Rich/lean adjustment by adding/removing washers under the carb needles

[nidyanazo]

Anyone else do this? I pulled the diaphrams (sp?) and removed the needles.. Then went and got plastic washers to place under the needles, to move them up and create a richer mixture an mid/high throttle openings. I have been tuning my carbs for the Vmax's new home, at our lake house (elevation 5,500') so the mixture was a bit off VS sea level in Los Angeles where I used to ride it all the time.

Basically, with 1 washer under the needles, it had the best all around power, good low/mid and a very steady hard pull up to redline.

With no washers, the low/mid range was a bit weaker, but up top when vboost hit, the high end rush was the best. Pulls like a freight train!

With 2 washers, it made an awesome sound, burbling and grumbling on deceleration, but was clearly running rich. Down low it made great power and had good response, but started to break up past 6,000rpm.

For sure a fun little project to fiddle with, and see what your bike likes best for your air/elevation. In the end It's running a bit better so I'm happy.

 

[dingy]

What thickness washers did you use? Stainless or Nylon. quite a bit of experimentation has been done on Ventures for this mod. The S.S. washers are thought to slow down sliders due to being much heavier than nylon washers. The Venture guys are more into mileage out of the bikes than power.

One of our members sells a shim kit for $12, including USA shipping.

http://www.venturerider.org/classif...1983-to-1993-vr-needle-shim-mod-kit-21&cat=22

Gary

 

[Traumahawk]

Usually people will shim to a max of .038. When mine were shimmed, I kept mine at .030.

 

[one2dmax]

One guy sold precision made shims for years that were specifically sized for 1/2 and 3/4 thickness if I remember correctly.

 

[thor_eyerdhal]

Yes i have a link somewhere on this guy.


I am afraid that weigth difference between SS or Nylon doesn't matter....

 

[maleko89]

Yep, Paul Czernics made them...not sure if he still does. I have a couple sets that I got from him 10-15 years ago.

http://home.comcast.net/~onlyone12/carbs1.htm

 

[thor_eyerdhal]

Yes, this the link i was talking about....

 

[tugla]

I would think at 5500 ft vs sea level for sure would need to loose the shim....I assume bikes all stock. might have to drop a jet size instead. and then fine tune with shim as needed.

 

[nidyanazo]

I would think at 5500 ft vs sea level for sure would need to loose the shim....I assume bikes all stock. might have to drop a jet size instead. and then fine tune with shim as needed.

Yeah with no shims it seems to have the best high rpm power- but with 1 shim it had slightly better part throttle response and mid rpm power.. But the bike is not stock at all. Full 4-2-1 headers, slipon, K&N, jets, ign, mosfet r/r, vboost on all the time, modified airbox/stacks, colder plugs and various other mods not pertaining to the engine.