Nice video! Just did mine at 250 hours, very little carbon, looked great. Amsoil Dominator at 50:1 works well for me. Rings were still less than .5mm. Cleaned and reset the power valve. Good to go for another 250 as far as I am concerned.
It would be very informative if you said what Oil and Mixture you used. When it comes to Two Strokes we all want to know what others use as far as Our and Mixture....
I have a Beta 300RR with 350 hours. Still good compression. No top end needed yet. No racing on the bike. I only trail ride it in the mountains of Idaho. I have a cooling fan on the bike. I use Klotz 2 stroke oil at 40 to 1 premix. Best 2 stroke I ever owned.
Measuring the compression is a good way to monitor ring wear. But unfortunately doesn't tell you what piston wear is occurring. The majority of piston wear will normally happen on the exhaust and inlet skirts. As piston skirt wear increases the amount of piston rock, or slap will increase, resulting in increased stress on the skirt. Eventually the piston skirt will crack and fail resulting in damage to the head, cylinder, conrod and possibly bottom end too. As such I think it's best to change the piston long before it is likely to fail. Piston wear can be minimized by good engine warmup procedure (let it warmup slowly to operating temp before giving it hard throttle), use a good quality premix oil and keep your airfilter fresh and oiled correctly. There is no easy way to check inlet side piston wear without removing the piston. To check the exhaust skirt wear you can remove the exhaust and look in through the power valve port an visually examine the skirt while moving the piston up and down (put the bike in gear and bump the piston up/down using the back wheel). I made this video showing this method: ua-cam.com/video/AlrcK5FMZok/v-deo.html
Ojalá hubiera algún español haciendo vídeos como este, no entiendo casi nada de lo que dice , pero se le ve muy profesional y controla muchísimo del tema.
It’s a two stroke engine. Oil is mixed with gasoline to lubricate the crank and piston. The oil buns and leaves carbon deposits on the piston crown, head, power valve and exhaust.
It's probably Castor based oil. Castor Based oils always leave the inside of the engine black with soot, it doesn't burn very clean, it is one downside of Castor and the other is Castor oil has a tendency to separate in fuel when stored so you need to shake it up well. The upside of Castor oil is it can withstand higher heat so if you are running on the lean side now and then the Castor will tolerate it more but to be honest any properly jetted soigne should not be getting that hot. I personally don't like using Castor due to the soot problem and the fact is can separate form the fuel if stored, I prefer a synth oil myself.
@@TokyoOffroad That's not too good for a Synthetic oil to produce that much soot like like Castor does. Soot doesn't do any good in the engine and given time it will foul parts and build up on exhaust port and expansion chamber surfaces.. If it was mine Id be looking at some other oil that doesn't leave soot like that. Alternative is it might just be running too rich.
can someone explain how this hour tracking works? When we talk about 4 stroke engines we estimate their life with years. How can an engine last only hours?
My recommendation would be to overhaul the top end on these bikes every 100-200 hours, depending on hop you ride and how fresh you like the bike to feel. At 200H I suspected the ring end gap would be at, or greater than 0.5mm (the Max Vertex ring end gap spec). The top end is relatively cheap and easy to overhaul, so I can’t see much point pushing the intervals longer than this.
I plan to do the top end on my 2019 KTM 250 TPI at 80H (currently just under 40H). I'll be sure to make a video and compare it to my carb model. From what I've seen from other owners, piston wear is higher on the TPIs. It will be interesting to check and see firsthand...
Yes I did. I perform compression tests fairly regularly to monitor for any changes. I didn’t see a a change in compression from the last top end overhaul do was sure there wouldn’t be any gross damage.
I know this is an old video but it’s amazing to see it as a young kid I don’t have the money to shell out every 50 hours when people say they rebuild there bikes and I never understand that stuff very happy to see someone who rebuilds at very long intervals
Ive got a 2018 300exc. Ive been doimg the piston at 25hrs. Is that just way to soon? Also did you notice a lot more power and compression after you did a new piston?
Yes, 25H is way too soon unless you have a problem. The KTM recommended interval is 80H, or 40H if used for motor sport. For trail riding and if you take good care of your air filter 150H should be no problem. There was no significant change in compression after the top end overhaul, although the bike did feel fresher after.
