Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[fxr1234]

what upgrades has every one done to there cv carb and did it help. My other question is what is located under the accelerator pump nozzle on an fxr3 is it a needle valve with or with out spring?

[ltank]

Hi,
 I got a Ness Big Sucker high flow air filter. It holds the carb securely. It mounted easliy was able to use the stock air filter cover with the FXR4 logo. I also got a carb rejet mod kit from Dynojet and that it was easy to install. Nightrider.com has articles on this with links that make it easy. It works quite well. I also have DM500 cam with baffled drag pipes and it starts easy runs great gives 88 inch TC a good run. Put over 22k miles without any problems from it. I can run 4th over 90 mph, 5th gear 3k rpm almost 80 mph. I love it. Idles nice runs great!
Ltank

[grc]

I think the most common mods on the CV40 carbs were drilling out the plug over the idle mixture screw and resetting the idle mixture (start at 2.5 turns out from lightly seated), a #45 pilot jet, then the addition of either a Dyno Jet kit or a Yost Power Tube kit.  Both are still available online and from the major catalogs. 

This is from memory, and my memory is a little suspect, but the stock accel pump discharge tube had a one piece check valve under the tube.  The Dyno Jet kit replaced the tube and the check valve, the latter being replaced by a 1/8" BB with a small cylindrical weight on top of it.  I went down to the basement to see if I still had the box and removed parts from the kit I installed back in '99, but as luck would have it the only part that survived various spring cleanings was the plastic box.


Jerry

[zn14]

K&N air filter, drill out the idle mixture plug and turn it out 2-2 1/2 turns, 45 slow jet, sportster needle and you're done.
go to nightrider.com for detailed info.
no need for yost or a jet kit.

[duranh]

Depends how crazy you want to get, all that they mention is great and should do it for you unless... You can have the thing bored out, and polished up as well.

[Spiderman]

Check out "King" carbs. Last I knew, they did the best job of making the stock Kein really run.

B B

[flyboy321]

Ive been having trouble with my stock carb on my FXR2.  Every time I run it, the hose on the bottom of the carb sends fuel overboard and drains on the ground as quickly as it can until I shut off the fuel flow.  Only happens when running and the fuel is on.  I suspected that something was stuck and I took it apart and was unable to definitively determine the problem.  Any help???

[JonnyD]

Sounds like your VOES is stuck open. Maybe I'm wrong, but the VOES is vacuum operated on the back of the petcock that opens and closes via vacuum. Does it stop flowing gas in the off position?

[flyboy321]

When the bike is off it doesn't flow.  When the bike is running it pours out the little hose on the bottom of the carb.  It continues to pour until I shut off the fuel selector next to the tank.  What kind of fix are we talking about cause Ive never heard of that either, so I don't even know where to begin.  I origionally thought it was a float or a stuck needle but after a cleaning and inspection, it turned up nothing.  Oh and what do you think it is going to run me for parts?

[fxr1234]

did you check for a clear gas tank venting circuit ?

[faceracer]

I think the most common mods on the CV40 carbs were drilling out the plug over the idle mixture screw and resetting the idle mixture (start at 2.5 turns out from lightly seated), a #45 pilot jet, then the addition of either a Dyno Jet kit or a Yost Power Tube kit.  Both are still available online and from the major catalogs. 

This is from memory, and my memory is a little suspect, but the stock accel pump discharge tube had a one piece check valve under the tube.  The Dyno Jet kit replaced the tube and the check valve, the latter being replaced by a 1/8" BB with a small cylindrical weight on top of it.  I went down to the basement to see if I still had the box and removed parts from the kit I installed back in '99, but as luck would have it the only part that survived various spring cleanings was the plastic box.


Jerry

You can also enlarge the hole in the slide with a #31 drill bit to give the throttle a little more snap. I did several of them. May still have one in a box some where!  I still prefer replacing them with an S&S Super "E"   Face

[flyboy321]

OK, so I checked the VOES like the book says and it runs fine.  I decided to rebuild the carb again and I discovered a leaking float.  After replacing that I got the bike running again and its working.  The problem I have now is that it idles fine, but when I give it gas at part throttle, about 2000-3000RPM's it stumbles.  I adjusted the mixture screw like on the cv performance website and I still either get a cough out of the carb or I get a really noticeable stumble.  When I blip the throttle its fine for a second, then when I hit it again, it stumbles.  It also stumbles when I try to hold that same 2000-3000 RPM range.  I'm sure its in the throttle as I have checked everything else: ignition, wiring, timing, crank sensors, etc.  What gives?

[fxr1234]

  what size of jets do you have installed and what needle are you using ? I am using a 45 pilot jet , 80 main and a sporster needle with  no washers under the needle. so far this has been the best combination at sea level. .