I love your videos. Thank you so much I’m a grandmother, trying to support my grandson and I have to learn how to work on these bikes. I am in Missoula, Montana, and you are far far away from me. Anyhow, I thought it would be helpful. If you had displayed all the tools you need before hand and explain the tools that you use a bit better, so I can be prepared to do this on my own.
@@jameswharton3143 it went well.. hardest part was putting the clips back in. My son said, “Dad, it feels different. Like a brand new bike!” Excellent walk through!
Great video to help anyone. Just a few things I'd recommend is replacing all o rings even if they appear in good shape. Replacing the o rings on the expansion chamber too, im sure they all come in the kits. And start with a new spark plug. Happy riding
Fantastic video mate well done. Just got my young fella a new 23 coming for christmas. Going to need a few rebuilds with time will definitely follow step by step
Thanks Andrew. Should be very similar process for the Mini. You will have the Oil Mix bottle to remove and things may be a bit tighter with the smaller frame. All the best
James Wharton have you done any maintenance to the clutch yet? I wonder how many hours we will get out of ours. I have the clutch engaging at a lower rpm currently. I’m guessing that will cause it to wear out faster.
Hey James Great vid As a tech I have to say on these bikes you have to raise the front wheel as if it’s in a wheelie position when filling rad coolant to prevent a air lock in the system. Failing to do this in most cases results in a over heating issue Keep up the good work !
Hey Paul thanks for the feedback! I agree with your suggestion as I have herd of stories about the airlock. I personally squeeze the hoses when filling up and then check the level a few times first ride out. But the wheelie position sounds like a great idea
Hi there. Great video. I have a question… what is the rubber gasket around the spark plug ? I hate the gunk that collects in there and also on the 65. That looks like it would be very helpful keeping out debris making plug changes a lot cleaner!!!
I just fixed my sons water pump, took me 2 hours to get the circlip on without the proper tools, haven't started it in 4 years now and I think I need to change ring's after excessive smoke under load...
Did you have no issue with the bolts holding the pipe on hitting the frame? I m trying to pull the pipe off but the bolt hit the frame before I can get them out. I’m working on a mini though, looks close to the same.
Thank you so much for this video! Curious when you oiled up the piston with 2 stroke oil, should we be using the ATF that we use in oil changes? Or 2 stroke oil?
Great vid mate. Very helpful. Quick question completely unrelated to the top end but, my sons is a 2014 mini adventure and has the washer stack style clutch, do you know if I can retro fit the clutch out of one of these later bikes so I can.adjust it easier? Save taking the clutch out everytime I want to adjust it. And playing around with washer stacks.
Thanks for posting this James! This happened to come right in time for me to do the top end on our 2019 50sx. It would be great to know what the compression was after you did the rebuild if you have that information.
Hey I like the videos, save me a lot of time on the phone. I cannot figure which piston kit I need for my 2019 50. Can you show how to determine which piston cpl to use, 1 or 2. Thanks
I’d love some help!! So jealous how easy it started. My daughters 2021 model just refuses to come start, I changed the plug, filter, full carby clean and it still won’t cold start with start ya barstard in the air box. Any suggestions would be greatly appreciated.
Have you tried standing the bike up in its front wheel with the rear wheel In the air? We had that issue from the showroom with our 2023, apparently it's super common and it just floods some fuel in there to start it dead cold.
Will the position still Go on if the ring isn’t aligned with the divot? Just did the top end and it dawned on me I didn’t double check to make sure the pin was aligned with that divot. Hoping I don’t have to break it back down and make sure
Hola, te sugiero que primero intentes agregar menos aceite. Personalmente corro 60: 1, que es 84 ML por 5 litros. Tengo un video dedicado a Premix Ratios, lo puedes encontrar aquí ua-cam.com/video/Av0DXKBEcT4/v-deo.html
Hello thanks for a great video i just done it today. Do it need to been driven slow for awhile`? i hope not becaus my soon can not drive it slow he is to small to understand that. and i am to heavy.
