I'm going to show your video to the guys who think they have to change their piston after 50 hours when they don't even use 50% of their bike and they tickle the throttle. Finally someone like you who proves it!
Bro get a 125, I've had my kx125 for years. I've had 450's 250's and all sorts of other bikes. As long as you mix your gas to the right ratio and keep it maintained you can get lots of hours out of it. Not only that, they cost about 1/3 of the dough to rebuild
I did lol had a 2013 crf250r setup perfect for the woods traded for a 2015 yz125 threw the lectron/boyesen combo she’s like a Mtn bike with power it’s great
@@liamhartman7398 Let's say 4T got 1L oil what u change every 10h. 2T got 1L gear oil what you change every 10h So that's equal right? Have you measured how many L engine oil u mix /100h ? I help you. Your ratio is 1/40. So 1L to 40L petrol. 40L petrol is raffle 6-8 h ride?! So you need 15L engine oil/100h 45L/300h where u rebuild the bottom. Now count how much 45L 2T good quality oil and rethink which cheaper.
No, 4 stroke owners be like, wow your already rebuilding a 2020 2 stroke 2 strokes suck pretty bad My crf 150r had a LOT more than 82 hours on the thing and is just now getting a rebuild
@@_T_R_E_V_O_R_ your 150r is a pit bike, if you went 82 hours on a 250F you would of likely had serious issues if not a blown engine that cost more to rebuild than the value of the bike
@@Sleepy.Time. 4 stroke 125cc and under is a pit bike u idiot, a 150r is a youth race bike U must know a lot about bikes 🤦♂️ I'm only 13 so it fits me just fine
@@_T_R_E_V_O_R_ The 150 is not using titanium valves, its not using a high compression piston and it not tuned to produce horsepower over reliability. Anyhow not gonna argue with a child so have fun on your mini bike and get your valve clearance checked before its to late.
Thank you Brad! You are nice polite young man. Way better rider than I am or ever was at your age. I'm gong for the YZ 125X for my KTM300 replacement. The 300 made me a lazy rider. Thanks for offering kits for this bike at a reasonable cost. I wish you the best of luck on your channel.
Thanks a lot for watching Christopher! I think you’ll have a lot of fun on the 125. I definitely prefer it over a 300 for fun riding. I have a sale going on right now. Code “laborday20” gets you $20 off an order of $150 or more. Valid through Labor Day. You’ll save a total of $53 on the freight train package with that 😁
I agree that the YZ125X will cure you of your laziness! But you might miss the electric start, especially if you stall in a tight spot going up a slope. Include in your choices the 150XCW, TE150 and Beta 200RR if you don't want to kick start only.
Marc Bernard 2021 ktm 125 xc - it’s going right after the Yamaha enduro 125x crowd. No tpi. And trail ready with kick and e start, larger see through tank, and lighter than all the tpi’s... it’s the only thing keeping me from jumping on the 125x. It’s priced to compete with the Yamaha looks like. More... but not a lot more.
sorry to be offtopic but does any of you know of a tool to log back into an instagram account? I was stupid forgot my account password. I love any tips you can offer me!
@Gavin Titan Thanks for your reply. I found the site thru google and Im in the hacking process now. Looks like it's gonna take quite some time so I will reply here later when my account password hopefully is recovered.
@@wipperwil I wouldnt trust someone else to work on my bike. I can rebuild and buy parts for any piece of it. Not sure why i would pay someone labor for a a few beers and some hours of wrenching in my garage.
At 5:52, when tightening the powervalve shaft nut, lock the linkage from moving with the tool kit supplied collar (or use a 1/2" deep socket) otherwise you risk bending the linkage.
The exact 'bolt' size (10mm, 12mm, 7/16" etc.) of the socket doesn't matter, you are simply using the outer diameter as a 'stopper' not to bend the linkage as you tighten the nut. The usually supplied factory tool with a brand new bike is an aluminium dowel about 9/16" (14mm) in diameter by 2" (60mm) long. @@RobertDamien8687
Instead of spending nearly 1k on parts you could... -set the float height and jet the keihin. -get the oem head straightened out. -skip the rad valve. And you would have 99% of the performance for 20% of the cost. 2nd, this guys riding is off the chart. Wow.
To start, it’s a mikuni on the 125. I travel a lot and so do many others. That means change in temperature and elevation. I tried doing the whole re-jet every other day thing on my 250x while on the road and that got old on about one day. And YES it runs like poo with the stock carbs when changing elevation. For the head, there’s more to offer than just fixing the squish, it has more coolant capacity and also allows for changing out the dome if you want different power curves. Although the OEM yamaha reeds are pretty good, the RAD valve has a smaller inlet which in theory will increase air velocity and provide better torque. Works well in co junction with the tapered bore of the lectron carb! So yes, you could do all of those things and then have a cold day and your bike won’t run like how you tuned it not would you get as good of cooling which is very crucial for technical riding that I and many of my customers do! Thank you, trying to improve every day I ride!
Have you considered an aftermarket pipe? It could really compliment the modifications you have made. Two strokes are super sensitive to expansion chamber changes.
