Power now plus Boyesen AP cover?

3 replies to this topic
  • kizzle426

Posted March 08, 2006 - 09:36 PM


Alright....so I'm currently banking on some funds and I gt a little money I can blow on parts. My first step is of course (as anyone's should) performance mods. I don't really feel like doing the BK mod because I will never have the spare time to do it. So, I'm wondering how the Boyesen AP cover will act when combined with the Power Now. Anybody have some opinions? And yes, I'm going to do the cam mod but this comes first. Thanks for the help guys.

  • Birdy426

Posted March 08, 2006 - 09:48 PM


I've got both the quickshot and PowerNow on my 426. The PowerNow didn't make a huge difference in performance other than starting on the 426 (but it did make a noticable difference on my son's 250). The quickshot is another story. The bog on my bike wasn't bad, but the improvement in throttle response was really noticable...especially when whacking the throttle on and off and off and on and...you get the idea. If you don't already have the PowerNow, I wolud spend that Benjamin on the cam (I've got hot cams in mine, by far the biggest performance bang for the buck), then the Quickshot, followed by 13.5:1 compression, then a pipe. Although I would work in suspension somewhere between the quickshot and the high comp piston in the overall performance improvement puzzle.

Good luck and happy spending. Post your presults!

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  • Radbuster

Posted March 09, 2006 - 03:48 AM



I have both on my 450. Both the pump cover and power now each seem to require a little bit more juice from the pilot, and together they seem to add up those needs.

It's winter and below freezing right now and I'm on a 48PJ at 1.0 turns and will probably be on a 45 at about 2.0 turns when warmer.

Before the mods the stock 42PJ was pretty good year round.

Have you considered a JD needle? Together with the BK mod it should clean up the jetting pretty well. If it bogs on landings after that, then I'd suggest going to the pump cover.

But! Your accelerator pump membrane har a pretty short lifespan and is cheap, so consider that before putting up serious cash. Pro Circuit changes these in their race bikes every two weeks, but well, that's them. I changed mine after two years and cleared up a really weird problem I was having that was vague and hard to diagnose. Also consider changing all o-rings, choke and hot-start plungers on the carb. Zero bling value, but probably important for best possible response.

Fixing response on the 426 and changing the cam could make it into an awesome bike. :thumbsup:

  • 642MX

Posted March 09, 2006 - 06:07 AM


Get the quick shot and JD Jet kit. You won't be disappointed.

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