Pumper carb - is it worth it?
#1
04-20-2009, 10:45 PM
Join Date: Jun 2008
Location: So Cal
Posts: 1,356
Pumper carb - is it worth it?
I'd like to hear from people that have them and how the carb works for them.
Which carb do you have? What are your other mods?
How does it compare to the stock CVK carb? More power?
How bad did it effect your gas mileage?
Lastly- Any negatives/problems?
Which carb do you have? What are your other mods?
How does it compare to the stock CVK carb? More power?
How bad did it effect your gas mileage?
Lastly- Any negatives/problems?
#2
04-20-2009, 11:59 PM
I got an FCR35 second hand that had been fitted to a KLX300. It took some work (read, new spigot and airbox adapter) to fit my KLX250 but otherwise bolted straight up. It was a stroker modified unit, so jetted OK for the 300. My KLX has a Bill Blue 331 big bore kit fitted and FMF Powercore 4 exhaust .
Compared with the stock, it's worth it for my type of riding, which is off road, enduro style. It doesn't give more power, what it does is give more response - when you first twist the throttle from closed with the CVK you can feel the engine build power, after .5sec it's building, after 1sec it's building, after 1.5sec it's delivering all it can for that part of the rev range.
Do the same with the FCR and it 'leaps forward' - it delivers that 1.5sec power level straight away. However, it doesn't give more overall power.
Depending on your riding style it can affect fuel usage. If you're on throttle brake on throttle brake with your riding it will use more juice since the accelerator pump is squirting fuel into the engine more. However if you're smooth and measured it makes no difference at all.
No negatives. I use only the one throttle cable, the one without the kink in it. Otherwise stock throttle grip. For offroad where you want power NOW to lift over a log or ugly pothole, or to hang the back out in endless amusement, it's the best thing ever. For onroad city cruising, I doubt it's useful past doing easier monos.
Compared with the stock, it's worth it for my type of riding, which is off road, enduro style. It doesn't give more power, what it does is give more response - when you first twist the throttle from closed with the CVK you can feel the engine build power, after .5sec it's building, after 1sec it's building, after 1.5sec it's delivering all it can for that part of the rev range.
Do the same with the FCR and it 'leaps forward' - it delivers that 1.5sec power level straight away. However, it doesn't give more overall power.
Depending on your riding style it can affect fuel usage. If you're on throttle brake on throttle brake with your riding it will use more juice since the accelerator pump is squirting fuel into the engine more. However if you're smooth and measured it makes no difference at all.
No negatives. I use only the one throttle cable, the one without the kink in it. Otherwise stock throttle grip. For offroad where you want power NOW to lift over a log or ugly pothole, or to hang the back out in endless amusement, it's the best thing ever. For onroad city cruising, I doubt it's useful past doing easier monos.
#3
04-21-2009, 12:07 AM
I had the mikuni. I went back to the stock carb with a dyno jet kit once i upgraded too the 300cc. The only difference is in throttle responce. I am not a racer so for me it was not worth it. i sold it and put the money into the 300cc upgrade which by far make more power than all other mods.
#4
04-21-2009, 01:33 AM
I went with the Mikuni from Bill Blue.
For my type of riding, off road, it's well worth it.
Combined with the 300 kit and pipe, I am happy with the result.
The CV carb is fine for tootling around town but not much good for the hard on, hard off style used on the trails.
IMO it was the best single mod I did.
For my type of riding, off road, it's well worth it.
Combined with the 300 kit and pipe, I am happy with the result.
The CV carb is fine for tootling around town but not much good for the hard on, hard off style used on the trails.
IMO it was the best single mod I did.
#5
04-21-2009, 02:12 AM
I got an FCR35 second hand that had been fitted to a KLX300. It took some work (read, new spigot and airbox adapter) to fit my KLX250 but otherwise bolted straight up. It was a stroker modified unit, so jetted OK for the 300. My KLX has a Bill Blue 331 big bore kit fitted and FMF Powercore 4 exhaust .
Compared with the stock, it's worth it for my type of riding, which is off road, enduro style. It doesn't give more power, what it does is give more response - when you first twist the throttle from closed with the CVK you can feel the engine build power, after .5sec it's building, after 1sec it's building, after 1.5sec it's delivering all it can for that part of the rev range.
