In response to the chain being loose after every session, just wanted to share my experience with that & that is I used to have this problem when running an OTK kart with an OTK engine mount. I fixed this issue by running a chain that was just long enough that the left rear corner of the engine mount was clear (forward) of the chassis weld on the inside chassis rail. As soon as I did this the problem was gone. Before I discovered this fix, I would tighten up the engine mount clamps to the point of nearly stripping the treads, have the stopper bolt on the chassis hard up against the engine mount & yet the chain would still be loose after 1 race. It’s because the mount was sitting on the weld & despite all chassis being welded in a jig, not every weld is identically the same so all you need is a slightly higher weld in that one spot & if your engine mount isn’t sitting flush with the rest of the chassis rails that’s when you’ll have this problem. Cheers, Apples
Hey Apples, thanks heaps for the feedback. the engine mount should have a small relief on that side to clear the weld. if your engine mount doesn't have that on it, you can grind/cut/mill a relief on it so that it clears the weld cross pipe. hope that helps. dez
I did a two year stint kart racing at club level in a rotax max about 12 years back. I found it super frustrating and kinda overwhelming with the amount of knowledge required to learn how to setup and re setup the kart and also to learn all the tricks in racing to even come within 1.5 seconds of the leaders. I wish I had found a resource like this back then! All I could find was a few books. I’m now looking at getting back into karting now and finding the wealth of knowledge in your videos awesome. It’s all making so much sense now why I could only get the kart running well a 1/4 of the time. I really had no clue what I was doing…. Instead of wasting money on tyres practising and racing to just gain and solidify bad habits maybe the better plan is to spend a little more and invest into some driver training to get the best out of those expensive tyres. Cheers really enjoying the content.
Great Vid Guys! A few things that may help some people out. First off in X30, I find EGT helps tremendously as on the Tillotson Carby's you don't have the ability to change jets, and adjusting the high and low needle just a few minutes makes a huge difference. Second O-Ring chains are much better in my opinion, I struggled a lot with chain stretch and the O-ring chain eliminated that. I know many people believe it robs HP, but from my experience, any losses are made back by the fact that the O-ring chain lasts much longer and needs less maintenance. Finally, I think that anyone who wants to start Karting regardless of age should go out and do about 3 days of testing/practice in a true race kart, not a rental. You will get a much better understanding of how things work on top of the fact you can really decide if it's something you want to pursue. Many tracks offer Rotax and X30 Kart rentals and a lot of teams at least in the States offer test days. I've seen people invest thousands just to conclude they do not want to race and are left to sell their karts at a loss. I do strongly agree with getting a good 2nd hand Kart at first so you don't have to worry too much about keeping it in pristine shape, you can find some one or two race old karts for thousands off as teams sell them after a couple race weekends!
@@PowerRepublic Hey! It depends, on a practice day I don’t go higher than 1200-1225F (650-662C) During a race if I need some extra push of the corner I lean it out a little and it may go to 1250F (676c) I’ve had it go to 1300f (704c) for a brief moment when testing but it never hurt anything. But in general anything around 1200 has worked well for me. The Iame jetting app calls for 1175 f (635c) on average but I’m in southern US so much like Queensland it gets to over well over 100f (37C) and quite humid in the summer, I don’t know how much ambient temp affects EGT a lot but 1250f has been just fine for me!
Good one Dezzy, Old man Na, I remember you as a young tike when I sold you guys kart stuff, and I'm still racing karts. On a run of 3 straight podiums across 2 different classes atm, and the last one was in a red OTK that I had not seen before race day. Keep the vid's coming.
I have a RL leopard and am looking for where to find parts and a top end rebuild kit. Where do you recommend I buy them(I'm in WA). Also should I save up for an x30 (for the tag125 restricted class). Also thanks for answering my other question 😊
Hey D, thanks heaps for tuning in. the X30 is an excellent engine for TAG Res. if you can afford it, get one if you really want to hustle in class racing. otherwise get the bits and fix your RL and go for it
Hi, I was wondering if it is normal that with an o-ring chain it seems that the the axel doesn't spin loose like with an non o-ring chain, I believe that the o-ring chain has longer longevity but does the engine loose power through this much more dragging of the final transmission? Also it looks like the chain is a lot wider and very close to the clutch drum, does this may affect the life of the clutch drum itself? thanks in advance PS Your channel is the best!!!