Way way way to soon. That’s the interval I do my yz125 and it’s a single ring engine that I have to live on the pipe with doing anything technical uphill
No, it's a 2017 KTM 250 EXC with a Keihin 38mm Air Striker Short and STIC metering block. I also have a 2019 KTM 250 EXC TPI. I read that the TPI oil injection varies between 70 and 150:1 (depending rpm, throttle position, load): transmoto.com.au/ktm-two-strokes-engine-development/?fbclid=IwAR3wEjFWlynOPPFK5yLUnq6B9Z3dY1n94dzYJH9Cw5tfoVaoQGPcBOzhQVg
What's your experience with KTM 4 strokes? I have a 350 w/100 hours on it, religious air filter and oil changes. Only dual sport and moderate enduro riding. I hope to get lots of life out of it.
Jeff Minnion - I’d recommend checking your valve clearance every 80H (and adjust if necessary) and doing a top end overhaul every 200-300H depending on how hard you ride it. I’m sure you could run the top end much longer, but the 200-300H should ensures it’s performs well and minimizes cylinder wear.
I see your other video shows 295 hours on the bottom end. Thanks for the video. The oil is giving you very good top end life. I think that is what I am going with now. Did those rings also have 150hrs on them? Did you measure the ring end gap on the old rings?
@@TokyoOffroad Wow. The rings in my 2013 250XC at 94 hours had a gap 4 to 5 times larger than yours! I bought the bike used. He ran Amsoil Interceptor at 50 to 1. I am guessing dirt got in. The cylinder and piston did not have scratching. This will be the 2nd top end. My new rings have a .43mm gap. I did measure the bore multi times with a telescopic bore gauge and a micrometer and all measurements were in spec.
The ring gaps are staggered. On the piston there are two ring end location pins on the intake side. The end gaps sit here, slightly staggered. This video clearly shows the location of the pins and also shows the ring end gaps passing over the intake port in the cylinder. May be of interest: ua-cam.com/video/K6gzvgV8uIs/v-deo.html
A KTM OEM 2-stroke top end overhaul kit (piston, rings, wrist pin & clips and gaskets) cost is about $200. Once a year that’s not really much money IMO.
There is no ring service schedule specified in the manual. The manual does specify a piston change interval period of every 80H, or every 40H if used motorsports. OEM pistons are supplied with new piston rings. I made this video regarding piston ring wear in this engine which you might be interested in: ua-cam.com/video/aC-K9r_-lIc/v-deo.html
Great video Mark, very informative and detailed. Good stuff! Thanks ;)
Nice video!
Just did mine at 250 hours, very little carbon, looked great. Amsoil Dominator at 50:1 works well for me. Rings were still less than .5mm. Cleaned and reset the power valve. Good to go for another 250 as far as I am concerned.
It would be very informative if you said what Oil and Mixture you used. When it comes to Two Strokes we all want to know what others use as far as Our and Mixture....
I use Motorex Crosspower 2T mixed at 60:1
@@TokyoOffroad 60:1.. nice
@@TokyoOffroad 60:1 for all conditions?
@@NirHason Yes, 60:1 is all I've ever used in this bike and is the mixture recommended by KTM in the manual.
If you use the Maxim Castor 927
Say 36/1 to 40/1 You will not have the black carbon on your pistion at all. Go video I like.
Great informative video.. Glad to see minimal wear with that many hours.
I have a Beta 300RR with 350 hours. Still good compression. No top end needed yet. No racing on the bike. I only trail ride it in the mountains of Idaho. I have a cooling fan on the bike. I use Klotz 2 stroke oil at 40 to 1 premix. Best 2 stroke I ever owned.
Measuring the compression is a good way to monitor ring wear. But unfortunately doesn't tell you what piston wear is occurring. The majority of piston wear will normally happen on the exhaust and inlet skirts. As piston skirt wear increases the amount of piston rock, or slap will increase, resulting in increased stress on the skirt. Eventually the piston skirt will crack and fail resulting in damage to the head, cylinder, conrod and possibly bottom end too. As such I think it's best to change the piston long before it is likely to fail. Piston wear can be minimized by good engine warmup procedure (let it warmup slowly to operating temp before giving it hard throttle), use a good quality premix oil and keep your airfilter fresh and oiled correctly. There is no easy way to check inlet side piston wear without removing the piston. To check the exhaust skirt wear you can remove the exhaust and look in through the power valve port an visually examine the skirt while moving the piston up and down (put the bike in gear and bump the piston up/down using the back wheel). I made this video showing this method: ua-cam.com/video/AlrcK5FMZok/v-deo.html
I once ran motrex oil and my piston used to have thin flaky carbon on to. I went to the puotline mx9 and dont get it now.
AWESOME --- KTM is the BEST !
ehm TPI 2stroke models??? HAHAHA
You are so wrong lol
I think this is my new favorite UA-cam channel
Thanks! Pleased you’re enjoying the content...
