Hello fellow klxers, For those who switched to a pumper carb with a BB was it worth the $. My klx runs just about perfect (slight surge at 6000 cruise) so just wondering if it's a wow mod or meh. Thanks

 

TNC had long said that the CVK carb was good and poo-pood that the pumper wouldn't add a whole lot. Then he did one and said he should have done that long ago.
I followed in his footsteps and havn't looked back. If you want throttle response, the pumper provides. Your not going to get any more horsies out, but you'll get the torque right away.
Yes, for me, worth the price of admission.

 

This was the primary difference I found. The pumper just made the bike a bit more responsive in the woods.

 

Awesome! Thanks guys

 

LOL!...yeah, I should have known better. It's all you described, but one of my biggest surprises was how altitude tolerant the 36 pumper turned out to be. I really was pretty sure it would take more tweaking for trips to the big mountains than my OEM CVK. I have my 1700' altitude dialed in very clean but not really lean. It's been good well past 12K with just some burbling at the crest of the passes I've done, but it was only for a very short time.

 

I have neither (yet) the big bore kit nor the pumper carb. Both are definitely on my long term "to do" list. I'm not trying to take anything away from either so please don't take my comment that way. But I believe doing the MCM (cam mod) first is the most logical step in terms of performance improvements? And it's free for the DIY'er.

MCM => BB => pumper carb

 

For the average 250 reasons to do the MCM cam timing, 1) it helps mid-range power, 2) if you do the work yourself it is free!

From what I've read over the years the next well spent money is the carb. Again, reasons to do the carb, 1) most riders who put them on stock 250s and jetted them in said it definitely added some serious response, 2) it is second in cost at around $270 new.

Big bores come in different flavors. There are three general ranges, 1) 299cc from AHL (China) at around $200 or less as well as Kawasaki cost of which I don't know, 2) 331cc kits from B&B, I think bored and a liner and I think Athena which is plated, costing around $530 for B&B, not sure about Athena 3) 351cc from B&B bored with a wet liner that takes up a bit of the water jacket, but in most cases that doesn't seem to affect anything, coming in around $550.

Probably an aftermarket header pipe should fit in there somewhere, a shame none of the pipes seem to add much more than a lot of noise and minimal power gain - far less than a TM36-68 for sure. A KLX300 muffler with an aftermarket head pipe would probably be about the best trick. Wish someone would come out with a real muffler slip on, not just a straight thru can. So what if it is slightly bigger, make it oval, and heavier, wouldn't be as heavy as stock and I could lose 10lb to make up for it, a bit of tone with some good flow would be nice. Seems most aftermarket is louder than the MX exhaust systems on the track. There is no excuse for it, the exhaust makers aren't listening to the market. So many riders complain about the noise, that the pipes are too loud, yet nothing is really done to see if it would sell. I ended up with an old Pro Circuit slip on megaphone set up that uses a Supertrapp silencer set up. Same size as my KLX650. I use 12 discs in the 650 and it isn't overly loud, I figure I may be able to drop to six with the 250 considering both Supertrapp silencers are the same size. Should work pretty well and not draw unwanted attention from the constabulary.

 

So far, I have stuck the the CVK because it gives me a little safety buffer from errant whisky-throttle situations....LOL There have been times I could have used a stronger kick to get the front wheel over something, but not often enough to cause me many issues where I ride.

I did however, add a quick-turn throttle and I love it. Stock throttle tube has way too long a pull and means I have to re-grip to use anything near WOT.


I'll be keeping a pumper upgrade somewhere on my list, but honestly, I'm fairly new to off-road riding and am often running right at the edge of my skill level. I've got a ways to go to outgrow the CVK, and am old enough that I don't bounce so good anymore... so staying healthy is a higher priority than being a rock star.

Try a QT throttle... Zeta has one, and G2 has one... there may be others. Not too expensive and changes the personality of the bike for the better.

 

Already have the quick turn throttle tube myself.