That's why I love Yamaha there Powerful and Bulletproof which is not something common when it comes with Dirt Bikes I own a 2006 Yamaha YZ250 I once did 121 hours on the thing never blew I decided to put a 325 ESR big bore kit on the bike and trust me it bites back I am also a track and enduro type rider
@@fastride068 I suggest you the esr 325 but please change your jets for bigger ones as the description of the kit recommends you I did 120 hours for testing purposes lmao I own a KTM 525 EXC-f and well my YZ 250 I wanted to test how far I would reach nefore having blew up I did 121 and still ran good I gave up my test and gave her the 325 kit
How long ago was 1988? Hmmm, let me see.. Okay I got it! 32 years. Still running the stock piston and clutch on my Fourtrax 250R. Is that bad? Longlivethefourtrax250r
Leave your radiator cap on when you undo the drain, then remove it slowly and raise the bottle to meet the increased flow ;-) What's your plan with the barrel when it reaches service life, new one, reco or sleeve?
4 года назад
i would have honed the cylinder and leave that piston in,
honing the cylinder just strips off any coating that may be left. back to aluminum on aluminum wearing. I know everyone rebuilds differently but I measure the piston and if it's in spec then I just replace the rings.
This is awesome to see someone going the hours and proving it on vid for us, on his own bike. Vegas Romaniac also did 250 hours on his yz250fx w/ oil changes at 30-40 hours, and sent oil in to get results. His bike is around 300 now still strong. Yamaha's performance + reliability is amazing.
Haha - love all the spicy comments from all the shadetree mechanics... lol Here’s the deal... if you chose and are comfortable turning your own wrenches too then do it and shut up... Everyone that’s also doing it also agrees that the price of admission in taking it on is the price paid for the bike on day 1 and every cost benefit choice for costs to how YOU choose to run and maintain YOUR bike. (PS labour / time IS a “cost” - even if it’s cost from doing anything else). Or feel free to start your own channel... or drop the bike off at the shop and go ahead and get soaked regularly - by someone likely even less interested in the next 100 hours of YOUR riding performance. The follow up video to this one should be an interesting nod to the haters and small engine professors. 😂
not even, u but you should check the valves just to be sure, i have 200-300 hours on my 06 crf450, was ridden by my dad from 2010 to 2016 as a 40+ vet, then we had to do a whole new clutch basket and clutch, and some other minor things, and it was running like brand new, might need to rebuild the carb or upgrade tho, 11 years after a rebuild and thing will still kick a brand new 450s ass in the desert
Maybe this question was already asked and answered. Do you know what your starting compression was when new and just before the top end and also after you did the top end? Compression means a whole lot more to me than hours themselves.
I think they should change the regulations in the motocross so the piston need to last for example at least 100h for racing. The bikes would be 5kg heavier and would last much longer.
Just picked up a 2023 yz125x brand new. I live in Canada and heard the carb has some jetting issues. Any advice on jetting specs outside of getting an electron carb. Once it's paid off I'll look at performance parts! Thanks
I have a 2017 YZ 125 that I have more or less made into an X. I am still looking for some bottom end power improvements and have been toying with the idea of putting a lower compression head and the CDI off an X to improve things a bit. Did you find a considerable difference with the mods you made, and have you heard of anyone doing the CDI change? I also have a 2017 300 XC-W Six Days which I love, but the 125 is so much fun. We ride in the Eastern slopes of the Rocky Mountains near Calgary, Alberta so the trails can be wide open to super tight and technical. I am 6'1" and 195lbs and fit, so I enjoyed riding the 125 last season. Any advice would be appreciated. Great video by the way.
My sons ride hare scrambles. They go pretty go. We are doing pistons at 20 hours and less. Any more than 20 hours has seen catastrophic piston failure. Can't tell why the failure. All stock.
no clue, with proper maintenance, bikes will go for 100s upon 100s of hours of non stop fun, just run correct 2 stroke mix, or just change oil/make sure your coolant is good, and you will never have to worry, i run my bikes till they break, and i havent had one break yet!
Did you check for play on the lower rod bearing? I think I used to replace the wrist pin, and wrist pin bearing and circlips when replacing piston and rings......that would be a few years ago (45)😂😂😂😂.
I rebuilt my ktm 500 top end for the first time and totaled bike 1 week later and fractured my femur, tibia, pelvis, and both wrists lol... about 10hrs of work wasted 😭
Buy a compression tester. Check compression every now and then when you do your routine maintenance. Seems like a lot of guys don’t need to rebuild top end as often as they think they need to.
You kids are SO enamored with rebuilding perfectly good engines! How about just checking the compression..how about doing a leak down test? Heck, I rode the wheels off of a 1986 yz80. I'm talking 1,000's of hours of kid-sized fun...rev'ed to the moon countless times. I finally took the top-end off, it looked brand new. My dad confirmed it with compression tests. Just mix gas with decent 2 stroke oil (at the correct ratio) - it's that simple. If you want to rebuild an engine, get an old lawnmower and have at it. PS - pulling the cylinder off of a two stroke is not rebuilding an engine.
