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It’s really funny. Dudes post “what’s the next innovation” as we go back to carbs, cable clutches and 2 strokes.
And blue printed Power Vakves.
I want a Boost Bottle. And a torque bar, please. Anyone for fork Gaiters?
I've ridden two strokes with tons of bottom/mid power and they are probably easier to ride for long motos, and overall faster for MX/Offroad. If You're riding pure MX on tracks that are deeply ripped and disked, then having some hit and explosive power can help you do some heater laps and hit big jumps while changing up lines. You can't really have your cake and eat it too with two strokes(unless you're talking big bores), so you ultimately have to decide if more power and a more pronounced "powerband" is more important to you VS low fraction and late moto tractability.
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Just buy a Yamaha already …..
https://www.facebook.com/share/r/1Jg3KGQJbK/?mibextid=adiEgM
Weve all have heard how crappy the tbi 2 strokes sound when free revved. Then I came across cody darrs chest cam footage of chase dashiels holeshot from lorettas. See my post above. I think his still is tbi but does anyone else's that has had ecu mapping run like his??
I am holding out for a twin shocked air cooled ride....
Does it get rid of all the sensors needed for the FI version? That's what seems to be a problem for my friends with the 125s. Bad sensors, bad data, bad connections. Always chasing something new. Our 22 had no sensors and simple wiring, was simple to tune, and was very reliable while being a rocketship with a few mods.
It gets rid of much of the electronics, but not all. The entire throttle body is gone so a few sensors go with that. The electronic PV is still retained.
I fully agree, last gen carb Austrian bikes are the best. But at least this kit might be a savior for some guys that are in TBI hell with problems.
Another company offering a conversion. This looks even cleaner/easier and he does a good job explaining it. Also in English this time.
A lot of people don't really understand how well a carb functions despite its simplicity and the fact that it is very old technology. It is very efficient at atomization and tends to make a little more peak power than EFI because if it. The only downside is that it doesn't tune itself for changes in altitude, temperature, but is very easy to work on to change jets. EFI makes more sense for off-road with significant elevation changes and where a hit in the powerband is a major disadvantage. For pure MX, it is hard to beat a carb on a 2 stroke. For MX, the technical complications of EFI do not really result in benefits that outweigh negatives.
Lectron has been selling carbs that self-compensate for temp/elevation for years. I am not a fan of them for MX, but they work great for offroad riding that spans environmental conditions. They also tend to be smooth and linear and not have the "hit" that most people associate with carbs.
The downside of EFI for offroad, unlike MX, is that you can get far from your truck or home. Not ideal to have some electrical gremlin in the middle of nowhere.
I have both a 19' 300 carb xc and a 27' 300xcw tbi.
Well also had a 20' tpi 300 xcw and yzx 300
Everything is fine with fi until you start having hard to diagnose problems.
I personally know 3 guys that had issues with tbi that put their bikes down for a month or so.
Fuel pump, tps sensor/throttle body, over heating issues.
I can see the attraction to " keep it simple stupid"
Switching over with the pinit racing kit looks to be really easy and the cost isn't all that bad.
My ' carby is such an awesome bike that I kept it and sold the tpi.
Just changing the carb needle shape has a huge effect of how linear or how much hit you have. I just went through this on my Beta. With the stock needle, the hit was enough that you could have the front wheel jumping up shoulder high coming out of corners, which was good for kicks and giggles at first, but a major hindrance and PIA after a short while. I tried several needles and each one had a very different power curve. I didn't want to kill all the midrange it had, but it needed to be tamed down and spread out. Just the simple needle change put more power on both sides of the midrange and kept the front wheel from climbing higher than knee high out of corners and she pulls much better on the over rev. Pretty amazing how tunable they are for old technology.. very quick to make a change and no need to send an ECU out for remapping with a 7-10 day shipping turn around. There is a term called "fit for purpose" that really describes carbs on MX bikes. Fancy, complex computer controlled systems are not always better for MX.
Agree.. nothing worse than electrical gremlins out on the trail or even in the garage.
Interesting. I ride alot. Everyone I ride with, even the yz guys have moved to xc/sx tbi bikes for 2 strokes. I have a good friend that works at carolina ktm.
Through all that 1 person has brought his efi 2 stroke for an issue and the fault was a spark plug without a resistor that is not per the manual and causes the machine to go into limp mode. I personally do not know anyone that has had any issues from these bikes. I am not a ktm schill i have rode and owned everything. I personally belive the tbi "issues" are an internet myth. Ill add from the factory a yz 250 is in no way "faster" than an sx/xc 250. I had both for a short period of time.
I see the allure of wanting a "trouble free, no jetting" experience from TBI, but I personally know multiple people who have had tons of electrical probs on TBI bikes and also piston melt downs and complete engine failures. Also, the facebook TBI groups are completely overloaded with people having TBI electrical gremlins. The worst thing about the TBI bikes is the guys who come along with their anecdotal "well me and my friends are good" evidence and then imply that the issues are made up, or "well it's on facebook so it must be BS!"
In another video, the Pinit Racing guy straight up says that he has literally retired off selling parts and fixes to TBI guys because of all the issues they have.