Hey Aaron it's a good way to check which piston size you require. In my experience I have found minimal wear on the barrels and the pistons are replaced with the same size
As long as you can't feel any burs it should be ok. The side of the piston will not touch the cylinder, only the ring. The shop would have plenty of experience also, im sure they would accept it back if they felt it wasn't 100%
Hey, if you were to replace the O - Ring seals on the bottom of the cylinder head, would you use a little oil to lubricate them, or can they go in dry.
I'm my experience yes. But to be sure you can check the imprint ontop of the existing piston. Of course this makes it tricky as head needs to be removed and the crown of the piston is usually covered in carbon
Hi James I want to change the piston my son bike . When I looked the new parts showed two different pistons. Number 1 and number 2 !! Which one the right? Many thanks
Help me my ktm 50 no been at dealer most season I change stater coil off running o9 sx50 no change it sounds like it hit rev limiter it’s 2019 they did top end bottom end no change took brand new reeds boot and carb off new bike no change changed exhaust no change changed cylinder off 2009 no change
I changed my sons piston today it was running fine before but now after I kick-start it on the stand and lower the bike to the floor once the rear tyre touches the floor it cuts out iv adjusted idle screw everything just can't figure out why.
Hi there in my experience yes a standard AB piston should be fine. Obviously can't guarantee anything. Is a bit frustrating having to disassemble before finding exact measurment so I understand your issue there.
@@jameswharton3143 . Yeah, I don't have them. I gave up and reused the old circlips. They went in so easy in comparison. Hoping they will be ok until the next piston change. Love your videos.
Hey there, technically you need to measure the inside of the cylinder and refer to piston sizes to select with the correct one. In saying that the outside of the cylinder should be stamped with a letter on the carb side. Grab a torch as can be tricky to see. If you haven't done a huge amount of hours you should be sweet to stick with the same piston as the letter
@@jameswharton3143 vertex kit came with three base gaskets in ours- in .005" increments. Tested them and I had the option of .025-.035". Running .030" this time. Friend of mine did his, had problems,. Check the squish and he had .020"!
Hi there check this video about setting the correct squish ua-cam.com/video/P5RTJ1i4oSU/v-deo.html If you do not have the squish tool I suggest using the same size gasket that was removed
Just want to say thank you! I was able to rebuild my sons bike thanks to you!
I love your videos. Thank you so much I’m a grandmother, trying to support my grandson and I have to learn how to work on these bikes. I am in Missoula, Montana, and you are far far away from me. Anyhow, I thought it would be helpful. If you had displayed all the tools you need before hand and explain the tools that you use a bit better, so I can be prepared to do this on my own.
Happy to see I am not the only one that Bleeds while working on these. LOL!!
Yes! From memory I scraped it against the radiator. Thought to edit it out but adds to the realism 🙂
This is great information for all us 50 dads. Just rebuilt the top with this video. Thank you!
Thanks alot for the feedback!
You are a real one for all of the KTM 50 videos!! Big thanks from USA my man!!
Thankyou Sir! You are more than welcome
This was very helpful! I appreciate you taking the time to film this in the manner you did. Replacing my sons top end this weekend!
Thanks Jacob. How did it go?
@@jameswharton3143 it went well.. hardest part was putting the clips back in. My son said, “Dad, it feels different. Like a brand new bike!” Excellent walk through!
Thanks glad it went well
Great video to help anyone. Just a few things I'd recommend is replacing all o rings even if they appear in good shape. Replacing the o rings on the expansion chamber too, im sure they all come in the kits. And start with a new spark plug. Happy riding
Fantastic video mate well done. Just got my young fella a new 23 coming for christmas. Going to need a few rebuilds with time will definitely follow step by step
Glad I could help Andrew. Your going to make some great memories
Awesome videos 👌
We just did our 1st top end rebuild on a 50sx using your video as our guide, very informative and easy to follow. Top effort!!
Thanks Emma!
Another great Ktm 50 video! I just purchased a 2019 Ktm 50 mini for my son. This top end video will help me out someday.
Thanks Andrew. Should be very similar process for the Mini. You will have the Oil Mix bottle to remove and things may be a bit tighter with the smaller frame.
