1:11

Come along as I diagnose a no start issue on this KTM 250sx, and then do a top end job on her to freshen her up with a new piston. Enjoy!
Link to video on ring end gaps • 1:11 Piston Ring End G...
Link to video on oil premix ... • 1:11 Two Smoker Oil Ra...
Donate Race Fuel link... www.paypal.com...
Thanks for watching!
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[@gunnarpettus1010]

My dawg Tyson’s bike 🤘💯. I already know you gonna have that thing running right 💪!!!

[@UpAllNight91]

Yes sir! Tyson is THE MAN!

[@Jaypnn]

This is great. I don't even have a 2-stroke and I actually just love to hear you explain how it works.

[@UpAllNight91]

Nice!👍

[@hubexergaming8224]

Beavis hates this tool lol...dude i realy thought the same everytime you used it, he gone wild xD

[@UpAllNight91]

🤣🤣🤣

[@anthonygreen6870]

Perfect timing haha last weekend i rode my 2012 KTM 250SX all day Saturday and Sunday with no issues until Sunday evening. Did a couple drags down a straight away and then it bogged down and died. Refuses to start back up.

[@UpAllNight91]

Oh man thats a bummer. Might be the same thing that happen to this one. Does yours still have compression?

[@anthonygreen6870]

@UpAllNight91 yeah theres a good chance its the same! Put a new spark plug in, its definitely getting fuel, measured compression at 185psi. Havent been able to check anything else though. Before it bogged down and died, it felt like it got a sudden burst of power. My guess is the reed broke and it got a lot of air?

[@anthonygreen6870]

I actually dont even know if that's how that works, haha

[@UpAllNight91]

@@anthonygreen6870 LoL, yeah. I'm betting a broken reed. Let me know what you find!

[@anthonygreen6870]

@UpAllNight91 update: There was a gap in one of the reeds. Piston and cylinder looked great 👍🏻. I replaced the reeds with some Vforce, new rings on the piston, new gaskets, took the powervalve system apart and cleaned it, and we are back up and running! Just did a few heat cycles 👌🏻

[@dragoslavpetrovic3616]

C clip oppening is better to be up or down, it is easier to take off, you have something to catch on this oppening on piston. And it can jump off when c clip rotate and catch openning on piston.

[@UpAllNight91]

Hello. Honestly I dont think it really matters where the c clip opening is clocked as far is for holding it in there. Some manufactures even recommend something like 10 o clock or 4 o clock positioning. In the old days they where under built C clips and could jump out (especially on the old RM125's of the late and early 90s) so we use to put them in the 12 or 6 o clock position hoping that would help but since then most every piston comes with clips robust enough to hang in there so matter what, as long as its fully in there. You are correct that its easier to remove them if its clocked so the opening doesn't match the groove cut in the piston. The way I put them in, they go in so easy and always end up with the opening matching the groove. So I just leave it there and only worry about spinning the clip some to get it over the opening to remove when its time to remove it down the road. Its quicker and easier for me and been doing it like this for years with no issues of them coming out on a running motor.

[@billjohn2707]

Love the videos brother! Can you do a video in depth explaining how throttle position sensor works and power jet on yz250? I think a lot of people get it wrong and I don’t quite understand it myself thanks.

[@UpAllNight91]

Thanks. Thats actually a good idea. I will do that. It will take maybe two weeks or so to put it together but yeah I need to check all that on my current YZ anyway, might as well do a video on it. Thanks for the suggestion!

[@billjohn2707]

@@UpAllNight91 great to hear brother! I was researching it myself and finally kinda figured it out but still don’t understand the power jet or any of it fully lol. But I found some forums from 2006 and you were posting on it. You been around brother haha

[@UpAllNight91]

@@billjohn2707 Oh yeah, I use to hang out in them forums a lot.

[@jonahreimer7920]

great video very helpful,i’ve recently bought a 2018 Husqvarna Tc250 has 65 hours. Im going to do a top end soon and i had no idea about the different size base baskets so i will most likely measure the old one before buying the new one so i don’t have to get all 4 sizes. Also how many hours did this ktm have?

[@UpAllNight91]

Right on. The bike doesnt have a hour meter and Tyson doesn't know how many hours are on it but I'm sure its like 100 or more. The piston was ran way to long but it survived so thats good. When you measure the gaskets be sure to also check and see if KTM used two gaskets to get the thickness needed. They often do that.

[@ssse3123]

Should get new pants 😅They are also due.

[@UpAllNight91]

🤣🤣🤣 I know right! I'm looking like a bum in the shop. Its them dam knobbies that keep ripping my pants lol

[@hughiemaceachern5282]

I wouldn't put Wisco piston go stock vortex

[@UpAllNight91]

The standard vortex cast piston is good but a forged piston like wiseco or the vortex race piston is surely stronger and better for track use.

[@hughiemaceachern5282]

Ktm 4 strock seem to out last other's

[@tndeere]

Is it just me or does KTM power valves seem over engineered ? i have a bench buffer with cloth wheel on one side and Scotch -brite pads on the other side to clean up stuff like that power valve

[@UpAllNight91]

Its a little but so is the YZ250 really. Both are kinda complicated compared to like a YZ125. KTM offering so much adjustment though is what allows them to get screwed up if the guy working on it doesnt know what hes doing. Where the YZ has no real adjustment but doesnt need it anyway, it just works. Bench buffer is a good idea actually.

[@ConnorMclaughlin-n3i]

Hi I’ve got the exact same bike as this. I went on it last Sunday was running perfect I pulled the bike out today and it won’t start So I pulled the spark plug out and the end of the plug was black. So I put a new spark plug in and it still won’t start. Any help would be appreciated Thanks

[@UpAllNight91]

Oh bummer. Did you check to see if its making spark? I would start there is see if the ignition is making spark.

[@ConnorMclaughlin-n3i]

@@UpAllNight91yep it’s got a spark and fuel is getting to carb. Compression feels good but I guess I’ll have to buy a compression tester and see what it is. I’m not sure what the previous owner ran the ratio at. I’ve only had the bike 2 weeks he said he didn’t use the bike for over a year it was just sat in the garage. i ran it on 60:1 like the manual says do. Could this be a problem if he’s ran it at a different ratio. I’m gonna have a look at the carb I feel like that could be the problem

[@UpAllNight91]

@@ConnorMclaughlin-n3i Ok. And you checked the reeds already? Changing ratios dont hurt anything so I dont think that would be the case. I would check the reed petal and also make sure the bike is flooded badly.

[@Palmdalebandit_]

IMO ktms used to be pretty junk until 5-6 years ago. Stuff like the way that cylinder wobbles

[@UpAllNight91]

Yeah, trick bikes with some trick parts but they also seem to cut a few corners here and there for sure.