Very good info and you look after the air filter as the condition off piston and barrel
Ojalá hubiera algún español haciendo vídeos como este, no entiendo casi nada de lo que dice , pero se le ve muy profesional y controla muchísimo del tema.
Good video as always ☺️
Looking forward to the measuring video
What is that thing run on diesel or wood? I don't think I've ever seen an engine taken apart that was so black inside
It was coal lol.....
It’s a two stroke engine. Oil is mixed with gasoline to lubricate the crank and piston. The oil buns and leaves carbon deposits on the piston crown, head, power valve and exhaust.
It's probably Castor based oil.
Castor Based oils always leave the inside of the engine black with soot, it doesn't burn very clean, it is one downside of Castor and the other is Castor oil has a tendency to separate in fuel when stored so you need to shake it up well.
The upside of Castor oil is it can withstand higher heat so if you are running on the lean side now and then the Castor will tolerate it more but to be honest any properly jetted soigne should not be getting that hot.
I personally don't like using Castor due to the soot problem and the fact is can separate form the fuel if stored, I prefer a synth oil myself.
AuMechanic - No, I use Motorex Crosspower 2T which is 100% synthetic oil. Mixture is 60:1.
@@TokyoOffroad
That's not too good for a Synthetic oil to produce that much soot like like Castor does.
Soot doesn't do any good in the engine and given time it will foul parts and build up on exhaust port and expansion chamber surfaces..
If it was mine Id be looking at some other oil that doesn't leave soot like that.
Alternative is it might just be running too rich.
Damn! You are making good videos! 👍Thanks from Sweden.
can someone explain how this hour tracking works? When we talk about 4 stroke engines we estimate their life with years. How can an engine last only hours?
What was the wear on the pistonring-grov? if you mess sure between the ring and piston in the grove for the ring.
Thanks, awesome information! I have 2017 300 with 250hrs. When do you think i should do the bottom end?
Archie Leeming probably at the 300hr mark id say to be safe
Through the total hours of service and both top end rebuilds, how has your starter motor held up?
In that 150 hours of service did you re-ring that 150? That is some pretty good life at 150 out of a small bore motor!
Danny Compton - Yes, 150H on the same piston and rings. The rings wear very little on these bikes.
what brand of piston did you install at 150 hours? Also Oil brand and mix? Great video, I appreciate the input.
Thanks for the info, I'm looking for a used KTM this kind of gives me a base-line to go by.
Hi i have exc 300 2017 i ride all the time 1:40- ratio should i start riding 1:60 ratio??
Artis Grietens - It’s up to you. Motorex Cross Power 2T mixed at 1:60 is recommended in the manual
Tokyo Offroad yeah!! i use motul 800 oil !!! Ok when i do rebuild top end then i know😂 how black my piston be!!😂
Do what the manual tells you to do and only that ....1:60 . that's what it is jetted for
Благодарю Вас за работу.
Would it be safe to say that 200 hrs is a generally good top end rebuild interval?
My recommendation would be to overhaul the top end on these bikes every 100-200 hours, depending on hop you ride and how fresh you like the bike to feel. At 200H I suspected the ring end gap would be at, or greater than 0.5mm (the Max Vertex ring end gap spec). The top end is relatively cheap and easy to overhaul, so I can’t see much point pushing the intervals longer than this.
I'd be interested in the tpi vs the carb situation wear and tear if that is possible.
I plan to do the top end on my 2019 KTM 250 TPI at 80H (currently just under 40H). I'll be sure to make a video and compare it to my carb model. From what I've seen from other owners, piston wear is higher on the TPIs. It will be interesting to check and see firsthand...
Did you happen to do a compression check before teardown?
Yes I did. I perform compression tests fairly regularly to monitor for any changes. I didn’t see a a change in compression from the last top end overhaul do was sure there wouldn’t be any gross damage.
Good information 👍
I know this is an old video but it’s amazing to see it as a young kid I don’t have the money to shell out every 50 hours when people say they rebuild there bikes and I never understand that stuff very happy to see someone who rebuilds at very long intervals
Ive got a 2018 300exc. Ive been doimg the piston at 25hrs. Is that just way to soon?
Also did you notice a lot more power and compression after you did a new piston?
Yes, 25H is way too soon unless you have a problem. The KTM recommended interval is 80H, or 40H if used for motor sport. For trail riding and if you take good care of your air filter 150H should be no problem. There was no significant change in compression after the top end overhaul, although the bike did feel fresher after.
