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If you had the choice between a Boyesen Power Valve or Vforce Delta 2 reed valve system for a CR500 that will be used only on MX tracks, which would you choose? The carb, cylinder, and piston are stock. It will have a Pro Circuit works pipe with a PC304 silencer.

Not sure if you are building an AF but the boysen makes it a lot easier to fit everything together.

I have not used Boyesen but I hear it is a pain to get the carb tuned properly with them installed. I love vForce reeds - I had them in my YZ250 and I now have them in my CR500 - they are awesome, not only for the throttle response but they also clean up the jetting quite nicely.

Yes, it's going on an '02 CRF450R conversion. I've got all of the parts together to do the custom fork boot connection per the instructions from another thread. I will be re-jetting in the future when I get the old cylinder ported and re-install it. I'm installing a stock cylinder and piston as a temporary setup so I can ride while the other work is being done.

jetting with rad valve is real similiar to stock reeds. that doesnt seem very difficult to me. might need 1 size bigger or smaller but its real close

100hp honda wrote:jetting with rad valve is real similiar to stock reeds. that doesnt seem very difficult to me. might need 1 size bigger or smaller but its real close

Well like I said I have not used them but I read a post on another site where the author mentioned it being difficult to jet for them but obviously that guy did not know what he was talking about.

i like the rad valve personally and have used them on 2 different bikes. theres definatly no secret to figuring them out

My friend switched his over from stock to boyson and he didn't have to change jetting and the bike runs great.

i have the V force delta 2 cage, and i had to trim the front corners a little so it would fit in the case. it's like it was a little to wide on the piston side and needed to be tapered or something.

I had a VF2 and switched to a RAD becuase I was told by AJ that they are easier to jet. Neither would jet worth a damn with a bad stator/crank seal

Since that's been fixed I have been running the RAD. It jets fine.

I run a rad valve myself, but dont do any mx Had a vf2 on a yz250, Went back to stock. My .02.

LAYNFRM wrote:i have the V force delta 2 cage, and i had to trim the front corners a little so it would fit in the case. it's like it was a little to wide on the piston side and needed to be tapered or something.

I had to hit mine with a dremel too but not on the front egdes,had to make the cage a bit narrower on the L & R side near the sealing surface so it would seat properly,I know theres a few more guys who have had to do it like this,no big deal really,takes a few minutes,been running it for 2 seasons,prolly 7 or 8 months total and it still looks and performs as when I put it on,no complaints here

kkvslayer wrote: I had to hit mine with a dremel too but not on the front egdes,had to make the cage a bit narrower on the L & R side near the sealing surface so it would seat properly,I know theres a few more guys who have had to do it like this,no big deal really,takes a few minutes,been running it for 2 seasons,prolly 7 or 8 months total and it still looks and performs as when I put it on,no complaints here

Same here.

only '85-'88 jugs need the sides to be trimmed.
I like the vforce, they will last longer than a rad valve and flow the most by design. the downside is the shape on the inside relating to flow through the air boot. it opens up to a perfect rectangle from the oval shape of the boot and creates turbulance. the quick fix is the trim the boot to match. makes a noticeable difference.
my gen-1 is running the vforce where I modified the reed cage inside and out and modified the boot so they are both very large and oval shaped. made a big difference w/ the 41mm carb on there.

I don't see any reason to install a set on a stock bike. OEM reeds are killer in a stock or mildly modified setup. I prefere the vforce on a built setup because the pedals are stronger and the whole assembly flows more which comes in handy with a lot of porting and a larger carb. On a stock bike, I hear they are supposed to improve throttle response, but thats about it.

Thanks for the input. I think I'll wait until I get the old cylinders ported and other pistons to install the reeds. I'll stick with stock until then.

FattyFive wrote:I run a rad valve myself, but dont do any mx Had a vf2 on a yz250, Went back to stock. My .02.

My 2003 YZ250 fouled plugs because of rich low end jetting right from the shop when new. I put in the vForce 3 reeds and never fouled a plug after (perfect brownish-gray plugs) and I noticed improved throttle response as well. That is about all I noticed with the vForce but that alone made them worth having. I bought the same for my CR500.