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Confirming my thoughts. Turds off the bottom and down 5hp from the carb motor.
What pipe is that? Have you tested any that make improvements bottom to top?
Another issue that has been documented is the Elko cylinders cracking(water jacket) seen here.
They switched cylinder manufacturers for 2024(Kymco)
I just mixed some and poured it in. Nothing more. I haven’t modified anything except wheels from Dubya, Bars/Grips by ODI, and the WP split clamps.
Guys were bitching about the Kymco cylinder on the '23 TPI bikes because a guy on Youtube blew one up. The handwringing over this should be interesting to see.
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The kymco cylinder on my 21 250sx looked better than the elko cylinder on my 21 150sx.
The 150 cylinder has a small like porous hole in the outter edge of the water jacket oring groove. Plus the lower edge of the intake skirt had a similar problem.
Only 16 hrs first top end. I just did the 250 top end at 48 hrs. Zero issues with it.
Pic of the 150 cylinder and the piston where you can see the mark it left.
What makes me laugh is how down on EFI so many people are. We have a 2023 SX125 and a 2024 SX250. I agree that RIGHT NOW, EFI isn't as good a carb bikes on this brand new generation. However, EFI can be infinitely programmed so I would say it's highly likely it gets better than carbs, probably within 6 months or less. Let's all recite together, the vehicles that run better with EFI than carbs:
Automobiles
Boats
Motorcycles - Road
Motocycles - Off Road 4 stroke
Snowmobiles - 4 stroke
Snowmobiles - 2 stroke
Many of you guys are like the telephone guy that told me two year ago "5G cell service is a hoax, it will never happen". My response, "huh, they said the same thing about 2G, 3G and 4G. How did that work out for you?"
You do understand some people like to do their own fixes on carbs rather than drive the bike to the dealer and pay to have a brand new bike fixed?
Exactly. Everyone is being priced out of this sport. MX used to be the poor man's motorsport and it's becoming more and more a rich man's sport. We already have expensive, complicated EFI 4-strokes. That's great but it would be nice if we could keep 2-strokes as a cheaper, lighter, less complicated alternative that people could work on themselves.
Who the F needs e-start on a 125??????? Come on !!! It's supposed to be a teenager's bike for kids just getting off minis. Parents can't afford to buy the damn things and kids sure can't scrounge up lawn mowing money to buy it.
I’m all about EFI or whatever when it’s ready, but I will not drive 2 hours to the nearest dealer to pay them to do some sort of flash or reset.
im also 100% content with carburetors and enjoy the tuning aspect of them, hence why im still running a mikuni lol
Yes, the debacle of KTM releasing these TBI bikes with tons of issues is a whole other thing. It definitely would have been nice if they had them perfectly sorted first. I don't have much hope though. They already released the 24's with apparently the exact same mapping. And they had quite the record of shipping the carb bikes with horrendous Mikuni jetting for 6 years!
But, even if they were perfectly tuned, all things being equal, an EFI bike is always going to be more expensive, heavier, more complicated, and more difficult for a DIY'er to work on. That goes against everything people love about 2-strokes - light, cheap, simple, etc.
This.
It's the same marketing approach they took with the thumpers. Manufacturers didn't make much on 2T bikes once they were sold because there wasn't much to break and most riders used aftermarket parts where available to service them.
But start building bikes with 10 times as many expensive, precision internal engine parts, many of which are available only from the OEM, and you have instant revenue streams.
Add the fact that lots of buyers were willing (stupid enough?) to spend 4 figures for a simple tubular exhaust that may or may not do anything worthwhile, and they feel like they know their customer base. You could build a National level 2T for what local C squids spend trying to mod their thumper.
I have no use for a bike I can't tune or fix myself, with my only options being taking it to the dealer or paying some aftermarket tuner hundreds to attach my ECU to his computer for a few minutes to tweak it. No thanks, that's not progress. But it seems to be their marketing plan.
Everyone looking to bleed the customer at every turn.
Sort of takes the fun out of it, no?
Were we separated at birth?