Way way way to soon. That’s the interval I do my yz125 and it’s a single ring engine that I have to live on the pipe with doing anything technical uphill
This is not TPI model? What is the TPI mixture % set at from factory?
No, it's a 2017 KTM 250 EXC with a Keihin 38mm Air Striker Short and STIC metering block. I also have a 2019 KTM 250 EXC TPI. I read that the TPI oil injection varies between 70 and 150:1 (depending rpm, throttle position, load): transmoto.com.au/ktm-two-strokes-engine-development/?fbclid=IwAR3wEjFWlynOPPFK5yLUnq6B9Z3dY1n94dzYJH9Cw5tfoVaoQGPcBOzhQVg
What's your experience with KTM 4 strokes? I have a 350 w/100 hours on it, religious air filter and oil changes. Only dual sport and moderate enduro riding. I hope to get lots of life out of it.
Jeff Minnion - I’d recommend checking your valve clearance every 80H (and adjust if necessary) and doing a top end overhaul every 200-300H depending on how hard you ride it. I’m sure you could run the top end much longer, but the 200-300H should ensures it’s performs well and minimizes cylinder wear.
Did you ever put a bottom end on the ktm? How long will I tlast for trail riding?
I'm up to 400H now on this bike. Will probably do the bottom end at about 500H...
@@TokyoOffroad cool. Do a video about it when you do the bottom end 😁. Nice videos
@@daph7017 - Yes, will do for sure...
Cuánto cobras por sacar cilindro de KTM 250 o 300 ?? How much?
WoW, WoW, That is in amazing cond.!!!!!!!!!!!!!!!!!!!!! What oil ? What ratio ? Great Video!!
Allen Evans - Motorex Crosspower 2T at 60:1.
need to state premix and ratio thanks
Mototrex CrossPower 2T at 60:1
subscribed and waiting for the video u promised :)
Kristjan Hočevar - Thanks for subscribing. I’ll plan to make and upload the bore measurement video by early next week. Please wait a little longer...
isn't blowby from rings worn to far
mullaway - Performance was still fine and compression and hadn’t changed from the last change, so I don’t think it was an issue....
What oil and what mix ratio are you using?
Motorex Crosspower 2T at 60:1
@@TokyoOffroad Thanks. How many hours on the bottom end?
I see your other video shows 295 hours on the bottom end. Thanks for the video. The oil is giving you very good top end life. I think that is what I am going with now.
Did those rings also have 150hrs on them? Did you measure the ring end gap on the old rings?
@@grant31781 - Yes, both the piston and rings were 150H. Yes, the ring end gap measurement shown in the video was the old ring (top one).
@@TokyoOffroad Wow. The rings in my 2013 250XC at 94 hours had a gap 4 to 5 times larger than yours! I bought the bike used. He ran Amsoil Interceptor at 50 to 1. I am guessing dirt got in.
The cylinder and piston did not have scratching. This will be the 2nd top end. My new rings have a .43mm gap. I did measure the bore multi times with a telescopic bore gauge and a micrometer and all measurements were in spec.
oil ratio?
Motorex Crosspower 2T at 60:1
This is why I use Vertex I my CR500af. Never Wisucko..
Wisecos last way longer. Forged is a lot stronger than cast
Why is your ring gaps are lined up thought they needed to.be staggered
The ring gaps are staggered. On the piston there are two ring end location pins on the intake side. The end gaps sit here, slightly staggered. This video clearly shows the location of the pins and also shows the ring end gaps passing over the intake port in the cylinder. May be of interest: ua-cam.com/video/K6gzvgV8uIs/v-deo.html
Well, the rings certainly have been gone for ages. You need to start running better fuel in that thing. Very filthy dome and head.
Katooms run forever
My rings on my 300 exc are always around 0.8mm at 80 hours same with mates bikes. We must ride a fair bit harder.
Go hard son!
Or leaner jetting
I’d get a ktm if the costs less and didn’t cost as much to fix
A KTM OEM 2-stroke top end overhaul kit (piston, rings, wrist pin & clips and gaskets) cost is about $200. Once a year that’s not really much money IMO.
"like new, barely ridden, fresh top end - perfect condition. $6700 or trade for new wife"
old sport - LOL
At what hour does the manual say to change the rings?. It can't be 150
There is no ring service schedule specified in the manual. The manual does specify a piston change interval period of every 80H, or every 40H if used motorsports. OEM pistons are supplied with new piston rings. I made this video regarding piston ring wear in this engine which you might be interested in: ua-cam.com/video/aC-K9r_-lIc/v-deo.html