All the best
James Wharton have you done any maintenance to the clutch yet? I wonder how many hours we will get out of ours. I have the clutch engaging at a lower rpm currently. I’m guessing that will cause it to wear out faster.
@@AndrewDeVries211 No it seems to be functioning fine. Running at 8 clicks. Keep changing your oil regularly.
Keep the videos coming!!! Very informative for new motto dad's 🤙. Highly appreciated!!!
Thanks for the kind words 🤙
Any videos on the crank case seal clutch side
thanks buddy, going to be working on my sons TC 50 next week and this video just made the job look so easy
Thanks Eleazar kind words much appreciated
Kudos to you for "recycling" your clean coolant!
My sons bike just turn 122 hours on clock , time for first top end rebuild :) thanks for the video .
Your Welcome 🙂
What size piston did you use after 122 hours?
@@jonesycrew change barrel and piston after that . Barrel was like egg shape
Did you use the AB then?
@@jonesycrew yep all standard , for another 120h i hope
Thank you, too easy
Big help. Thanks for the video. We followed along tonight
Great to hear!
Hey James
Great vid
As a tech I have to say on these bikes you have to raise the front wheel as if it’s in a wheelie position when filling rad coolant to prevent a air lock in the system. Failing to do this in most cases results in a over heating issue
Keep up the good work !
Hey Paul thanks for the feedback! I agree with your suggestion as I have herd of stories about the airlock. I personally squeeze the hoses when filling up and then check the level a few times first ride out. But the wheelie position sounds like a great idea
Thanks for the clear video and instructions. Confidence inspiring!
Glad it was helpful!
Love the vids, just bought my son a new ktm50sx and he loves it. All these ktm50vids will definately come in handy. Any bottom end vids?
I have a dream that you gone do a video on how to bleed the back breaks 😀
Thanks for the vid man I just picked up a 2nd hand 2015 KTM 50 SX senior you the man cheers
Thanks Richo glad it helped
There is a small tool made for installing the clips. If, you perform this job often, you may wish to check it out. Great video!
Please post a link. They're giving me hell at the moment
Which base gasket thickness did you end up using? I know the kit comes with several?
Hey there check out my Squish video, that will show you how to select the correct gasket
Thank you for taking the time on this
You are welcome
Hi there. Great video. I have a question… what is the rubber gasket around the spark plug ? I hate the gunk that collects in there and also on the 65. That looks like it would be very helpful keeping out debris making plug changes a lot cleaner!!!
Top notch video my friend. Excellent job. Thank you.
Thanks Eric glad it helped you!
Your channel has inspired me to lear how to fix my Ktm sx 50 take a look any advice would be great
Thanks Molly looks like your riding awesome!
Really nice camera angles!
Nice clear instructions thank you
Excelent video… many thanks!
Thanks for the positive feedback Chistian
Great video thanks for the help… do you have a video on kickstart repair?
I just fixed my sons water pump, took me 2 hours to get the circlip on without the proper tools, haven't started it in 4 years now and I think I need to change ring's after excessive smoke under load...
That sure sucks! These things can be one thing after another sometimes
Did you have no issue with the bolts holding the pipe on hitting the frame? I m trying to pull the pipe off but the bolt hit the frame before I can get them out. I’m working on a mini though, looks close to the same.
Could you do this without taking the head off? Not to keen on retorquing those head bolt on alu threads... ask me how I know...
hi, how many hours for piston/ring replacement?
Can you please tell me what the ring end gap needs to measure inside the cylinder.
Great video
Thank you so much for this video! Curious when you oiled up the piston with 2 stroke oil, should we be using the ATF that we use in oil changes? Or 2 stroke oil?
Its the oil that you mix with gasoline, not on transmittion.
Yep it's 2 stroke oil
Do you have a bottom end rebuild video? Still yet to try the above on the top end
Awesome vid, thank you!
Always welcome thanks
Great video mate 👍🏻
Thankyou much appreciated
what type of coolant car coolant ok?
Great vid mate. Very helpful. Quick question completely unrelated to the top end but, my sons is a 2014 mini adventure and has the washer stack style clutch, do you know if I can retro fit the clutch out of one of these later bikes so I can.adjust it easier? Save taking the clutch out everytime I want to adjust it. And playing around with washer stacks.
