Triumphrat

Wombat · 07-27-2005

I have seen in many post on here re modding of carbs that I need to put a copper washer under the needle in the carb,

My confusion is based on:

Does this washer have a part #?
Is it particulat to Keihin carbs?
What are its dimensions?
Might I happen to have one in my tool box?

There are many other questions leading to my overall confusion, but these are related to upgrading my carbs.

Any and all help will be appreciated.

Bob

Slinky · 07-28-2005

No, no part #. It is purely an unofficial mod.

The mod is relevant to any bikes with non-adjustable needles, or even some that do adjust, for fine tuning.

Dimensions, going from memory, the washers I used were 3mm ID (about 1/8").

You would need at least 3, possibly 6 depending on how thick they are and how much you want to raise the needles.

johnyC · 07-28-2005

Wombat,

the copper washers I used came from a pack of 'assorted copper washers' bought from a Halfords auto parts store. The thickness of one (all I used) would be similar to one notch worth on an adjustable needle, it richened up the mid range enough to compensate for the K&N and extra holes in the airbox.

Wombat · 07-28-2005

Thanks Johny,

I have decided to follow your lead on the airbox mods and jetting.

I have no clue as to the spacing on the adjustable needles or even if the needles in my carbs are adjustable.

About how thick would the washer be that i may need to use?

Bob

[ This message was edited by: Wombat on 2005-07-28 02:36 ]

BigVinny · 07-28-2005

In my experience the needles on Keihin CVK carbs are not adjustable but the needles on Mikuni carbs have 3 needle slots. Early models have Mikuni's late models Keihin's.

I rejetted due to fitting pod filters but did not see the need to put copper washers under the Keihin needles. All I set out to do was to increase the fuel flow rate to match the increased air flow rate provided by S&B maxi flow filters which have a lower pneumatic resistance than the restrictive standard airbox.

johnyC · 07-28-2005

Wombat,

the washers I used are about 1.5mm thick, equivelant to moving a notch or two on an adjustable needle, but a bit less scientific. The TBS (Keihin) needle you have is not adjustable, you put the washer beneath the needle (to raise it, making that stage richer) and put it back into the slide to get the same effect.