deserate carb measures...Qwicksilver anyone...???

Just curious if anyone has ever heard of anyone, their cousin, barber, mom, dad, sister, brother, some guy down the road or his relatives, has stuck one of these on a WR/YZF?

Those of us blessed with a 98/99 that has one adjustment to the accel pump, and whose carbs have "Been Improved" for 2000 AND 2001, may benefit with one of these Qwicksilvers... ???

David L., you could start all over again with one of these!! :)


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, OEM YZ tank, IMS YZ seat.


I would say don't waste your $$$. After riding now two 99's compared to my '00, I can safely remark there really isn't a great deal of difference.

All 3 bikes are YZ timed, jetted correctly, all free mods, and WB pipes of some sort (I just picked up a Pro-meg Shorty).

The carb we have is state of the art. Why mess with a good thing? I do have a friend that tried one on an XR400. He noticed no real performance difference, although it did start easier when crashed. That bike is long since sold, so I can't comment on long-term reliability.

P.S. Have you checked your compression yet? Your bike carburated fine, it just had no thump. I guess a quick way to check is to see if the kickstarter can hold your weight. If it slips beyond TDC, you're loosing compression. Perhaps either the cyl scoring is the culprit or perhaps a faulty decomp mechanism. Mine will stay compressed indefinately with 200lbs on the kickstarter.

give it a try if you haven't already

Oh yeah, harleys (and most street bikes) have CV carbs (constant velocity) which rely on vacuum to open the slide. These carbs do not give high performance! Rather they give smooth and reliable fuel delivery, needed for street applications.

I'm REAL sure I wouldn't want the FCR on my YZF600R! Talk about a jetting nightmare!


I would sell the bike before sticking on a Qwicksilver pumper. I was curious if anyone has gone this route [maybe someone that owns Qwicksilver... :-) ].

Have not done the compression thing yet, I forgot about it.

I did a mod to my AP, AND stuck the FHP needle back in. I will be test riding it tonight. I also have a simple way of making a timing adjustment to the 98/99's. This mod, coupled with a P38 (or modified OEM AP cover) should make the 98/99's as adjustable as a modified 2K/2001 carb!

Have you done the BK mod to your carb yet, Mike?

I have not done the BK mod yet. Main reason is I've been riding quite a bit and really do not want to foul up a perfectly good riding day/weekend with jetting nightmares. Don't want to mess with a good thing right now as may folks have to rethink the entire jetting game after doing this mod.

Over the winter I'll probably do the mod. That way there will be plenty of testing time before the trails open, and I won't be missing valuable riding time in my garage!

For me, fall is the BEST time to ride. I have the bike setup just about perfectly for me right now--why screw up a good thing when PRIME riding is happening NOW and next two months!

As an added note, I'm also a little hesitant because I feel if I add much more response or power than what I have now, chances are my endurance on long rides would suffer. I generally just don't ride 5 laps and rest--I'm out riding all day with 1 break for lunch. It's tiring enough as is.

I'm also a little concerned regarding statements to keep an eye on the squirt timing. That's definitely one thing I do not want to keep checking.

Another reason--the bike simply has no symptoms of needing the mod. I can whack the throttle w/o bogging.

mcarp, just to play devil's advocate, installing the screw seems like a quick and easy job. Backing the screw off until it is flush, or removing it, will restore the stock condition. That way everything can be fine tuned when you have the time and ambition.

Scott, you may have a point there.

I've also heard conflicting stories regarding which carb this will work on. I have a '00 WR. Some say it won't work, others say yes it will. What's the real story?

I'll still probably wait until winter to do the mod, when the rest of the bike will be in pieces anyway. I've been tweaking on this beast for over a year and half--tired of working on it I Mike68 would say, time to RIDE!


I have a 2000WR and the mod works on my bike. There is clearly an aluminum boss where it looked like there were going to put a adjustment screw.

As for having to screw around with lots of jetting, I did the mod and went one number higher up on the needle EKN#4 to EKN#5. The bike runs as well as before.

There is one area that I am looking forward to regarding getting tired. It seems like the throttle is a little less twichy right off idle. A big benefit when I am getting tired and my right hand gets rubbery. This is just a hunch because I have only driven around the neighborhood since the mod. Towards the end of a 45 min moto when I hit braking bumps my ability to control the throttle gets a little shaky. I think the big 3 second squirt from the AP makes the bike a little jumpy right off idle. The smaller squirt feels like it gives better control, because now the needle is doing more of the fuel metering. The power also feels a little meatier in the middle.

Hopefully all of this will pan out when I take it for a longer ride. On the flip side, my bike ran great before the mod as well, so what the heck, you might just want to ride!


2000WR - EKN#5, 172MJ, 226MAJ, MAJ Passage drilled to 278, 48PJ, 100PAJ, YZ timing, BK mod, 3/4 turn pilot screw, DSP tapered header and pipe, IMS tank & YZ seat, Scotts dampener & triple clamp & Renthal Fatbar 971, White Bros suspension, Dunlop 756's.

The California model KTM's that were street legal came stock with quicksilvers.

Everyone I know threw the stock carb away and put the Dellorto from the dirt model on their bikes to make them run right.

The quicksilver is not a miracle worker.

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