The TPI has been out for 5 years and they are finally abandoning it, they were even bigger turds then these TBI. KTM tested TBI before TPI. But you say 6 months and my 250sx will run as good as my carb 250sx?
That’s not without a aftermarket fix. KTM already got my money and could care less.
I have nothing against EFI but when it sucks I speak up. I think the motor in my TBI 250SX sucks.
You are happy with a 125 that makes 32hp and gets out ran by a 18 year old YZ125 carb motor?
I also have no idea what YouTube you’re talking about.
Must be fun to spend 5 figure money thinking you were getting the best thing since sliced bread, only to discover you were unknowingly enrolled as an R&D associate with continuing, significant financial obligations to participate.
that pic is definitely not two different bikes despite the Facebook caption.
Looks like 2 different bikes to me. In any case, if you go on the FB group, there are multiple 300 TBI owners with cracked cylinders and almost all of them are cracked in that exact same spot just like those pics. It's a common and well-documented issue and KTM has already fixed some for owners.
There is plenty more..
Pit Row
Agreed, but also the simplicity of a carb-fed two stroke and the performance it can produce is a beautiful thing.
It's heart and soul stuff.
I am still greatly interested in these FI two strokes, mainly as the usual / main bike in lieu of a four stroke, so the linear perhaps more boring power and bland sound wouldn't bother me as it would still be 'better' than a four stroke to me, but the good 'old fashioned' two stroke certainly has a place and I hope that continues to be the case.
The problem isn’t bland or boring power, it’s the fact they make no power till like 5,500rpm then die off around 8,500. They do nothing till you’re past 1/4 throttle, they run a like a 125, I love 125’s but dont want my 250 to run like one, the 250sx is a flat out turd off the bottom now. If your racing someone with a similar skill set on a carb sx or yz they will be able to go faster with far less rider input.
Most owners don't agree that it has power like a 125,the Dyno shown says 45 hp, on a Dyno jet that's exactly the same as the older bikes
The pipe certainly makes a huge difference looks like. 10hp at 9000. Crazy. Blows my mind ktm would leave 6 - 10hp in the over rev on the table.
Thru have detuned the 250 since 2013 ,no one wants a firebreathing 250 ,riders like easy to ride 250s mostly
By “power like a 125” I’m referring to no bottom end, lacking mid range drive, dull throttle response, needing to constantly fan the clutch and hold it wide. It makes very little power “off the pipe”. Look at the dyno and compare to carb years, focusing on the difference below 6k rpm.
Most owners are not coming off 250 two stroke mx bikes from the comments I’ve seen and I guess think they should be this soft and lack this much throttle response/bottom.
I have no problem with EFI or times changing but this motor is a turd out of the hole and for throttle response. Spooge drooling down the silencer, fouling plugs proves how poorly they run and is totally unacceptable, period.
There is literally guys cutting socks and putting them around their silencers to catch spooge so it doesn’t drip on to the brake. Stole this pic from FB. TX300 TBI.
IMO the motor needs a O2/afr/egt in the pipe. Most TBI snowmobiles have at least one so the ecu can monitor then compensate and adjust the fueling to run correctly.
My son was pretty disappointed when he picked up his 22 250sx all bottom end no real hard hit and no over rev even Jetted correctly! his old 04 CR250 with a heavily massaged motor was a lot faster! I took the bike to Twisted development they made it hit like a 500 and overrev to the Moon the bike is a rocket ship now LOL probably a little too much LOL
Sounds faulty to me , a pro rider friend has one in UK and it doesn't have any of those issues
Your one friend? A pro rider would be a minority in this situation. There is people posting first hand experience with these bikes throughout social media, documenting the run-ability issues(plug fouling) and now considering spooge “normal”.
Between jetting, oem head volumes and PV spring selection the prior generation was extremely easy to tune to fit the rider.
TBI comes with two maps and no pv adjustment. One map is not usable with the pv only opening 80% and the other the pv opens too soon. The XC and SX now share the same compression ratio and mapping. The days of a ripping 250 smoker are gone.
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