Excellent and informative video. Did you check the conrod for any bottom end play?
Thanks for the video. Does it matter which way the piston ring is facing up or down
Ik I’m late but yeas it does matter it has a “t” for top on the correct way to put it on
Thanks for posting this James! This happened to come right in time for me to do the top end on our 2019 50sx. It would be great to know what the compression was after you did the rebuild if you have that information.
Why do some people recommend to hone the barrel?
Hey I like the videos, save me a lot of time on the phone. I cannot figure which piston kit I need for my 2019 50. Can you show how to determine which piston cpl to use, 1 or 2. Thanks
The number is stamped on the cylinder
I’d love some help!!
So jealous how easy it started.
My daughters 2021 model just refuses to come start, I changed the plug, filter, full carby clean and it still won’t cold start with start ya barstard in the air box.
Any suggestions would be greatly appreciated.
Have you tried standing the bike up in its front wheel with the rear wheel In the air? We had that issue from the showroom with our 2023, apparently it's super common and it just floods some fuel in there to start it dead cold.
Why did the cylinder head need to come off ?
Will the position still
Go on if the ring isn’t aligned with the divot? Just did the top end and it dawned on me I didn’t double check to make sure the pin was aligned with that divot. Hoping I don’t have to break it back down and make sure
Hey Ace, no I don't think the cylinder would be able to slide over if the ring was not in the correct position
Aye mate did ya do a bottom end rebuild
James - do you have the torque specs on all the nuts and bolts for doing a top end change?
Nevermind - I didn’t hear it the first time I watched video
thank you !!!!!!
Welcome
How can you know what kind of piston you need?
how do i know what piston to use? mine says 39/5R on the cylinder but im seeing pistons for 39.48 and 39.46?? and what do the letters mean a/b etc etc
Excuses me what is the stroke on this and is it 10 or 12 wrist pin
Very nice job. Also but the bike in a wheelie position to bleed the air out they can get a pocket of air at the back of block..
Good tip mate, have herd this. Thanks
Did you have to gap the ring?
how long running in time?
Hi,mi KTM 50sx,2013,echa mucho humo será posible el retén del cigüeñal dañado🤔,para la premezcla uso aceite castor 927 ,1 onza por litro de gasolina
Hola, te sugiero que primero intentes agregar menos aceite. Personalmente corro 60: 1, que es 84 ML por 5 litros.
Tengo un video dedicado a Premix Ratios, lo puedes encontrar aquí
ua-cam.com/video/Av0DXKBEcT4/v-deo.html
@@jameswharton3143 ok,eso realizaré,muchas gracias
Hello thanks for a great video i just done it today. Do it need to been driven slow for awhile`? i hope not becaus my soon can not drive it slow he is to small to understand that. and i am to heavy.
Hey Mark I wouldn't stress too much about breaking the new top end in, just don't hold it wide open on the stand or anything 🙂
@@jameswharton3143 Thanks for a fast answer 🙂
Love the video mate, keep up the good work! Just a question.. do you ever need to check piston ring gap?
Hey Aaron it's a good way to check which piston size you require. In my experience I have found minimal wear on the barrels and the pistons are replaced with the same size
@@jameswharton3143 thanks for the reply mate!
We just picked up 2 new Gas Gas mc 50's so will be doing a top end or two in the future. 👍
@@aaronbaird7258 How goods that! Our MC50 has about 6.5h on it now seems really solid
@@jameswharton3143 good to hear mate! They're a top looking bike. Can't wait to set the kids free on them
James - is it normal for a new piston to have small imperfections from factory? i have never changed a piston.
Hey Tyler not really. Where abouts are they? The top will have indented ID marks on it
They feel like little metal bumps when I run my fingernails on side of piston. I took back to shop and they said it was fine. I may be overthinking
As long as you can't feel any burs it should be ok. The side of the piston will not touch the cylinder, only the ring.
The shop would have plenty of experience also, im sure they would accept it back if they felt it wasn't 100%
Hey, if you were to replace the O - Ring seals on the bottom of the cylinder head, would you use a little oil to lubricate them, or can they go in dry.