If you really want that thing to rip, throw a Roost Boost on it.🤣
Pit Row
Facebook have any posts on jetting issues, yz wont start, beta fouling plugs?
I dont understand.
I stand by internet myth. Its no more issues than any other make or models.
Point taken. But I never claimed carb bikes don't come delivered with jetting issues or implied that "my YZ buddies have no issues so there must not be any issues". But, even if I agree that carb bikes had issues to the extent the TBI bikes do, jets are a lot cheaper to buy and easier to replace than TBI parts.
Look at it this way. We now have no less than 2 companies selling carb conversion kits for the TBI bikes. Obviously the need and the demand is there. How many companies sell EFI conversion kits for the YZ250, an extremely popular bike that has been essentially unchanged over 25 years.
I see the appeal for the carb on a 125 and down for the extra juice up top. The 250 and 300s do not apply here. My point is the notion that the efi is more unreliable and or problematic compared to other makes, models or fuel systems is false.
Also people put lectons and smart carbs on yz's to do what? Make them run like an efi machine.
One is not better than the other. That is not my argument. Mine is on the reliability.
It will be interesting to see if the KX327s avoid the various problems that the KTM Group ( and the TMs, it seems, at times - but that seems to be related to the PV, not the EFI?) are having.
Well, at least some of them.
I know around 20+ EFI'd 2T owners personally - only 2 have had any substantial problems. But, Bloody Hell, they Were Substantial problems, and the manufacture / distributor really left them in the lurch!
As to 'fancy' carbs - I wasted a lot of money on a flamin' Smart Carb for my 500 - it was a complete Dud of a thing!
Let's see how The Japanese have done 2T EFI - 'perfecting' it may have been much of the delay in their release, I think.
I can't recall - were there any 4T EFI ' Back to Carb ' kits done / marketed, years ago?
There is not a problem with the technology.. car manufacturers have perfected it from decades ago. The problem is that some motorcycle manufacturers have done a somewhat half ass job when introducing it on their dirt bikes. The problems with KTM's introduction of the TBI on the 2023-25 SX 2 stroke models is well documented;
I think they have the problems worked out, now, but TBI technology is quite simple and it was a rather poor introduction on KTM dirt bikes.
I tend to agree. Car manufacturers had reliable fuel injection since the 90's. Even in harsh off road conditions. That was 30 years ago.
Is there anything that makes 2 stroke injection so much harder?
Or is it just the Euro manufacturers cheaping out or poor implementation?
I ride a YZX250 and have no experiance with the modern 4 strokes. Do they have fuel injection issues? Enough to warrant a carb conversion? Ive never heard of anyone wanting to carb convert there CRF450 etc.
It will be interesting to see how Kawasaki handles the 2 stroke fuel injection. Being Japanese i feel it will be bomb proof, will definately be interesting watching it play out.
Haha a Boost Bottle. They didn’t do much, if anything except look cool. Got one in a old parts tote
Why would TBI on a two-stroke be any less reliable than on a four-stroke? All modern 250,350, and 450 models have fuel injection and for the most part are pretty reliable.
That's the magic question. EFI has, by and large, made MX 4-strokes cleaner running and pretty foolproof. Even eliminated the dreaded cough and stall that would happen sometimes that could be quite dangerous on jump faces and in G-out transitions between rhythm section style jumps. Carbs on 4-stokes could be quite a bear to tune when they didn't run right because you were dealing with an accelerator pump and all that. Yes, EFI 4-strokes have electrical gremlins and they are a PITA to diagnose and fix when they happen, but they don't seem to be anywhere near as frequent as what happens with TBI 2-strokes. People are not asking for a carb conversion on 4-strokes because the Pros far outweigh the cons with EFI on those bikes. "What is different doing EFI on 2-strokes?" Well, 2-strokes get their intake through reeds and the crankcase. The TBI's use a crankcase pressure sensor which is a source of many issues. There's also more variables with a 2-stroke when you start talking fuel mixed with oil, ratios, viscosities, etc. My opinion, I don't think they have EFI on a 2-stroke figured out to the point that the pros outweigh the cons yet. Maybe Kawi will change that.
Fuel injected two stroke motors have been in snowmobiles since the late 90s and in dirtbikes for 10 years. The Austrian current gen TBI works very well and are reliable. Are there lemons? Maybe, but you also have owners ignorant about premix ratio needed to work with installed mapping. TPI owners adding "fuel screws" without understanding impact to fueling and rich/lean conditions. Heck, the TPI owners manual had a specific start up procedure that went ignored and owners revving it and fouling plugs.
Some argue for the simplicity of a carb (debatable) or like carbs dues to familiarity, which of course is personal preference. That said, auto engineering has evolved away from hand crank starters, wooden wheels, drum brakes, and so on. There is a reason that the newest two stroke to the industry (Kawi 327) is fuel injected-it is performance and simplicity of operation.
Also to sorta circle back around, to the og post. Why not just buy a yz? Or carb sx?
Ktm 2 strokes come running like crap from the dealers for the last decade.
Funny how they always run better with the 30 year old pwk.
I dont have a problem with mikuni or efi. Ktm setup tho....
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