I have measured it on the dyno and the track and it doesn't change the power output or the lap times. If you are still worried use an O ring for almost all your karting and switch over to the non o ring chains as consumables for very important championship races.
it's actually weird, I keep getting the same recommendation for different weather conditions. I went to the kart shop at my local track and asked for the recommended jet and the guy shook his head and said nope, get this one. I said blah blah Rotax app told me this. He just replied mate I've been doing this for 30 years trust me 😂
Not really. The bottom end power normally drops away a tiny bit. But if you are using them in Aus summers when the day temp is over 35 degrees, then good chance they will run into the low 70’s
Also for mitigating water temp on Rotax karts would Redline Water Wetter be a viable option? I have known the product to help supercool the water quite a lot.
@@Jmasta7 I second this, on top of a decrease in temp it also helps a lot with corrosion. I always use distilled water but I’ve experienced some corrosion due to humidity in the past. Since it doesn’t get below freezing here I leave the water and the water wetter in the engine and I find it stays cleaner than if I would have drained it and left it empty, less rust and oxidizing.
Hi there great vid as always, I just have a question on my senior max evo engine. I’m running a 120 main jet but there are some days the engine will rev all the way to 14000 and over goes really well, but then 1 week later it doesn’t. I thought it was my power valve not cleaned up etc but this week it only went to 13100 rpm. Is this just jetting?( There is no lean popping sound generally pulls well) Thanks Sam
geez, 13k is low. nah the PV are normally fine if you haven't got it stick or in upside down. maybe just double check your carby, needle and seat and float level.
Hi Derek There's a thing worrying me and that is how hard I should tighten the two bolts holding the Rotax Max engine? It happened once that the engine came loose during a session, and after that I tightened one of the bolts to hard so that the bolt was spinning and a friend helped me with a reparingkit to fix it. There must be a recomended newtonmeter number for the bolts holding the engine right? It will help me a lot if you could help me with this, cause noone I've asked at the track or even at the local store seem to know. I use a pen to mark the bolt how it's tightened but it does'nt feel relaible. Sorry for my bad English :) best regards from a big fan/ Jesper
Quick question in regards to rotax engines, is there a serial number to tell me exactly what year and model my rotax is? Have a said non evo with all the evo upgrades. Thanks in adavnce.
I just got a Very Used, New to Me 2011 Kosmic, I got it mostly in pieces, I've got all of the major Components, previous Owner cut some tabs off for some reason, That being said, What is the tab at the rear of the inside Axle Cassette that faces left?? What mounts to it??
@PowerRepublic Thanks Dez for the reply, I figured it out, my kart is a yz/cr 125 shifter kart, that being said, it appears on these the rear sprocket is on the inside of bearing hangers, so it's a chainguard mount, just a through hole, no threads. I'm New too all of this and just learning all of the engine types. Learning alot from You're Videos, keep them Coming!
⚠️⚠️⚠️ actually, the Rotax manual itself (operating instruction FR125) says 65° as the optimum coolant temp. 45° being the minimum and 85° the maximum. (In Celsius)
@@riccardoarici i've been racing in italy for 11 years my training go kart has a rotax max engine for reliability, i know this engine very well. i can tell by driving that 55°c is faster, especially when the piston has a lot of hours on it if you run hotter the lack of power it's very noticeable. but i guess that if the manual suggests 65 then it's better for engine health
In response to the chain being loose after every session, just wanted to share my experience with that & that is I used to have this problem when running an OTK kart with an OTK engine mount. I fixed this issue by running a chain that was just long enough that the left rear corner of the engine mount was clear (forward) of the chassis weld on the inside chassis rail. As soon as I did this the problem was gone. Before I discovered this fix, I would tighten up the engine mount clamps to the point of nearly stripping the treads, have the stopper bolt on the chassis hard up against the engine mount & yet the chain would still be loose after 1 race. It’s because the mount was sitting on the weld & despite all chassis being welded in a jig, not every weld is identically the same so all you need is a slightly higher weld in that one spot & if your engine mount isn’t sitting flush with the rest of the chassis rails that’s when you’ll have this problem. Cheers, Apples
Hey Apples, thanks heaps for the feedback. the engine mount should have a small relief on that side to clear the weld. if your engine mount doesn't have that on it, you can grind/cut/mill a relief on it so that it clears the weld cross pipe. hope that helps. dez
I did a two year stint kart racing at club level in a rotax max about 12 years back. I found it super frustrating and kinda overwhelming with the amount of knowledge required to learn how to setup and re setup the kart and also to learn all the tricks in racing to even come within 1.5 seconds of the leaders. I wish I had found a resource like this back then! All I could find was a few books. I’m now looking at getting back into karting now and finding the wealth of knowledge in your videos awesome. It’s all making so much sense now why I could only get the kart running well a 1/4 of the time. I really had no clue what I was doing….
Instead of wasting money on tyres practising and racing to just gain and solidify bad habits maybe the better plan is to spend a little more and invest into some driver training to get the best out of those expensive tyres. Cheers really enjoying the content.
