rock: Took your suggestion. Just added rings and the top end gasket set to my latest shipment coming out to me. Also, 390-370 main jets on the way, along with a 30p. Hopefully I don't need the 27.5. Will do, yes, carb will be thoroughly cleaned and gone through and Ill document needle and position.

I talked to the PO via email yesterday, it was ridden only in La Mirage and Dove Springs, which is exactly the elevation I am shooting for 3-5k'ish. But I'm unsure the bike was actually dialed in for the elevation, they may have just rode as is. But yes, I'll start with that jetting after I get the rings installed/broke in and try to get the needle dialed in. Yes, just read about 3 hours of jetting threads over the last few days and found out that the RM needle only applies to the 09+'s or something like that, which you guys call the TMXX to keep them separate, as they don't have a rectangular slide. Is there another needle that works better than the factory needle on these older TMX's to your knowledge? I didn't see mention of this, other than using the more exp jetting kits out there.

Thanks Miez..... I think Juicy summed it up best, since that's exactly how I heard it....happy trapped bee....haha

I think my 06 and 08 WR came with 27.5 stock
Being hotter here the smaller pilot works good - as it may in higher elevation .
The main jets also like to be leaner on older carb than newer - 380 should be ok - I wouldnt go any smaller . 390 or 400 with a CR ignition.
The factory needle was good - I like the flat slide carb,
I did all sorts of things with my 08, PWK carbs , big bore kits , pipes but just before I sold it I put a new 2012 125 top end on it and it ran great with standard carb
No mid range bogs at all .
Didn't want to sell it ..
If you want a bit more meat though a big bore kit is an option . But if you hold it flat you shouldn't need it