I would suggest a little 2 stroke oil or high temp grease but not much just enough to find their position easily
Compression test? I can't find what the compression should be in the manual anywhere
Hey Trent about 130PSI is ballpark. I am also unable to find it in the manual
Hey mate, how many hours are you doing before top end Rebuild ??
Hi really depends on how the bikes are ridden but usually between 20 - 40 hours.
Stock low hour engine will always be a "AB" Piston?
I'm my experience yes. But to be sure you can check the imprint ontop of the existing piston. Of course this makes it tricky as head needs to be removed and the crown of the piston is usually covered in carbon
What is a cd piston m8
Hi James
I want to change the piston my son bike . When I looked the new parts showed two different pistons. Number 1 and number 2 !! Which one the right?
Many thanks
Did you get the answer, im on the same right now.
If its the original head you will use AB piston always.
Help me my ktm 50 no been at dealer most season I change stater coil off running o9 sx50 no change it sounds like it hit rev limiter it’s 2019 they did top end bottom end no change took brand new reeds boot and carb off new bike no change changed exhaust no change changed cylinder off 2009 no change
Like what could it be runs fine throttle wide-open sounds like rev limiter
Just a dad that needs help
Replace stator and ignition
I changed my sons piston today it was running fine before but now after I kick-start it on the stand and lower the bike to the floor once the rear tyre touches the floor it cuts out iv adjusted idle screw everything just can't figure out why.
Hey Martin could be normal. Maybe turn idle up and make sure bikes warm before putting it on floor
Do you reckon it Would be safe to order the standard size piston at 60hrs or should I open it up to measure first?
Hi there in my experience yes a standard AB piston should be fine. Obviously can't guarantee anything. Is a bit frustrating having to disassemble before finding exact measurment so I understand your issue there.
Would it matter much if I ordered the ab size and it actually needed the bigger size?
Won't be ideal, personally I would buy the AB and see if you can exchange it if too small
How many hours are you putting on the piston and ring before replacing?
I do about 40h.
@@jameswharton3143 Wut?
I just wanted to see how big the piston was.. watching an engine rebuild is interesting though.
On these bikes are the piston rings sided?
No they are not
Is this the same for a mini?
Fundamentally yes. You may need to take oil bottle off
Oh my God. The @#$$@@ circlips are killing me
Can be tricky. Long fingernails help!
@@jameswharton3143 . Yeah, I don't have them.
I gave up and reused the old circlips. They went in so easy in comparison. Hoping they will be ok until the next piston change.
Love your videos.
I have a 2023 50 mini but i dont know which one to get..the ab or cd?
Hey there, technically you need to measure the inside of the cylinder and refer to piston sizes to select with the correct one.
In saying that the outside of the cylinder should be stamped with a letter on the carb side. Grab a torch as can be tricky to see.
If you haven't done a huge amount of hours you should be sweet to stick with the same piston as the letter
@@jameswharton3143 thanks ill look into it
No squish measurement?
Hey Corey, didn't go into detail with squish measurment as don't believe it is critical. Planning to cover it soon. Cheers
@@jameswharton3143 vertex kit came with three base gaskets in ours- in .005" increments. Tested them and I had the option of .025-.035". Running .030" this time.
Friend of mine did his, had problems,. Check the squish and he had .020"!
By the blood on his finger makes me realize this 50 gave him a bit of trouble lol.
What size base gasket?
Hi there check this video about setting the correct squish
ua-cam.com/video/P5RTJ1i4oSU/v-deo.html
If you do not have the squish tool I suggest using the same size gasket that was removed
Hi mi Friends,how much for all You pay? Gasket kit and pistón
A vertex piston kit with gaskets costs about $140 here in Australia
@@jameswharton3143 ok 😀,arre You australian s0?I AM mexican 🤝
@@mechanicmotocycle3398 Yes I am from Australia 🇦🇺. Hi from the other side of the globe 🌎
@@jameswharton3143 yes,other side ,🤩,🤝, good videos,i AM ready for de new videos
I can not get the circlips in! Err
Can be difficult, try to pop it under your nail and push