Rice#67

Member
Dec 17, 2007
40
0
I have an 01 YZ250... I want to know some opinions on which one worked better in the YZ. The V-force 3 or the Boyesen Rad Valve... I know jetting has to be changed on both so please state if you re-jetted and what was done. If you've tried both, even better...
 

Rice#67

Member
Dec 17, 2007
40
0
Thanks guys, but yes the V-force does require jetting changes regardless of what the manufacterer says. mmz77 is right by saying that comment... I had a 1995 CR125 that I put a V-force 3 on and it richened the bottom so much that the powervalve got loaded with carbon. It stuck in the closed position.

Anything that changes the amount of fuel that goes in the engine is going to need jetting changes...

Anyone else try a V-force or Rad valve on a 2001 YZ250 with good results?
 

gearhead123

Member
Dec 24, 2007
1
0
i just became a member to see if anyone can help me i have a rt 100 yamaha 1990 and put boysen reeds in it and i need a idea about the jet seetings and if anyone konws why my bike wont down shift it would be much appreceated
 

mmz77

Member
Oct 15, 2006
435
0
flounder said:
You may want to freshen up on your english before you criticize others because you're the one who is wrong.
Who ever said I am criticizing anyone? There are a lot of people on here who make stupid mistakes and I just want to clarify them so it stops confusion and possibly problems later down the road...

Usually jetting changes are required while changing out to performance reeds... This is why I thought this was another stupid careless mistake... :ohmy:
 

MX86

Member
Dec 27, 2006
214
0
i run the VF3's on my 2000 yz250 and love em.
 

Rice#67

Member
Dec 17, 2007
40
0
MX86 said:
i run the VF3's on my 2000 yz250 and love em.

MX86, just wondering how much difference did you notice? And also what did you do to the jetting?

...Also, how long have you had them on the bike?
 

MX86

Member
Dec 27, 2006
214
0
this last year was my first season with them in my bike. put on about 110 hours on a race track.

the main thing i noticed is that the bottom end is a lot more crisp and i can go into corners a full gear higher then i could with stock reeds.

for jetting you can run stock (bogs a hair on bottom end if you do). but i have one jet size smaller on the pilot, and one jet smaller on the main (too rich from the factory). seems to work fine for me.
 

Rice#67

Member
Dec 17, 2007
40
0
Cool, it worked good on my 95 CR125 as well. But for some reason in the dyno section on this forum the V-force didn't work well on a 03 YZ125 and had actually lost a little power in the mid and mostly on top. That made me wonder about it a little. It added a bunch on an 02 YZ125 though. Strange.
 

dirtracker

Member
Jun 21, 2006
18
0
mmz77 said:
Who ever said I am criticizing anyone? There are a lot of people on here who make stupid mistakes and I just want to clarify them so it stops confusion and possibly problems later down the road...

Usually jetting changes are required while changing out to performance reeds... This is why I thought this was another stupid careless mistake... :ohmy:[/QUO
In my 02 yz250 when I change my reeds to V Force 3. I did not change my jetting.I run still the stock jetting. Engine runs crispier and more responsive and thats with a procircuit pipe.Only during sumertime above 90 degrees I had to lean out main jet from 178 to 175 and airscrew from 1 to 1 1/2 turn.and that is with pump gas.

In reality if your bike is jetted properly with stock reeds changing to V F 3 most likely will need no or a very little jetting change.You have to ride it feel for it.Often times 1/2 turn airscrew in or out is max all you need or 1 step leaner or richer jetting change is all you need. :nod:
 

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