Efi?

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Dballard87

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I'm getting ready to begin my search for a new 450 I was leaning towards a kfx 450 due to the reverse but they seem to be hard to find and fairly expensive when I do find them. My question Is if I do get a yfz ltr or any other 450 should I go with a carb or fuel injection. I know how to work on a carb and I have no idea on fuel injection but I hear EFI helps with start ups and has better throttle response I have also heard a carb has better throttle response so I'm at odds here I'm misinformed please someone tell me what's up :loco:
 
You got it backwards on the throttle response. The efi is better but it involves more electrical components. Carbs are more low tech.

I didn't like how a yfz rode or drove when I rode one but I liked the kfx, it's all personal preference.
 
I would definitely go efi, adjusting the air/fuel mixture is easy with a programmer, maybe even easier than jetting. You'll get more power and throttle response out of an efi system no question. Like you said, efi starts easier too.
 
Alright I really think I'm gonna save the extra money for a 450 with EFI then now I'm just torn between stayin yamaha or going Kwai Weston how do you do in your races against 450's it would take quite a bit of money to build up my warrior? Would I be better off money wise to just go with the 450 there is no replacement for displacement and all ;)?
 
Alright I really think I'm gonna save the extra money for a 450 with EFI then now I'm just torn between stayin yamaha or going Kwai Weston how do you do in your races against 450's it would take quite a bit of money to build up my warrior? Would I be better off money wise to just go with the 450 there is no replacement for displacement and all ;)?

What about a 446 stroker or 460 stroker kit for the warrior:slayer: :evilface:
 
I could build a warrior to run with 450s like I have walle for about the same cost as if you sold the warrior and bought a 450. The warrior will run hotter and turn more heads but if you go head to head with more then your average 450 the warrior won't hang very easily. Which is why I have both. That being said, I've never found a 450 that can out corner walle. They all slide out where walle stays plsnted and digging.

They both have their merits. I just love the 350 platform and I'm convinced its potential was never fully explored.
 
I would definitely go efi, adjusting the air/fuel mixture is easy with a programmer, maybe even easier than jetting. You'll get more power and throttle response out of an efi system no question. Like you said, efi starts easier too.

Easy because it does not require more then pushing buttons, however, not all generic tunes will achieve consistent performance gains. This is where dyno tuning comes in, to get the programming perfected over the entre rpm range, and at all throttle positions. Particularly under load.

Carb tuning can easily be done without a dyno (so can efi, hence the hand held programmer) and all it requires is changing jets and adjusting the mixture screw and jet needle. There is no data acquisition needed like efi, other then plug chopping and feeling the bike.

As to which makes the most power. That is mostly hear say, and depends on the set up and state of tune. They are both fuel metering and delivery devices. One is mechanical and works off of engine vacuum, the other sprays pressurized fuel to atomize it. Horsepower is horsepower is horsepower. Plenty of these single cylinder engines can be built to make 45-60hp, carbed or efi. As for throttle response, I've always felt that carb offers a better "seat of the pants" feel, although efi will always perform smoothly and not be as "abrupt" as a carb can feel. Elevation and weather changes mean nothing to efi as well.

As far as reliability is concerned... I'd have to go carbed. In the case of quads, carbs have always proven themselves. I just feel that there are too many things that can go wrong with efi out in the woods. All it takes is one sensor to fail and you're either dead on the trail, or reduced power. If you get some trash, or water, in the carb, drain it and the fuel and you can go back to riding all day, 99% of the time. Carbs are also super simplistic. Just a fuel tank, fuel line, carb and throttle cable. It's gravity fed (unless you ride a Suzuki) so there is no fuel pump to worry about, or electronics to suffer water damage.

What about a 446 stroker or 460 stroker kit for the warrior:slayer: :evilface:


Waste of money, in my opinion.
 
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Waste of money, in my opinion

I agree lol I was just joking
 
Easy because it does not require more then pushing buttons, however, not all generic tunes will achieve consistent performance gains. This is where dyno tuning comes in, to get the programming perfected over the entre rpm range, and at all throttle positions. Particularly under load.

Carb tuning can easily be done without a dyno (so can efi, hence the hand held programmer) and all it requires is changing jets and adjusting the mixture screw and jet needle. There is no data acquisition needed like efi, other then plug chopping and feeling the bike.

