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Boyesen Quickshot question

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What exactly does the QS do? I mean, I know it is an accelerator pump cover that's suppost to improve the AP's function. But how does it function differently than the stock cover.

So far I "think" it fills faster because of it's two fill holes and I "suspect" it provides a longer squirt duration by allowing the pump diaphram to travel further downward. Is that accurate??

I'm not considering buying one but I want to understand them. Yes, I've read the "Rediculous throttle response" thread. Well, the first half of it anyway--it is in DESPERATE need of an edit to cut out all the stuff of no relevence...

thanks

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does it really help prevent hot stalls??

No. The AP only does something when you turn the throttle, if the throttle is closed it can't possibly affect the idle or stalling. It's a gimmick.

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I've tried it and I think my bike ran worse than before the mod. I don't think it does NOTHING. It does something, just not what it claims. I can't believe Transworld wrote up that it was the next best thing since sliced bread. But then again, they said the same about the icat!

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So the QS does or does not allow for more diaphram travel? Has anyone measured the depth of the QS vs. stock right in the center of the bowls?

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For all you doom-sayers, if the QS didn't work and was not a good idea why did Keihin redesign their AP covers for 07 carbs?

Hint, because the QS does make a difference...

Stock AP cover on left, QS on right.

http://i38.photobucket.com/albums/e129/odonnks/P1010027-2.jpg

Look at it this way, IF there is a air space on the bottom side of the AP diaphragm, and you wick the throttle, the compression action the AP linkage tries to force the AP to push fuel. But the stock cover permits the diaphragm to 'deform' into the air space instead of forcing the diaphragm to squirt fuel.

Its like squeezing a balloon full of water trying to empty it. It deforms into available space around it while emitting some water.

Alter the space around the balloon to make it maintain more of its original shape while squeezing it and you'll get more water out faster.

The QS works similarly.

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It worked like great for my 2003 ktm 450sx, changed total throtle reponse and made it run beter all in all. But on my 06 crf450r it does nothing, look for it on ebay this weekend!

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all I can say is this.....I have the QS in my crf 450......I put one on my buddies KXF250 -2006-- and when I took the O.E. cover off it looked EXACTLY the same!....dimensions ,2 fill holes, everything. even the depth and rivet stop were indistinguishable between the 2 covers....so what do i think?

I think keihn has since copied the QS cover and just started machining theirs to be the exactly the same.

as for the bog.... I did the AP mod as described in "sick throttle response" and I'll tell ya.... It works!!! that is what will cure the bog when you snap the throttle off idle....by linking the actuators together, you lose the bog because the fuel squirt is more instant, and by shaving the rivet, you can control the duration( I set mine to bottom out just before WOT.....then you adjust the leakjet to richen or lean the squirt, the mod will probably leave you rich when revving ( small puff of grey smoke from exhaust)...get a few leakjets and go 1 leaner till the grey smoke is no more.

also you may need to lean up the pilot jet too......I had to turn my fuel screw all the way in to get it to start easy (or hot start it).

but when its all said and done, it makes a big difference in the response of the motor. good luck

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126, I agree. The QS did not make as much as a difference as tweeking the AP linkage did.

I run the QS on my WR with tweeked AP linkage.

My CRF has the stock AP cover with the PowerNow inlet vane. IMO that works better than the QS.

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