Hey Sam, thanks heaps for watching and enjoying the content, did you get yo self a new Power Republic hoodie for winter ??
Great Vid Guys!
A few things that may help some people out. First off in X30, I find EGT helps tremendously as on the Tillotson Carby's you don't have the ability to change jets, and adjusting the high and low needle just a few minutes makes a huge difference. Second O-Ring chains are much better in my opinion, I struggled a lot with chain stretch and the O-ring chain eliminated that. I know many people believe it robs HP, but from my experience, any losses are made back by the fact that the O-ring chain lasts much longer and needs less maintenance. Finally, I think that anyone who wants to start Karting regardless of age should go out and do about 3 days of testing/practice in a true race kart, not a rental. You will get a much better understanding of how things work on top of the fact you can really decide if it's something you want to pursue. Many tracks offer Rotax and X30 Kart rentals and a lot of teams at least in the States offer test days. I've seen people invest thousands just to conclude they do not want to race and are left to sell their karts at a loss. I do strongly agree with getting a good 2nd hand Kart at first so you don't have to worry too much about keeping it in pristine shape, you can find some one or two race old karts for thousands off as teams sell them after a couple race weekends!
Hey Sahib, what peak EGT to you aim for on your X30? thanks heaps for your comment !!
@@PowerRepublic Hey! It depends, on a practice day I don’t go higher than 1200-1225F (650-662C) During a race if I need some extra push of the corner I lean it out a little and it may go to 1250F (676c)
I’ve had it go to 1300f (704c) for a brief moment when testing but it never hurt anything. But in general anything around 1200 has worked well for me. The Iame jetting app calls for 1175 f (635c) on average but I’m in southern US so much like Queensland it gets to over well over 100f (37C) and quite humid in the summer, I don’t know how much ambient temp affects EGT a lot but 1250f has been just fine for me!
Good one Dezzy, Old man Na, I remember you as a young tike when I sold you guys kart stuff, and I'm still racing karts. On a run of 3 straight podiums across 2 different classes atm, and the last one was in a red OTK that I had not seen before race day. Keep the vid's coming.
thanks legend
Thank you for your channel! Interesting content
I have a RL leopard and am looking for where to find parts and a top end rebuild kit. Where do you recommend I buy them(I'm in WA). Also should I save up for an x30 (for the tag125 restricted class). Also thanks for answering my other question 😊
Hey D, thanks heaps for tuning in. the X30 is an excellent engine for TAG Res. if you can afford it, get one if you really want to hustle in class racing. otherwise get the bits and fix your RL and go for it
Nice video mate. Can you do a video of a body postioning (arms,legs) in the next video? Thanks
Sure thing
When you install a new piston in a vortex rok do you hone it a bit with a ball hone
Hi, I was wondering if it is normal that with an o-ring chain it seems that the the axel doesn't spin loose like with an non o-ring chain, I believe that the o-ring chain has longer longevity but does the engine loose power through this much more dragging of the final transmission? Also it looks like the chain is a lot wider and very close to the clutch drum, does this may affect the life of the clutch drum itself? thanks in advance
PS Your channel is the best!!!
I have measured it on the dyno and the track and it doesn't change the power output or the lap times. If you are still worried use an O ring for almost all your karting and switch over to the non o ring chains as consumables for very important championship races.
@@PowerRepublic Thank you so much, I really appreciate your feedback, PS you rock!!!
Hello!.I'm going to buy a Rotax Max Evo. Do you recommend the Rotax Max Jetting app or is there someting better? . Thanks
yeah that app is solid, I see heaps of guys at the track using it.
it's actually weird, I keep getting the same recommendation for different weather conditions.
I went to the kart shop at my local track and asked for the recommended jet and the guy shook his head and said nope, get this one. I said blah blah Rotax app told me this. He just replied mate I've been doing this for 30 years trust me 😂
About the water temperature on the Rotax: Will the engine get damaged if your in a race and you cant get the temp below 70 degress celsius?
Not really. The bottom end power normally drops away a tiny bit. But if you are using them in Aus summers when the day temp is over 35 degrees, then good chance they will run into the low 70’s
@@PowerRepublic ahh, thank you. I live in Denmark and it isnt so often we get to high temperatures, so i was just curios🙂
Hello! How do i know which chain lenght should i choose? When i change rear sprocket to smaller one did i must change my chain lenght too?
Hi, what Spec of Air Compressor should O be looking at buying for popping tyres and air line use whilst at home?
I have only a small one on board on the Race Transporter and it works fine
@@PowerRepublic like a 8L? That be good for blowing/drying carb etc?