As to which makes the most power. That is mostly hear say, and depends on the set up and state of tune. They are both fuel metering and delivery devices. One is mechanical and works off of engine vacuum, the other sprays pressurized fuel to atomize it. Horsepower is horsepower is horsepower. Plenty of these single cylinder engines can be built to make 45-60hp, carbed or efi. As for throttle response, I've always felt that carb offers a better "seat of the pants" feel, although efi will always perform smoothly and not be as "abrupt" as a carb can feel. Elevation and weather changes mean nothing to efi as well.

As far as reliability is concerned... I'd have to go carbed. In the case of quads, carbs have always proven themselves. I just feel that there are too many things that can go wrong with efi out in the woods. All it takes is one sensor to fail and you're either dead on the trail, or reduced power. If you get some trash, or water, in the carb, drain it and the fuel and you can go back to riding all day, 99% of the time. Carbs are also super simplistic. Just a fuel tank, fuel line, carb and throttle cable. It's gravity fed (unless you ride a Suzuki) so there is no fuel pump to worry about, or electronics to suffer water damage.




Waste of money, in my opinion.
I completely agree with everything you said Pat. However, if efi wasn't better than a carb it wouldn't be taking over the industry...
 
Hey just cuz something takes over doesn't mean it's better they make a **** ton more money off of it guarantee that's a big big factor as well in our modern society full of greedy money grubbing asswholes
 
Hey just cuz something takes over doesn't mean it's better they make a **** ton more money off of it guarantee that's a big big factor as well in our modern society full of greedy money grubbing asswholes
I'm sure they do make more money off it, but still, it's used in automobiles too. Not trying to start an argument, just pointing something out.
 
The Ed I will b e a more be a more reliable tune after it is tuned right. There's no rejecting due to weather. That's why it's taking over the industry, there's too many idiots out there that don't understand how to jet so they made it idiot resistant.

I do agree on the sensor issues. That's why I'm converting my KFx back to a carb.
 
I completely agree with everything you said Pat. However, if efi wasn't better than a carb it wouldn't be taking over the industry...


I'm sure they do make more money off it, but still, it's used in automobiles too. Not trying to start an argument, just pointing something out.


Don't worry, I'm not arguing. Dealt with enough of that on 3ww recently:tdown:.

EFI took over because of emissions and fuel economy. A fuel injected vehicle will run cleaner more consistently because EFI can compensate for elevation, air density, barometric pressure, ambient air temp, intake air temp, etc... That combined with electronically controlled ignition, with a knock sensor, allows the air/fuel mixture to remain a consistent 14.7:1 to allow for the best power results, as well as reduced emissions and fuel economy, over carburetion. EVAP and EGR systems further aid in reducing emissions. Cold starts are not a problem with EFI as well. No pumping the throttle to dump raw fuel into the engine when starting. No using the choke and leaving it on too long. Until the engine reaches operating temp will it burn the air/fuel completely, only then will it produce less emissions.


A carb is simply not going to perform consistently day to day like EFI will. Also, carbs don't like all the emissions control crap that EFI handles. In my opinion, a carb can handle no more then an EVAP line from the fuel tank to the PCV system, to incorporate the EVAP gases from the fuel tank in the air/fuel mixture being burnt, instead of allowing it to vent into the atmosphere. But, emissions equipment was in it's infancy when it debuted during the carbureted era. So, it may actually work half-assed well today, instead of just half-assed, lol:haha:.


I still prefer the simplicity of carbs though. Although EFI isn't all that hard to understand. Carbs just require less to install and run. Fuel pump, check. Fuel pressure regulator (if needed) check. Fuel lines, check. Fuel filter, check. Carb, check. That's just about all that is needed to start and run an engine. Requires much more for any EFI system.

The most simplistic EFI system of all would have to be GM's TBI from 87-95. You can convert any older v8, or 6cy, to TBI with only needing the throttle body, wiring harness, coolant temp sensor, 02 sensor, TPS, IAC, MAP, and ECM. You can cut out everything else from the harness and it literally run only the throttle body. You don't even need the knock sensor, and you can eliminate the electronic spark control. Biggest thing is having the software to "burn" the PROM chips, in some cases. Still tossing around the idea of using TBI on my I6.
 
I completely agree with everything you said Pat. However, if efi wasn't better than a carb it wouldn't be taking over the industry...
The reason its taking over is because its more environmentally friendly thats the only reason. I take a carb any day.
 
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