@@hiphopaDIZZL I'm from that era of older dirt bikes too, And he's right. 2 strokes have not changed one bit in the last 30 plus years. Change the oil and run correct mix and you have nothing to worry about. You can go years without ever worrying about a motor failing. Fact!
You can def get more then 2 pistons out of a cylinder i would consider those general wear marks instead of even calling it light scoring, probly can't feel anything with your nail
@@coloradodirtbike5930 I'm not sure what your trying to prove to me buddy, I said his culinder is fine its general wear marks unless he can catch his nail on it. I'm a small engine mechanic no need to go on about ring gap for whatever reason lol
Thanks for the great video! Nice to see the bike held up well. 82 hours our of a 125 top end is impressive. What 2-stroke oil and mix ratio did you run?
was there a performance loss at 80hrs? i have a 125x and im not crazy about everyone saying rebuild at 40-50hrs max. im not ricky carmichael ripping up an mx track and running it on the ragged edge
LowJack187 i definitely aint going to go by the book lol. those are yamahas 'cover our ass/hardcore racing' numbers. i dont ride like ricky carmichael but i didnt say i just putted around either. im gonna see what it feels like at 40-50hrs. i might just do the first top end around then and see what the cylinder and piston look like. if everything looks good and it still runs good when i do the top end ill probably stretch the next top end longer
@@BeRADpiston didn’t even have scoring on it. I just n got a 2018 yz125 and bike has 64 light trail hours. Bought from site proline filter Boysen rad valve and apex head and sxxc and mx dome. Debating on when I should do a piston. I already have the parts but all the money I have spent I atleast don’t want to throw money away compression was around 160.
#fun fact= My 2015 kx 450 has 300 hrs an gets ridden like its stolen, never opened up engine. #the key is I always do routine maintenance (oil change every 5 to 10 hrs.) An I was raised to believe "if it ain't broke dont fix it." I have replaced worn tires, chain, sprockets at usual wear. Rear axle seal broke an got dirt in my bearings bc I over tighten the swingarm axle nut and broke the seal. "My stupidity"lesson learned. #good apple out the bunch
Everyone that rides a 450 talking about how “hard” they ride it but only do oil changes. Not even checking valves or needing to adjust. Well... okay. Then there’s guys changing the piston on a 2 stroke faster than a tire change or an oil change anyway, and they are just as comfortable doing it. It doesn’t really matter. It ain’t broke if it runs... The KX450 is like 50 more pounds and a big rotating mass - no thanks, and 450 guys only need 5 speed gear box... most only using 3 of them anyway 😁 To each their own - but hard enduro (this channels main focus) on an overfed 450. Okay - have fun . A 90-95 kilo (200 -210 pound) bike any day of the week. And the rotating mass of a 450 is fine... until it really isn’t fun trying to execute more precise movements at very low speeds.
Fun fact: if your writing fun fact before bragging about riding a 450 hard and it doing 300 hrs chances are on the trail you don't get over 2nd and the only time it revs is when you go in a straight line so it's not working hard, otherwise it would of blown up a long time ago if you were riding it hard
@@jeremy7818 I'm sure this title is about rebuild an reliability. Not your long story about bike weights..an I'm positive I have just as much fun on my 20lbs heavier 450 then your 20lb lighter bike. Especially the style riding we do around here. Were not into going 2mph an hopping from rock to rock but if that floats your boat so be it..#have fun
If people would not worry so much about their ego and ride a 125, they would feel what MX is about. Too many guys have to have a 450, but don’t realize it’s too much bike for them, plus the extra 30lbs. I will always keep a 125 for those perfect condition days to race the open and vet b classes, nothing better than passing 450s.
lol nice wheelie at the end man... been saving and going to get the yz125x finally got all the money together. in your opinion im riding a ttr230 at the moment (yes i know underpowered trail bike) been riding my whole life, tt3230 is my wifes old bike, I'm 5'9 150 pounds been beating the crap out of the ttr230 and its not really holding up to my abuse on the trails. would the yz125x be a good choice for me? or spend the little extra and do 250x. i ride single track trails mostly. in BC Canada thanks in Advance
After looking at cylinder and piston, do you really think it was time to rebuild it? I'd say you could easily do some 150-200 hours before rebuilding it and would still be good :)
85 hrs and that looks great! Just Did a top end on my sons yz125x at 50 hrs. Ring was worn out. Besides the burnt up piston everything else inside looked great. Not sure why his ring was worn out so quick. But glad we caught it before any real damage happened. Out of an abundance of caution I am going to pull it apart in another 25 hrs and have a look to see if this was a fluke. Sweet video!
I have two KTM 200s and have been considering selling my 2000 to get a YZ125X for more faster open trails. What octane and premix ratio are you running?
hey man I noticed you lived the road bearing with a red fluid? do you run atf in your gearbox? I've been running atf in my 06 ktm exc300 for a while now with no issues
2 strokes are so simple to work on compared to 4 strokes. I guess that's why the have such good resale value. Seems that no one wants to touch a 5 year old 4 stroke because of repair costs.