Also for mitigating water temp on Rotax karts would Redline Water Wetter be a viable option? I have known the product to help supercool the water quite a lot.
I used it on my Rotax in summer it worked well
I haven't tried it, but yeah I have seen it. how many degs does it knock orf???
@@PowerRepublic I've noticed 15°F reduction if I mix in the prescribed amount on the bottle. So about 8-9C drop for you guys down undah 😁
@@Jmasta7 I second this, on top of a decrease in temp it also helps a lot with corrosion. I always use distilled water but I’ve experienced some corrosion due to humidity in the past. Since it doesn’t get below freezing here I leave the water and the water wetter in the engine and I find it stays cleaner than if I would have drained it and left it empty, less rust and oxidizing.
Hi there great vid as always, I just have a question on my senior max evo engine. I’m running a 120 main jet but there are some days the engine will rev all the way to 14000 and over goes really well, but then 1 week later it doesn’t. I thought it was my power valve not cleaned up etc but this week it only went to 13100 rpm. Is this just jetting?( There is no lean popping sound generally pulls well)
Thanks
Sam
geez, 13k is low. nah the PV are normally fine if you haven't got it stick or in upside down. maybe just double check your carby, needle and seat and float level.
also too, if you are having troubles with jetting and weather, maybe start running one of those jetting apps
@@PowerRepublic ok thanks so much for that, i checked the power valve is in fine, so i'll check over the carby etc, is fuel pump worth a go to?
Hi Derek
There's a thing worrying me and that is how hard I should tighten the two bolts holding the Rotax Max engine? It happened once that the engine came loose during a session, and after that I tightened one of the bolts to hard so that the bolt was spinning and a friend helped me with a reparingkit to fix it. There must be a recomended newtonmeter number for the bolts holding the engine right? It will help me a lot if you could help me with this, cause noone I've asked at the track or even at the local store seem to know. I use a pen to mark the bolt how it's tightened but it does'nt feel relaible. Sorry for my bad English :) best regards from a big fan/ Jesper
Ah, I used to blame the chain loosening up on my engine builder...
He was a top bloke and had great motors.
not band
Quick question in regards to rotax engines, is there a serial number to tell me exactly what year and model my rotax is? Have a said non evo with all the evo upgrades.
Thanks in adavnce.
not really once they went to the letter i.d on the cylinder. maybe email Rotax BRP and ask them ?
@@PowerRepublic okay thanks for the reply, I might explore that option.
Hey Power! was wondering is DVS worth while?, I'm in Rotax JNR atm
I just got a Very Used, New to Me 2011 Kosmic, I got it mostly in pieces, I've got all of the major Components, previous Owner cut some tabs off for some reason, That being said, What is the tab at the rear of the inside Axle Cassette that faces left?? What mounts to it??
Send a pic (upload it to imgur than reply with the link)
if it has a M10 thread inside it it, then I reckon it is the chain adjuster bolt/engine mount stopper bolt
@PowerRepublic Thanks Dez for the reply, I figured it out, my kart is a yz/cr 125 shifter kart, that being said, it appears on these the rear sprocket is on the inside of bearing hangers, so it's a chainguard mount, just a through hole, no threads. I'm New too all of this and just learning all of the engine types. Learning alot from You're Videos, keep them Coming!
@@PowerRepublicI did have a question about the tensioner before my latest but figured it out 😂
*or Rocshifter
Hi I have a question I have a Iame X30 and a mycroon 5 and my Temp isn’t showing on my display anymore just wondering if there a way to fix it?
How tight should you actually run your chain?
from memory 1.5-3cm of slack?
@blitzkrieg correct
Hi, could you tell me what the outside diameter of an Iame x30 clutch is? Thanks!
Let me check, you want the drum diameter or the shoes ??
@@PowerRepublic The shoes
⚠️⚠️⚠️ actually, the Rotax manual itself (operating instruction FR125) says 65° as the optimum coolant temp. 45° being the minimum and 85° the maximum. (In Celsius)
maybe but I reckon that at 55 the motors go better than 65. just sayin
No
65 is optimal for longevity 55 is optimal for performance
@@bunta_wrx5851 thank you sir! Where did you get that info tho
@@riccardoarici i've been racing in italy for 11 years my training go kart has a rotax max engine for reliability, i know this engine very well. i can tell by driving that 55°c is faster, especially when the piston has a lot of hours on it if you run hotter the lack of power it's very noticeable. but i guess that if the manual suggests 65 then it's better for engine health
We use 60 C° for the Rotax’s
Actually in the manual says between 45 and 85, with 65 as the optimum operating temperature!
thanks heaps for watching the vid
@@PowerRepublic thank you too for the QnA vid and the answers 🤙🏻😄
In g les