Do the same with the FCR and it 'leaps forward' - it delivers that 1.5sec power level straight away. However, it doesn't give more overall power.
Depending on your riding style it can affect fuel usage. If you're on throttle brake on throttle brake with your riding it will use more juice since the accelerator pump is squirting fuel into the engine more. However if you're smooth and measured it makes no difference at all.
No negatives. I use only the one throttle cable, the one without the kink in it. Otherwise stock throttle grip. For offroad where you want power NOW to lift over a log or ugly pothole, or to hang the back out in endless amusement, it's the best thing ever. For onroad city cruising, I doubt it's useful past doing easier monos.
Compared with the stock, it's worth it for my type of riding, which is off road, enduro style. It doesn't give more power, what it does is give more response - when you first twist the throttle from closed with the CVK you can feel the engine build power, after .5sec it's building, after 1sec it's building, after 1.5sec it's delivering all it can for that part of the rev range.
Do the same with the FCR and it 'leaps forward' - it delivers that 1.5sec power level straight away. However, it doesn't give more overall power.
Depending on your riding style it can affect fuel usage. If you're on throttle brake on throttle brake with your riding it will use more juice since the accelerator pump is squirting fuel into the engine more. However if you're smooth and measured it makes no difference at all.
No negatives. I use only the one throttle cable, the one without the kink in it. Otherwise stock throttle grip. For offroad where you want power NOW to lift over a log or ugly pothole, or to hang the back out in endless amusement, it's the best thing ever. For onroad city cruising, I doubt it's useful past doing easier monos.
#6
04-21-2009, 03:03 AM
Interesting... Throttle response has always been the biggest problem with the stock KLX. Espacially with log crossings. I usually just throttle my way over the logs with the front wheel in the air on my two stroke bike. Instant throttle response has got me out of a bunch of jams off road over the years. Most times it's easier to 'throttle' your way out of an immediate dilema. In fact, my 'knee jerk, holy crap' response has been to gas the bike to safety and it's worked beautifully much of the time rather than 'freezing up' but that's really a learned tactic and you have to have a bike capable of such a thing.
I personally have gotten a bit better at 'throttling' myself out of situations with the KLX although it takes longer and requires clutch use alot of times. You just have to plan on giving the bike that extra time to give you the power you need as kbekus has described.
Mike
I personally have gotten a bit better at 'throttling' myself out of situations with the KLX although it takes longer and requires clutch use alot of times. You just have to plan on giving the bike that extra time to give you the power you need as kbekus has described.
Mike
#7
04-21-2009, 04:22 AM
Join Date: Jun 2008
Location: So Cal
Posts: 1,356
kbekus - well put!
The only problem I've encountered is the fsw supplied cable mount, since the oem keihin cable bracket hits the frame headstay crossmember. The cable operates at the wrong angle, and has cut a groove into the threaded end of the cable:
The only problem I've encountered is the fsw supplied cable mount, since the oem keihin cable bracket hits the frame headstay crossmember. The cable operates at the wrong angle, and has cut a groove into the threaded end of the cable:
Last edited by RaceGass; 05-21-2009 at 01:14 AM.
#8
04-21-2009, 05:33 AM
Not worth the money IMO. I have one a buddy doesn't. We both have the BB331 kit. Gas milage is similar and so is the power. Neither bike as any perceptable advantage over the other outside of the rider. Sometimes I can't stay with him and sometimes he can't stay with me.
#9
04-21-2009, 06:20 AM
2 things no-one else has mentioned, 1 positive 1 negative.
Positive:
No more cold starting problems, twist the throttle once or twice, choke on when cold, fires straight up.
Negative:
Can be a little jerky under small throttle movements. In other words in traffic just tooling along it is not as smooth as the CVK. If you don't ride on the road you won't notice it.
Positive:
No more cold starting problems, twist the throttle once or twice, choke on when cold, fires straight up.
Negative:
Can be a little jerky under small throttle movements. In other words in traffic just tooling along it is not as smooth as the CVK. If you don't ride on the road you won't notice it.